Losing fuel pressure after sitting. At that age, all fuel hoses should be replaced.

He just recently changed the fuel filter thinking that was the problem. now i have to hit it with ether every morning to get it started. It has great fuel pressure now so I don't think it's the fuel system. I pushed valve in on fuel rail after trying to start no fuel pressure. Mar 24, 2022 · If it does, the CPU could read codes P0087 (low fuel pressure) and P0190 (low fuel pressure inside the fuel rail) could indicate a low fuel pressure issue. Apr 11, 2010 · Assuming it's not leaking anywhere, is there anything that can cause this other than a failing fuel pressure regulator allowing fuel to leak back to the tank out of the rail? About half the time after the Jeep has been sitting a few hours or more, it takes a couple extra seconds to start up. also if your airdog is mounted Jun 12, 2017 · * Even though the fuel lines are new, IF there was a puncture in the fuel line between bulb and tank, thereby pulling air instead of fuel, I would notice this fuel leak as it flowed into my bilge. Found could not attain and hold fuel pressure above 21k psi. When you put the key in the ignition but don’t start the truck, the fuel pump primes the system putting it back at the proper pressure. Owner said it ran when parked has 167k miles will not start tries is getting spark. Aug 15, 2018 · My fuel system seems to be losing pressure immediately after shutting down. On restart truck will start after high pressure rebuild back to 1700 psi low psi stays at 60-70psi I think it would be the pressure regulator. When I disconnect the vacuum hose from the fuel pressure regulator, the pressure rises to 46 psi, and the engine continues to run OK. 3 and it has difficulty starting after sitting out overnight. I was still having the problem So i kept priming hoping to find a leak. 0 losing fuel pressure. Fuel pressure should hold for weeks. Codes PO171,PO174 come up. i have a 2008 lmm. we changed the ECM still throught that code truck is bone stock. Injector or a few could be leaking, letting off the pressure. See if this resolves your issue. Feb 12, 2012 · If no leaks are visible, a loss in engine-off fuel pressure is usually one of three things; a bad check valve at the fuel pump, leaky injector(s), or a leaky fuel pressure regulator. Mar 30, 2013 · The fuel system doesn't hold pressure, I have old school ISSPRO mechanical fuel pressure gauge, it drops to zero shortly after the engine is shut down. Oct 17, 2018 · 1999 to 2016 Super Duty - F250 6. 7 liter series 60 Detroit engine (500hp). Apr 27, 2011 · I recently swapped a 91 7. Starter engages, turns engine over at the expected rate, engine struggles to ignite for about a second and a half longer than normal, then fires off. We have tried running a fass lift pump. its losing its prime after sitting for about an hour. Feb 9, 2023 · 2015 - 2020 Ford F150 - Losing fuel pressure - I'm losing fuel fuel pressure after truck sit 2hrs ️. Dec 22, 2023 · Yes, I tried a new regulator, vcv, drivers side fuel rail, removed return lines to check for fuel as well as blocking off high pressure side on each injector and still loosing pressure. this has happened Jun 21, 2013 · 2001 2500HD Sierra w/6. Jul 16, 2013 · The check valve should be between tank & filter if it is present. The problem is that it is loosing prime when sitting overnight and is hard to start. Feb 15, 2021 · Immediate problem: Fuel pressure tests showed low fuel pressure when running, and faster than acceptable pressure losses after shutdown, resulting in 0 PSI at the fuel rail after sitting overnight. A fuel system which uses a returnless fuel system does hold pressure when the car is off but this doesnt apply to our cars. Jun 5, 2012 · You can do this but an electric pump will be required. Nov 11, 2010 · After installing new injectors, fuel filter, fuel pump and pulsator, my 85 held most of its pressure overnight, I think it dropped about 12psi. ” I’ll show you where that is in the video below. disconnect fuel pump for test. There is some improvement, but it still takes me 3-5 seconds of cranking the starter for it to fire after it has been sitting for a while. if the pressure bleeds down to ~60psi and STOPS, you have high pressure fuel side leak. Quick edit, you may want to pinch the return line for the 5 minutes and see if the pressure keeps falling. If there is something wrong with the fuel pressure regulator, it can create too low or too high fuel pressure in the rail. I would check the input to the vp44 for a good seal with lines and if you have the pressure sensor right before the vp44 it could be there. Command the fuel pressure control to 180 MPa with a scan tool. Jul 14, 2008 · Im presuming its fuel pressure regulator possibly and or somwhere on the fuel rail its losing pressure over night, is it possible a injector is leaking, where and how can i check fuel pressure at the fuel rail, can i use a tire pressure gauge? I have already replaced the Fuel filter with a brand new Fram about a week ago. 3 non turbo. 3L Power Stroke Diesel - Loss of fuel in system after sitting - Okay, I figured out that my truck looses the prime on the fuel system if it sits overnight. 