Hard Start and Fuel Pressure problems
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Joined: Feb 2023
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From: North Carolina
Hard Start and Fuel Pressure problems
A bit of background on the car (1995) - I've had it a few months and at first it ran rough. Mechanic said I had a leaking fuel injector, but I discovered the FPR was bad and replaced it which got it running ok. Later I removed all of the fuel injectors (they had been upgraded to Bosch 3s) cleaned them with a cleaning kit that sprays carb cleaner through them and they were spraying fine, replaced the O rings and reinstalled. It's been running fine for several weeks, but this weekend I took it on a long drive and went in the store and when I came back, it didn't want to start, started for a second and cut off. But then I was able to get it started. Same thing happened several times, engine was cranking but it didn't want to start.
Today I hooked up a fuel pressure gauge and made the following observations:
Upon turning the key to on, FP jumps to 50, then immediately drops to 0
When car is running, pressure steady around 50
When shutting off the car, pressure drops to 0 immediately
So I think this indicates a leak somewhere. Could it be the injectors again, or something else?
Today I hooked up a fuel pressure gauge and made the following observations:
Upon turning the key to on, FP jumps to 50, then immediately drops to 0
When car is running, pressure steady around 50
When shutting off the car, pressure drops to 0 immediately
So I think this indicates a leak somewhere. Could it be the injectors again, or something else?
Last edited by ThinLizzy; Jun 12, 2023 at 06:10 PM.
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Joined: Dec 2017
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From: Omaha, NE
It could be the check valve in the fuel pump. Remove the cover on the gas tank. Turn on the key, then pinch off the return line. You will need a helper. If it loses pressure then its the fuel pump check valve.
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Joined: Feb 2023
Posts: 68
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From: North Carolina
Thread Starter
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Joined: Feb 2023
Posts: 68
Likes: 5
From: North Carolina
Well that was the right direction. Found a rubber hose running from fuel pump to metal line had a crack in it so I replaced it.
Pressure is holding but now I have a different problem - when running the fuel pressure stays at 80psi
Pressure is holding but now I have a different problem - when running the fuel pressure stays at 80psi
Instructor
Joined: May 2023
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yeah i had the same peoblem, trew parts in it like crazy (3000$) and turns out fuel filter pump inside the tank and under the car, changed Them both and fuel pump at the same time and clean the tank and bang sovled everything.
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Joined: Feb 2023
Posts: 68
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From: North Carolina
Thanks to everyone who chimed in. I found a restriction in the metal return line on the fuel sending unit. Fuel pressure is holding (the needle does very slowly drop over time) and maintains at 30psi which I think is a little bit below where it should be, but I'll see how it drives once it stops raining.
