Need help on fuel pressure problem.
Thread Starter
Melting Slicks
Joined: Sep 2004
Posts: 3,287
Likes: 1
From: Union City CA
Need help on fuel pressure problem.
Hi, I have posted this on the Tech section also.
I am going to my tuner to find out why my pressure is dropping. The fuel pump was tested and was in the acceptable range.
My fuel pressure gauge was also tested and found to be accurate.
The pressure would start about 70-71psi (I know that 70 psi is high but that is what it shows) when the engine is cold then it would just start to drop slowly as the engine warms up. After about 15 minutes at idle, the fuel pressure would start at about 70 psi and then drop to about 60 psi. I was told that the fuel pump pressure is good as long as the fuel pressure is above 55 psi.
I am going to add a boost a pump later but just want to see if anyone out there knows the cause of this problem and whether a boost a pump is the fix.
The problem started after the car was parked for about 4 weeks.
Someone was telling me that maybe the fuel filter was clogged by junk that had sat in the bottom of the fuel tank, gotten sucked up and clogged the fuel filter. However this would not explain why the pressure would drop when hot. Wouldn't the pressure be low the whole time regardless of heat?
Any help would be greatly appreciated.
I am going to my tuner to find out why my pressure is dropping. The fuel pump was tested and was in the acceptable range.
My fuel pressure gauge was also tested and found to be accurate.
The pressure would start about 70-71psi (I know that 70 psi is high but that is what it shows) when the engine is cold then it would just start to drop slowly as the engine warms up. After about 15 minutes at idle, the fuel pressure would start at about 70 psi and then drop to about 60 psi. I was told that the fuel pump pressure is good as long as the fuel pressure is above 55 psi.
I am going to add a boost a pump later but just want to see if anyone out there knows the cause of this problem and whether a boost a pump is the fix.
The problem started after the car was parked for about 4 weeks.
Someone was telling me that maybe the fuel filter was clogged by junk that had sat in the bottom of the fuel tank, gotten sucked up and clogged the fuel filter. However this would not explain why the pressure would drop when hot. Wouldn't the pressure be low the whole time regardless of heat?
Any help would be greatly appreciated.
Race Director
Joined: Oct 2005
Posts: 14,555
Likes: 1,255
From: Saint Albans, WV
I would think the filter "could" be a problem. Is it possible to have someting moving back and forth in the filter causing flow issues?? Is it posssible you have a low voltage problem?? Seems that if your car has had proper fuel pressure then all of a sudden it changes, unless you have a blower, a BAP should not be necessary and may do nothing but mask your real problem. Good luck.
Thread Starter
Melting Slicks
Joined: Sep 2004
Posts: 3,287
Likes: 1
From: Union City CA
I would think the filter "could" be a problem. Is it possible to have someting moving back and forth in the filter causing flow issues?? Is it posssible you have a low voltage problem?? Seems that if your car has had proper fuel pressure then all of a sudden it changes, unless you have a blower, a BAP should not be necessary and may do nothing but mask your real problem. Good luck.
Just don't know why the sudden fuel pressure drop after the engine is hot now.
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Good luck
Thread Starter
Melting Slicks
Joined: Sep 2004
Posts: 3,287
Likes: 1
From: Union City CA
You need to get the guage checked , check the fuel pressure at the rail - I have been doing research myself for my own car , and 70Psi on the stock pump is not possible , so your initial reading is not good . Sounds to me like your gauge is the problem .
Good luck
Good luck