6L Duramax diesel. Ive checked Intake gasket with carb cleaner, cleaned maf sensor, put new air filter in. I had to go back and forth a number Dec 1, 2015 · To be able to get it to start the truck has to be primed with the key and then put the gas pedal to the floor while cranking. The other day after sitting all night it nearly flooded trying to get started. Your fuel system is losing prime it sounds like. But (here's the weird part) after it does that once, it works normally thereafter. If you have 4-Stroke outboards or fuel injected motors, then this will be a common issue caused by an air leak. Icp and ipr numbers are good, no codes or performance problems and no signs of aerated fuel. Even tried letting it turn over for a bit without a budge from 0 on the fuel pressure. So I turn the key on, and the pressure shoots up to 48 psi, then after the pump shuts down it settles at 40 psi. Jul 19, 2018 · 2017+ Super Duty - Checking fuel pressure 6. If I hold valve in and have May 12, 2013 · if it does it after sitting for a long period of time, turning the key on , to let the pump prime is not enough to prime the system, a typical priming after a complete system drain is , 4-6 times / cycles, also our trucks are equiped with a 25 sec run/fail, wich means if you bump the key on to start the pump runs for 25 secs, turning the key on is to put pressure on the injectors not to re prime Jun 16, 2021 · So, I deduced that it is losing pressure somehow after I park it for the day/night. I was sure it must be the check valve in the fuel pump assembly, so I replaced the entire FP assembly. That can prime the carb for you before you try and start it. Turning the key to the on position the first time only bumped the pressure up a little. then runs fine. Jun 20, 2012 · did you ever figure out what was causing your P060b code my truck is throwing that code the dealership changed the oil and fuel filter said it needed a injector and fuel pressure regulator. Unless you have a cracked filter cap or bad line, the fuel system to the upper filter will purge when the truck gets turned on, and the fuel pump runs. May 1, 2018 · The truck runs and drives just fine but at about 2300 rpm the fuel just stops coming in. Start and warm engine and record fuel pressure. Trying to pinpoint this occasional long cranking hot or cold. Jul 29, 2019 · The fuel pressure in my 2004 Tahoe drops to zero immediately after key-on prime (Prime: The pump runs for about 2 sec. Jun 28, 2009 · The truck is a 98 Western Star with a 12. Edge EZ, PPE Boost Valve, Denali Grill, 285/75-16 Geolander AT/S, Racor underhood primary fuel filter , Dual OEM tranny coolers, Bilsteins. 34 psi when key turned to run position then 0 when I check in the morning. I installed the rail gauge right before the instalation. A mid to high-range scanner can direct you to the issue. Just wondering if there is a fuel check valve in the pump that could be leaking pressure Jan 28, 2018 · The issue causing the loss of prime with my Volvo d12 looks to have been the lower fuel filter. ohyea1 New Member Posts: 3 Joined: Mon Jul 24, 2017 7:21 pm but after sitting for the weekend Jul 19, 2012 · A friends LLY is losing fuel pressure. So as long as your system is building pressure when you turn the key on you are good to go. Apr 10, 2023 · Learn why fuel pressure drops after sitting and how to fix it. Next time you’re having trouble starting try holding down the gas pedal while cranking. I did a fuel pressure test just on the schrader valve of the fuel rail and it barely even registered when I would click the key on. Any suggestions? Dec 11, 2010 · My truck loses prime after i let it sit on a grade for longer then 2 days, if its on flat ground, or only sits overnight or a day then it starts right up. measuring the fuel pressure will show quickly if it has a problem. Sometimes, not often, once a month or so my truck at start up won't fire, just turns over. It will chuggingly restart after a few 10 second cranks and then smooth out and run fine. to/c/26/i/fuel-sending-unitIs your vehicle hard to start, especially after sitting? Does it stall out, or l Jul 14, 2014 · Rebuilt the Fuel Filter Primer, Replaced the WIF sensor and the bleeder screw. Maybe it was a placeabo or because the pump was new but it seemed to help. Apr 8, 2013 · The problem I recently started experiencing is that the boat loses prime after you anchor or dock for 20 mins. Glow plugs arent an issue. The pump churns up until the regulator hits the pressure and then the pumps turns off at the right pressure. I have to hand prime the truck every time I go to crank it. Post up the initial value. Prime system and monitor Pressure. On warm mornings, it cranks for a couple seconds before turning over. Seems like a low fuel pressure issue — regardless of tank selection, if I prime the system (turn key 4x to pos 2/wait to start, wait 15 sec per fuel pump prime) it fires right up. Normal ECM operation of the Lift Pump is when key is turned on, LP runs for about 2 seconds, Then when you hit the starter it energizes for about 25 seconds, if the engine starts it continues to Aug 27, 2009 · It has developed this hard starting issue after sitting just overnight. The two coming right off the filter to the motor were the consistency of chewing gum when I removed them. Pressure drops, its check valve or injectors. Nov 2, 2011 · hi all,,just joined. I replaced the fuel pump, since the stealer said that was the problem. Apr 22, 2010 · 1999 - 2003 7. If it's sat for more than three days or so, I typically "bump" the starter and let the lift pump cycle to reduce crank times. i ve been racking my brain as to what the hell is wrong with fuel system. after turning then moter off, the presure lowered to 30 psi where it stopped or appered to any way. Not sure if this started before the supercharger instalation or after. Increased fuel pressure, more consistent fuel pressure, smoother idle, better throttle response. I have recently replaced the fuel filter, air filter, and fuel pressure regulator in attempt