93 fuel pressure problem
Thread Starter
Racer
Joined: Mar 2017
Posts: 305
Likes: 14
From: Canfield Ohio
93 fuel pressure problem
my pump turns on for about three seconds when key turned to on.
when starting car fp is about 38 psi but as soon as I shut off car fp drops immediately.
I have a miss that occurs when the car has started and run for about half a minute. Opti, plugs injectors all good thinking I may have FP Regulator going bad.
Any thoughts?
when starting car fp is about 38 psi but as soon as I shut off car fp drops immediately.
I have a miss that occurs when the car has started and run for about half a minute. Opti, plugs injectors all good thinking I may have FP Regulator going bad.
Any thoughts?
Race Director
Joined: Sep 2001
Posts: 14,682
Likes: 753
From: NEwhere Ohio
my pump turns on for about three seconds when key turned to on.
when starting car fp is about 38 psi but as soon as I shut off car fp drops immediately.
I have a miss that occurs when the car has started and run for about half a minute. Opti, plugs injectors all good thinking I may have FP Regulator going bad.
Any thoughts?
when starting car fp is about 38 psi but as soon as I shut off car fp drops immediately.
I have a miss that occurs when the car has started and run for about half a minute. Opti, plugs injectors all good thinking I may have FP Regulator going bad.
Any thoughts?
in my case, there was a leak in the fuel pump discharge to the outlet pipe on the fuel tank sender unit
there is a coupler and , even though i had a hose clamp, the top end of the coupler was leaking where it joins the pipe. A mity vac confirmed this when i took it apar
an extra hose clamp did the trick
this problem would make the car hard to crank, esp when hot.
Note i dont have a stock fuel pump on mine. Wabro 450 l/hr
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
my pump turns on for about three seconds when key turned to on.
when starting car fp is about 38 psi but as soon as I shut off car fp drops immediately.
I have a miss that occurs when the car has started and run for about half a minute. Opti, plugs injectors all good thinking I may have FP Regulator going bad.
Any thoughts?
when starting car fp is about 38 psi but as soon as I shut off car fp drops immediately.
I have a miss that occurs when the car has started and run for about half a minute. Opti, plugs injectors all good thinking I may have FP Regulator going bad.
Any thoughts?
Fuel pressure after you shut your car off can be an indication of some things, but usually not a big deal. Running Fuel Pressure is what matters. Some new pumps are centrifugal and don't use a check valve. To truly isolate your issue you have to crimp the return and feed lines and isolate components. Even if the fuel system can drain back on the feed side, if you still have good pressure while its running it will run fine.
As suggested above, finding a method to observe fuel pressure while driving is ideal.
If your FPR is bad, you should be getting fuel into the vacuum hose and into the manifold. Do you have a rich condition or smell gas if you pull the vacuum line off? A fuel pressure regulator is probably not causing a miss, it usually causes poor operation across the board.
Last edited by KyleF; Sep 30, 2020 at 08:26 AM.
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
i just solved this problem on my 93.
in my case, there was a leak in the fuel pump discharge to the outlet pipe on the fuel tank sender unit
there is a coupler and , even though i had a hose clamp, the top end of the coupler was leaking where it joins the pipe. A mity vac confirmed this when i took it apar
an extra hose clamp did the trick
this problem would make the car hard to crank, esp when hot.
Note i dont have a stock fuel pump on mine. Wabro 450 l/hr
in my case, there was a leak in the fuel pump discharge to the outlet pipe on the fuel tank sender unit
there is a coupler and , even though i had a hose clamp, the top end of the coupler was leaking where it joins the pipe. A mity vac confirmed this when i took it apar
an extra hose clamp did the trick
this problem would make the car hard to crank, esp when hot.
Note i dont have a stock fuel pump on mine. Wabro 450 l/hr
Thread Starter
Racer
Joined: Mar 2017
Posts: 305
Likes: 14
From: Canfield Ohio
FPR is bad replaced holds pressure and runs fine until you move the car then it misses.
My buddy the mechanic thinks it's a ground issue. Have gone over the electrical end of things..Plugs, wires, Injectors and a new alternator this is after verifying before replacing parts. This is a real lemon worse corvette I've had.
My buddy the mechanic thinks it's a ground issue. Have gone over the electrical end of things..Plugs, wires, Injectors and a new alternator this is after verifying before replacing parts. This is a real lemon worse corvette I've had.