to fix this problem. FIXED! Dec 10, 2017 · Once the fuel bowl is full and the needle valve(s) closes no more fuel can fill the bowl. connecting fuel pressure gauge May 18, 2020 · Electric pumps deliver gobs of fuel pressure almost immediately, which is one of the things that helps fuel-injected cars start even if they’ve been sitting for a long time. Pressure will decrease at this rate normally" or something like that, so I'd assume you'll get down to nearly 0 pressure with an overnight sitting. go out to it, turn the key on, everything cycles, then cranks. When I go back to start it within an hour I cant get it to fire unless its turned over several times and I hit the gas. If you have a leak its in the line connections. I believe it is fuel pressure related. I am convinced that the fuel bowl is holding pressure. Install a 0-60 or 0-100 psi fuel pressure gauge to adapter tool 6976 (Figure 2). Back in the day we called this vapor lock, which simply meant that the fuel turned to vapor before getting to the engine. Based simply on the strong fuel smell I'd guess a leaky injector. While manually priming the truck I built enough pressure for fuel to spray out between the fuel filter and the housing. 3 with dp f5 tuner I lose fuel pressure after I start driving. the truck starts for about 5 sec, then dies. 0 PSI 2- Cranking over the engine. I know theres gotta be some sort of check ball or somethin in housing that the fuel filter bolts up onto but it aint workin i guess. Pressurize the fuel rail and put a gauge on the test port if one is available. You will have about $3-400 in a diy setup, but the benifits far outway the initial cost. Aug 21, 2007 · On my 5. The second one is just below my fuel gauge reads off the stock fuel filter head using a bleed screw adapter. I also assume I may need to tightent he fuel filter/water seperator. When I removed the fuel filter, I observed the rubber gasket was "swollen", and not sitting in it's groove on top of the fuel filter. Finally lifted the bed to find a SEVERELY rusted fuel tank sending unit. Mar 8, 2013 · My car has been hard starting lately, you have to crank it for about a minute to get it to start if its sat overnight. Pressure stays normal. After turning off the key, document the time it takes for the pressure to leak down, and what the pressure is at, say, 5 min. Jul 22, 2013 · Took it to a garage and was quoted $850 to replace the fuel filter and pump - it was losing all fuel pressure when the key was turned off. The CP3 "pulls" fuel from the fuel filter, so you won't see or detect that these lines are leaking most of the time, but they will draw in air, and this is what can lead to you loosing prime after a day or two if the truck sits. Since fuel pumps/fuel pressure seem to be one of the more common problems, would it make since to install a permanent ck valve? Could this part be used as a permanent ck valve? (Mr. 3, 4wd, w/195kmiles (updated 08/06/2022) * FYI - anything I say that sounds like a statement is being misinterpreted by the presentation of my dementia. This is because of how cold the temperature gets overnight and how cold the gas becomes inside the tank. The first day I stopped and started again a number of times, but total miles were about 300. com http://1aau. Detailed symptoms:-When running, car showed 40 PSI at the fuel rail, and dropped to 16 PSI after 90 mins. When the truck is turned off the fuel pressure reads strong but when running fuel pressure begins to drop off. we use to get the 0087 code tip we went and got some mods done and had lift pumps put on 4 of our trucks. This makes it harder to start. After driving for approximately 10 minutes/6 miles, I gradually lose all but a couple psi of fuel pressure. It In this video Eric O. When I first start it up I have 80-85psi measured at the passenger side head and sitting there idling it'll hold there. Jan 2, 2021 · The fuel lines will always lose pressure if sitting for awhile. It Customer: 2012 mack vision mp8 engine fuel is loosing prime after sitting over night also what hours power setting will it get best fuel mileage thanks Answered by Mike Mcmillan in 4 mins 4 years ago Oct 21, 2017 · 2008 Sprinter 2500 170 - camper van. Dec 26, 2012 · Mine will also start better when parked on a slight incline. Feb 21, 2010 · Most likely due to fuel evaporating from the carb. I did try turning the yellow valveand yes, it did piss out fuel. The engines store fuel in either a VST or an FSM. Oct 26, 2010 · After I thought I had solved my no start/no fuel issue, I now find that after sitting for just a little while, it loses prime. No codes whats so ever. May 13, 2014 · My 2002 Subaru Outback loses fuel pressure when I shut it off and is hard to restart. Somehow if the truck sits 10 hours or more, the fuel system drains back to the tank and I have to pull a slug of air through the entire system each Aug 3, 2005 · I replaced the obvious - fuel filter, plugs and wires and still the same. 2001 Suburban LT 2WD, 5. Uhnope! Still have the issue. But if there's insufficient fuel in the line from it having drained out & back down to the gas tank it's going to cause a slow start caused by the extra time it takes for the fuel pump to get gas back up to the fuel rail. 0, I left the fuel pressure gauge connected for a week without running. Once hard, crank duration should be normal again. Ive replaced the fuel pressure regulator and ICV. 5L ecoboost any Info would be helpful Dec 25, 2019 · Hey. flex fuel engines run at lower pressure around 45-54psi with regulator line disconnected. May 19, 2021 · Vehicle Details. So I checked the fuel pressure this morning before starting the car, and nothing, nada, zip. If not then you know it's the Fuel pressure regulator. Remember, as fuel is drawn it creates a vacuum & u will most likely not see the problem area. When the pressure drops to about 6 psi off the LP and to 5 psi off the engine, I’ll know it’s time to change filters. Regulator is bad. 8. 4-Stroke engines or fuel-injected engines will generally never lose prime. Jan 30, 2016 · My Avalon did that once after sitting for 2 to 3 weeks, If it sits a while now, I will turn key to on, but do not try to start, Wait like one minute, then start, works every time, Any car could lose fuel pressure after sitting, Also since it sits a lot. Oct 10, 2023 · Check the fuel pressure at the rail in the morning before turning the key on. intervals after key off. Now the return lines send the fuel back when the car is turned off. If it smells like fuel went down it then it's probably a bad regulator. If the truck is under 80K miles, it should be covered under the 8/80 extended federal emissions warranty. Wondering if someone can analyse datalogs. 6 Fuel Rail pressure question - I got a 1999 F150 has been sitting around a year I just bought it. After I rule out the filter and oil level, I will check the pressure. 7. Apr 3, 2022 · So since I posted last my truck has gone to a chevy dealership and a local diesel shop I ended up having my local diesel shop replace the CP3 pump and a injector when I went to pick it up the week before christmas they told me that the truck kept losing prime if it sat over a day and they were guessing it was because of the Black Market performance cat fuel filter lift pump I installed to Feb 17, 2020 · I have a 95’ f250 7. Customer: My truck is losing fuel pressure overnight - no leaks, no codes, initial start in the morning takes forever then cranks and runs fine - changed all injectors, cleaned throttle body and mass air flow, changed fuel pump twice, checked temperature sensor to make sure it didnt think it was colder than it was, does it in hot or cold weather also has a valve clatter when under a load until Jan 15, 2017 · Started up great but I let the fuel level get to low and it ran out of gas on the way to the gas station. you can to the downhill parking as well as wipe all fuel lines down and start the truck and look for leaks which you probably have already tried. Replaced fuel injection pump - could attain full fuel rail pressure but still loose prime over time and hard start. - No fix 4. It runs perfect once it has started. Pump has an anti drain-back valve. I’ve got an in-tank pump and a return line running to the Mar 31, 2014 · The actual fuel pressure should be the same as the commanded pressure. You need to get a gauge to check fuel lift pressure, then you need to know what the rail pressure is while cranking via a electronis gauge or a scan tool. Truck has new lines filter and pump as of 2 months ago and nee fuel regulator last summer. Another thing is the pump priming event. May 22, 2013 · My 1978 280z slowly loses fuel pressure overnight. Feb 22, 2013 · but. Losing fuel pressure after sitting outside; How to relieve fuel pressure Apr 9, 2022 · It does have check valve built in. If there’s no pressure it’s leaking down. Hook your fuel pressure gauge up to the fuel pressure test port. i just installed an electric fuel pump between the tank and the manual pumpno good. In regards to replacing a q-jet, I purchased mine for that exact reason. pop the hood, prime the filter, go back, cycle key, waity to start, cranks longer, then fires and runs fine till she sits. If the pressure no longer bleeds down, pull out the regulator and look at the smaller rubber o-ring on the tube. I can hear the fuel pump running during the priming cycle and would typically see fuel pressure on the regulator at this point. when the key is first turned). But once it starts in runs perfect and always starts fine. Oct 24, 2011 · 3. If you have a vehicle that you don't drive daily, then it is very common for the fuel pump to die after a car has been sitting overnight. I am way to cheap for that, so I replaced the fuel pump the other day. if that's normal that's good news to me. Priming the system with the original Honda pump I see 32-35psi at a prime. If you’re ha Jan 18, 2013 · possibilities, fuel line, filter, CP3 pump. i have a 1990 f350. The fuel tube out of the tank goes under the cab to a rectangular block. After that it runs fine. Jan 24, 2018 · Here’s the link: Fuel Pressure Tester. You will start to see fuel leaking out the top of the Minder Switch. I believe the fuel system is losing pressure after Jul 16, 2013 · On the fuel pressure tester I purchased the instructions actually stated something to the effect of "If the system holds pressure within 2 psi for 10 minutes after key is off then no leak. I am having to prime the fuel lines with the key in the on position 2-3 times. Feb 20, 2023 · The fuel pressure regulator controls the fuel pressure in the fuel rail. You are likely to be sucking air on ur fuel line. my rail pressure is somewhat low, but overall performance and fuel mileage is still as good as ever. POSSIBLE CAUSES Is it normal for the fuel pressure win the fuel rail to bleed down after 30 minutes or so. Other than o-rings or leaky lines or fittings, you can lose pressure only 3 different ways. Feb 1, 2024 · This summer after sitting for extended periods of time, car wouldn't start unless I'd pump the accelerator pedal. Oct 26, 2022 · 3. Time to troubleshoot a spring no-start. From watching the gauge, anytime I attempt to give it throttle, I can see the pressure drop from 32 to 2 or 3 psi. I bought one of the permanent mount fuel pressure gauges and installed it on the output side of the fuel filter, which is mounted on the firewall. If your engine is in fact 'fuel starved' after sitting for some period of time then the problem is that the fuel bowl(s) are draining - either into the intake manifold, back to the pump/tank, or externally. If you don’t have access to a scanner, the fuel pressure can also be measured with a fuel pressure gauge. Truck sat for about a year after upgrades were done, now if it sits for 24 hours or more it has an extended crank while waiting for low pressure oil to reprime. I really don't know what's left to replace, but is it possible the injectors are leaking internally causing fuel pressure loss? Mar 28, 2011 · Most likely it's not a fuel problem. If it holds pressure till the fuel filter, whatever the issue is after the filter. 2 gas engine and have been having problems starting it recently. The engine runs flawlessly once started, which is why I haven't been in a hurry to address the issue. The fuel pressure regulator doesn’t fail very often, but it is still worth checking to see if it might be causing your problem. Dec 31, 2017 · Well I've tried everything I can think of and still no luck. If the engine has been turned off for any length of time, the engine just turns over and over and either barely starts, or doesn't start at all. With the key ON, engine OFF, my pressure does not build unless I cycle the key on and off and even then it only builds about 5-10psi at a time, but does not drop rapidly. Fuel pressure on a return type fuel Dec 30, 2017 · I have 2 fuel pressure gauges to view inside my cab. Feb 20, 2006 · So i have an 01 lb7 with everything stock past few mornings i have had to prime the truck. Jan 19, 2017 · Buy Duramax Fuel Filter Housing 1) Install fuel vacuum test tool. May 28, 2017 · • Little or no fuel pressure at the fuel rail test valve similar to this - 1- Key in on position; fuel pump primes for 2 seconds then stops. Gasket® - Fuel Pressure Gauge Adapter) Or maybe even a permanent fuel pressure gauge? Nov 30, 2014 · Check your primer button after sitting for a while/overnight, see how many pumps it takes 'till hard. 5 bar for gasoline fuel) is what ensures the atomization of fuel in the engine combustion chamber. Nov 28, 2005 · your fuel pressure is maintained by the pressure regulator to hold. A description of the fuel system is as follows. I have a problem with my toyota losing fuel pressure after sitting for 10 hours or more. From what I read on this forum, as long as you don't have rapid bleed down, meaning you go from 40psi to 10psi in less than an hour, you should be OK. Seems like it has little loss of prime whenever I have a full or nearly full tank of fuel. After the car had sat all night, the pressure was 0 PSI. < 5 PSI 4- Engine idles and fuel pressure creeps up to 45-50 PSI. In replacing the filter head, be sure to source the newer style ($100) vs your old style ($485), and replace/lengthen the two fuel lines to it with a quality bio-compatible 1/2" fuel line. 4. But it's probably the hose. This demonstrated that there was no leak back that would bleed off pressure. Mar 27, 2019 · **This video specifically addresses problems with aftermarket fuel systems and does not necessarily represent problems with a stock fuel system. This pressure (usually 2. Jun 12, 2021 · If you haven't already, you may want the dealer to perform TSB # 18-031-17B before testing fuel pressure leakdown. At that age, all fuel hoses should be replaced. A couple of year laters same weird hesitation,crank issue started occuring, threw in the towel. 2) Prime the fuel system with the hand primer until 10 PSI is indicated on the gauge, check for external leaks and repair. It opens at a certain predefined pressure and leaks the excess fuel flow or pressure back to the fuel tank. Stuck Fuel Injector Jan 20, 2019 · I thought that my fuel pressure may had been bleeding off into my return line or back through the check valve in the fuel pump. I replaced return lines, caps, and fuel filter. ⇒ If the engine does not start or the fuel pressure is less than 145 MPa when commanded, replace the fuel injection pump. thanks Feb 13, 2016 · I had my fuel filters changed at the dealership today on my '15, and then I bought fuel and headed home (70 miles). I’m having some rough start issues after installing a cold air intake, adjusting valve clearance, replacing plugs and wires, replacing IAC, replacing fuel filter and injectors. The one to the right of my CTS2 reads fuel psi off my liftpump. Clamp off the feed line, and wait a few hours to see if it loses pressure. Shop for New Auto Parts at 1AAuto. Old fuel lines will leak at the connections Jan 17, 2005 · What would cause a loss of fuel pressure after the car sits for a day? I have a new 255 fuel pump I installed in November. I recently replaced the fuel pump with oem acdelco, fuel filter, fpr. it is cold enough for snow to stay. After a few hours the fuel pressure was at 0. So i'm really at a loss for what's happening, why it takes so many squeezes of the bulb. The pressure should stay at 40-50 psi but does not. Possible soulutions and reason for truck to be losing oil prime on low side? Mar 9, 2016 · Turned out there are 4 formed rubber fuel lines after the fuel filter that were all dry rotted. Deadhead the pump and see if it will hold pressure. On cold mornings my engine stars immediately with no hesitation, even though it is beginning with no fuel pressure. Still has the same symptoms. Parking downhill and starting will point out air leak especially in return system. The fuel pressure should be able to reach 145 MPa when commanded. I’m right under 50# when running. circulated the fuel pump 2-3 times to see if it helped, not so much. From what the mechanic has said, if i am understanding this correctly, when the truck sits overnight, in the morning it has to crank and crank until it gets fuel. Feb 18, 2012 · I agree with above posts. He didnt give me much details, just that it doesnt have the pressure it should. all had the LBZ engine. But I can tell you it’s definitely loosing fuel pressure at higher Rpms because the truck doesn’t roll any coal above 2300 rpm. I have a hard time starting up right afterwards. Is there another check valve some where that may be causing this? It only happens after motor has been off for a while. Oct 18, 2016 · After starting and running the engine for a few minutes, pinch off - but not quite completely- the fuel supply and see if that causes a problem. Not sure if that was at wide open throttle or nt. : 2004 Chevy Tahoe Z-71, 5. 5 posts • Page 1 of 1. If I turn the key and hold it for like 6 seconds of cranking it won't start, but if I crank it a few separate times for only a few seconds it will start up. Start by keeping steady pressure on the primer bulb and carefuully inspecting the system all the way to the engine. If you cycle the key on/off a couple times for a few seconds each it will prime the fuel system. But it didnt fix the issue. May 25, 2011 · Yes check valve in the pump can go bad and cause quick pressure loss. . I’m troubleshooting my 2015 lml, died on the side of the road low rail pressure P128e and the change fuel filter message. I can drive it for a long time, turn it off, and it starts right back up. i do not notice any fuel smell or a leak anywhere. First thing I tried was removing 3 glow plugs and trying to bleed trapped air. The occasional idle stutter in traffic makes me think it loses pressure pretty quick. Nov 26, 2016 · Should the truck lose fuel pressure once it sits for the night? Last night turned truck off with 49 psi on guage. or so. Sep 30, 2016 · Q: Hi goodnight So lets start after driving my car for like 30 mins my fuel pressure drops causing the car to misfire and move slugish I rewired and changed my fuel pump but same issue Im using a tomei fpr,can it be faulty? Apr 23, 2023 · Truck has newer injectors and upgraded turbo, t500 hpop. Car is stored for winter, but would like to figure out in case Oct 17, 2010 · High fuel pressure during cranking will cause hard start. 2L - Hey guys, dealing with an ongoing issue with 2 dealerships that refuse to honor their warranty on my truck. Pressure should be 117-152 kPa (17-22 psi) at idle speed. Pressure regulator could be stuck open draining fuel back via return pipe. 2 Starting Problems - I have a 2011 F-250 with the 6. Oct 26, 2017 · Originally my truck was losing fuel pressure after sitting for a while; for example I would get in my truck in the morning start it up pull out of the driveway and the rail pressure would drop down, I'd lose power, and the truck would run ruff but the truck never stalled and if I let off the throttle and got back into it the truck would run fine. Nov 17, 2015 · We have replaced fuel filter housing and lines around it. A minimum of 172 kPa (25 psi) should be indicated after raising engine speed to its rated rpm (2,500 rpm) with no load. We have replaced the cp3 ?, the injectors have been tested by 2 different diesel shops. ive replaced the manual fuel pump and it started fine for about 3 weeks. im guessing the problem is between the manual pump to the Oct 14, 2019 · I do know it has brand new BD injectors and a brand new Fleece 750 CP3, as well as the high pressure fuel lines from the rail to the tubes all brand new. Find out the common causes, such as leaking fuel injectors, faulty fuel pump, clogged fuel filter, vapor lock, and bad fuel pressure regulator. Mar 29, 2009 · The pressure drains away after a few minutes through the fuel return line which is perfectly normal. In addition, fuel pumps will usually go bad from sitting overnight. Injectors can be checked by pulling the fuel rail off with injectors and electrical connections attached, priming, BUT DO NOT CRANK the engine, and visually May 13, 2012 · I have a 2005 Chevy Silverado 1500 and I lose pressure gradually when I shut off the engine. I'm pretty sure it's losing prime because if you cycle the fuel pump with the key 3 complete cycles it will fire right up. i also read that I could be losing it from pressure gauge I have also which Sep 26, 2022 · I’ve got a 350 SBC with a Holley Sniper system in my 80 series Land Cruiser. Did it at 12 degrees out on a cold start, then 3 days later at 60 degrees after sitting two hours and today at 50 degrees after sitting an hour. 4 Fuel Pressure Issue FYI - About a month and a half ago I set out on a business trip in my 09 Lariat SCREW with 5. I don’t currently have a fuel pressure gauge in but am going to do that soon. First pinch off the fuel return hose where it is rubber between the fuel rail and the body. I’m running a return style system that almost perfectly mimics the factory fueling system in a stock 80. Its pretty easy to diagnose. In contrast, most carbureted cars have, or originally had, a mechanical fuel pump, and after sitting all winter they often give us trouble. The car is getting hard to start after sitting all week. I will also check the oil level. Gasket Part Number:400200-BL more details on - Mr. It will still start, but it takes a while. 5 to 3. I charge the battery once a month so I don't lose charge. Apr 21, 2014 · I have a 02 impala 3. Is your davco bowl empty or can you see fuel? If it’s empty then remove the top cap and make sure there’s an o-ring there. At high altitude especially I’m constantly losing fuel pressure. I have replaced fuel/h20 separator and primer bulb with no luck. A week later, it had 39 PSI. The fuel system loses pressure with the truck off. Oct 19, 2006 · I always lose my fuel prime if I let the truck sit for more than a few hours. Sep 18, 2015 · 2009 - 2014 F150 - 2009 5. About half way home I got a "Low Fuel Pressure" message and a little while after that "Reduced Engine Power" along with the check engine light. Oct 6, 2020 · 2009 - 2014 Ford F150 - 2013 EB Fuel Pressure - Started having an issue with long or extended crank for the truck to start on cold start ups. When I put a fuel pressure tester in the line after the filter and before the fuel rail, I get reading of 36-38 psi. May 11, 2024 · However, a fuel pump going bad after a car has been sitting is a common culprit. The other half of the time it turns over immediately. The pressure should read steady at 70psi. You most cost effective route for the long run would be to convert to e-fuel. Jeep is now having the same hard start problem as before. Sep 7, 2005 · If I turn the key on/off several times to activate the fuel pump, it will start up and run normally. Jun 30, 2014 · I have an 03 f450 that's losing its fuel prime after sitting for over 6-8 hrs once started it runs and starts great all day. Mar 16, 2021 · Fuel pump died just over a year ago, replaced pump runs great for 1 week then I get hard starts check fuel pressure and it drops to zero in about 30 seconds so I replace pump works fine for about a year then get a hard start a few times till now its all the time, I check pressure and it drops to zero in about 30 seconds after key is turned off. If the pressure drops from 10 PSI to 2 PSI in less than 1 minute, remove the fuel outlet line from the filter and cap it. Checking the injectors is a pretty easy step to do and it should only take a few minutes to check. If you want to check regulator, pinch a section of the return fuel where its soft rubber. I've replaced everything mentioned above and it's still doing the same thing. 2-3 PSI 3- Engine starts and idles for 20 seconds. You can try crimping the fuel return line to pressure the lines. He said his rail pressure is around 17,000. Runs and drives fine once started. Whether its an injector leaking, a bad fuel cross tube seal, a FCA, or rail pressure sensor, CP3. Once running, drives and starts fine. What's happening is after sitting for a while, I lose the prime. you should get proper furel pressure almost immediatly after you start to crank the Jun 2, 2007 · 6. Jun 7, 2010 · Re: 99 johnson 115 outboard losing fuel pressure after sitting I would say that you have an air leak in your system and possibly some obstruction as well. It started when the truck sat overnight, now the issue starts earlier, even as much as 4 hours. Back in the driveway and see if you have fuel in the upper filter after it sits. Jul 24, 2017 · 1995 f-150 xlt 5. I have an extended crank issue that I believe to be a bad check valve in the fuel pump, but the dealer refuses to look any further at it because they have been Jul 23, 2023 · When that happens, the car will not start because it doesn't have enough fuel pressure to get going. No need for a gauge, cause when I loosen the front banjo bolt on the fuel rail there is no gas. Jan 8, 2012 · I am at the end of my rope with this truck one day it wants to run amazing the next day it doesn't. Use a fuel pressure gauge to test the path of fuel. This is ideal. the lift pump took care of losing prime and no more p0087 codes. Once it finally starts, then it is fine. The system was loaded up with air so I made up an auxiliary tank to the inlet of the filter housing, primer pumps hard after 4-5 pushes. Weird May 22, 2018 · Fuel is coming out of somewhere it shouldn't be. Mar 30, 2014 · Once pressure is achieve, close the inlet shutoff valve and monitor the pressure on the gauge. it bleeds off very slow after I put new pump in. Fuel pressure at 60 psi sitting, cranking/running just under 60 psi. Jun 4, 2010 · It has a diaphram that is linked to the intake manifold with a vacuum line so the the pressure drop across the injector is always the same regardless of the pressure in the intake manifold. i used a fuel pressure tester anyways. Jul 25, 2020 · Initial start-up with 32psi at idle and 42 psi of pressure with the vacuum hose off of the regulator. Oct 22, 2023 · Around the same time in 2016 i replaced the fuel pump with a OEM delphi because i suspected/tested loss of pressure after sitting. When I shut it off, it had 40 PSI. Feb 18, 2016 · I had a 1901 Steet Demon and did not have this issue. Didn't appear to have an effect. Aug 17, 2019 · I've got a 2015 D13 and I'm losing fuel prime completely randomly. Everything i research says bad injector but I don't know which one. Sit for more than a few hours and it doesn't want to start. I am using a cheap rail gauge. Mar 31, 2014 · The first time I hammer on it for the day (EDIT: not just the first of just the day, let's say the first time after an hour of sitting), fuel rail pressure jumps to 26,000 for about 2-3 seconds, but then falls off to 10,000 or les and won't come back up. I went back over all of the hoses that I pulled off and then reinstalled during Jan 8, 2016 · I'd bet on the fuel pressure regulator. Jun 8, 2020 · Looking for some input. Jun 9, 2014 · I replaced the rubber fuel lines, injection pump, and lift pump. I am assuming I need to check the return line that goes from the back side of the engine to the tank. And they do hold pressure for quite a while. Then check after the filter (so pressure gauge deadheads the fuel filter outlet). The fuel filter is replaced every 7k to 8k miles (every oil change). Just yesterday I laid under truck near fuel tank and did notice a leak where soft line coming from fuel sending unit connects to Jul 16, 2013 · My last fuel filter change was a while ago, so I will do that this morning to rule the filter out as a cause. I took off the air intake tube. A leak any where (especially return) will allow air to leak into line and fuel to siphon back to tank. If that fails, pressure will drop. I have a 2020 f150 supercrew FX4 3. I'm thinking maybe i have a leak at the fuel filter head, or the plastic bleeder screw. First at the pump to check it's not bleeding back. Once the fuel pressure gauge is hooked up, cycle the ignition key on and off a few times to build fuel pressure in the system. it used to a little, now nothing. Two things can happen. Dec 12, 2020 · Percolation – Percolation can happen when your engine gets hot, then you turn the engine off and the fuel boils over, sometimes over the top of the carburetor, or more often, simply evaporates. Apr 12, 2020 · I hadn't been able to get to my car in about 2 weeks and when I tried to start it yesterday, 0 fuel pressure. The idea is that you would emulate a restricted fuel supply issue (think collapsed temp fuel line collapse near the trans or by the top driver side of the engine) and that restriction might cause the Nov 13, 2010 · To me it sounds like you are having a problem creating the pressure needing to start the engine. A really good test to see where you are losing prime is to take a low pressure regulator and put about 3-5 psi pressure on your fuel tank. 99 f250 7. Check valve Jan 28, 2017 · Fuel pressure on a return type fuel system can leak one of three places. morning had no psi. Sep 8, 2005 · 2003 GMC Sierra 2500HD SLE: 4WD, Crew Cab, Short Bed, Duramax/Allison, Silver . 3 idi in my 88 f350 and I got it runnin and all but it loses fuel pressure overnight after an extended period of time. Jun 25, 2009 · my jeep seems to be losing fuel pressure over night. 4. Hence long crank times. 3, V8 311,000 miles, leaks oil now at rear main seal stock 4L60E on 5th filter/fluid change; 2nd set of drive shaft u-joints; rear diff new bearings; 2nd fuel pump and fpr; ABS pump circuit solder reflowed; 4th water pump; 2nd fan clutch; new front wheel bearing units; new front and rear shocks; 1000# rear air springs, Brake fluid Oct 16, 2008 · Try taking the vacuum line off the regulator and smelling it. I have to go under the hood and pump up my diesel fuel system - located on the passenger side of the engine. I am running a Holley Dec 19, 2016 · Test the fuel pressure using the correct procedure, KOEO (key on, engine off). If there’s not then that’s your problem, if there is one there then remove the lower ring and make sure the o-ring on the plastic bowl isn’t pinched and is seated properly at the bottom and not in between the ring and bowl. Replaced sending unit, fuel cooler, and lines to underneath front door. I would rather not replace all injectors since that is big $$ May 12, 2017 · 2012 MP8, low fuel pressure, replaced fuel pump, flushed lines , still have 5-6 psi at idle, I have read in forum about regulator in front of head , to which Mack can't locate. could it be related to the fuel filter? no one seems to know. You're losing pressure very quickly, and your pump isn't running when it should be. Now I have good strong fuel pressure when running but as soon as the engine shuts off it drops to nothing. It took some cranking after sitting for 5 months but that's normal. I replaced the camshaft sensor and cleared the code but the check engine light won't go off and the cruise control is not working either. If it bleeds down over the next few minutes (20), you have a leak on the engine side fuel system. Oct 16, 2017 · The big mistake most folks do is to not replace those fuel lines when rebuilding the primer head. I'd be surprised if it's leaking so I have to assume the fuel is just evaporating quickly. has a look at a Cadillac that will not hold fuel pressure. fixes, replace fuel line, replace filter, or add a lift pump and that will fix the problem. What could be the problem or Jan 24, 2013 · Loss of fuel pressure is either the check valve/regulator on top of the pump or a leaky injector. The Fuel filter Minder Switch is located underneath the tube. Mar 6, 2015 · I am apparently losing prime when sitting. 7. Apr 27, 2020 · General F150 Discussion - 1999 F150 4. If you want a cure for the problem try running an electric pump. I tested the fuel pressure after it sat 10 hours, the gauge slowly moved from 0 to 30 psi, thats when the moter finaly started, and then the pressure continued to rise to 50 psi where it stayed stable. Jun 1, 2018 · Since you already have a pressure gauge, you can test and figure out exactly which one. Jan 21, 2019 · 0 pressure after an extended period of time sitting like overnight is normal according to the Mopar factory service manual. The car won't start if it had been sitting a while I bought a fuel pressure gauge and tested the pressure this morning. To an extent pressure loss is okay. A 1/4" ratchet, 10mm deep socket and maybe an extension is all you need, optional tools would be a fuel line quick connect release tool and small Aug 25, 2019 · after sitting, Starter continues to turn over and doesn't start? after second attempt, it does start rough. rubyb ehkfn vwxzj lhzrkg erazcb lhnn frs aaxhtec fcbz misfrtx