Fuel pump prob!?!?
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From: Macclenny Florida
Fuel pump prob!?!? OK....so I have been chasing a high rpm stumble for the past month or so...
Replaced
Opti
Coil
ICM
Plugs
Wires
Knock Sensor
Opti Harness
and nothing has fixed it...
Today I go out and turn the key and the fuel pump primes and as SOON as it quits my Autometer fuel pressure gauge falls to 10psi almost instantly...
I know the regulator is good as I just replaced it a week ago because I was getting fuel through the vac line....
So I am guessing the fuel pump is bad now???
The car is almost on Empty for fuel would that have anything to do with it? You think this could have anything to do with my high rpm stumble??
Replaced
Opti
Coil
ICM
Plugs
Wires
Knock Sensor
Opti Harness
and nothing has fixed it...
Today I go out and turn the key and the fuel pump primes and as SOON as it quits my Autometer fuel pressure gauge falls to 10psi almost instantly...
I know the regulator is good as I just replaced it a week ago because I was getting fuel through the vac line....
So I am guessing the fuel pump is bad now???
The car is almost on Empty for fuel would that have anything to do with it? You think this could have anything to do with my high rpm stumble??
Thread Starter
9 Second Club
iTrader: (35)
Joined: Feb 2009
Posts: 1,542
Likes: 2
From: Macclenny Florida
I don't know if its a stock pump the guy before me may have changed it...
I have a Autometer gauge on it and it reads 40 at idle and 45 at wot...however when I turn the key and don't start the car it drops back down very fast....
I sent you a PM about the racetronix....
Thanks
Matt
I have a Autometer gauge on it and it reads 40 at idle and 45 at wot...however when I turn the key and don't start the car it drops back down very fast....
I sent you a PM about the racetronix....
Thanks
Matt
I don't know if its a stock pump the guy before me may have changed it...
I have a Autometer gauge on it and it reads 40 at idle and 45 at wot...however when I turn the key and don't start the car it drops back down very fast....
I sent you a PM about the racetronix....
Thanks
Matt
I have a Autometer gauge on it and it reads 40 at idle and 45 at wot...however when I turn the key and don't start the car it drops back down very fast....
I sent you a PM about the racetronix....
Thanks
Matt
-Leaking fuel pump check ball.
-Leaking fuel pump flex pipe.
-Leaking valve/seat within fuel pressure regulator.
-Leaking injectors.
The injectors are easy enough to test - just remove the four bolts holding the regulator down, lift off the fuel rail, pressurize the fuel system, and see if any of them leak.
The regulator can be tested by either a.) removing the vacuum line and smelling/feeling for fuel or b.) applying vacuum to the regulator and seeing if fuel pressure changes.
If one of those two isn't the case, then you've got an issue in the tank.
Thread Starter
9 Second Club
iTrader: (35)
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From: Macclenny Florida
Pressure leaking down at idle that fast can only be caused by one of four things:
-Leaking fuel pump check ball.
-Leaking fuel pump flex pipe.
-Leaking valve/seat within fuel pressure regulator.
-Leaking injectors.
The injectors are easy enough to test - just remove the four bolts holding the regulator down, lift off the fuel rail, pressurize the fuel system, and see if any of them leak.
The regulator can be tested by either a.) removing the vacuum line and smelling/feeling for fuel or b.) applying vacuum to the regulator and seeing if fuel pressure changes.
If one of those two isn't the case, then you've got an issue in the tank.
-Leaking fuel pump check ball.
-Leaking fuel pump flex pipe.
-Leaking valve/seat within fuel pressure regulator.
-Leaking injectors.
The injectors are easy enough to test - just remove the four bolts holding the regulator down, lift off the fuel rail, pressurize the fuel system, and see if any of them leak.
The regulator can be tested by either a.) removing the vacuum line and smelling/feeling for fuel or b.) applying vacuum to the regulator and seeing if fuel pressure changes.
If one of those two isn't the case, then you've got an issue in the tank.
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From: Macclenny Florida
If I pull the rail up and pressurize the system it won't push the injectors out of the rail?
is it pretty rare to have a leaky injector??
I know the pump is pretty old so I am thinking that may be the prob but of course I will check everything before I throw money at it...
The regulator and I have rechecked it so its either the pump or injector....Car has been a bit hard to start lately too....
with the car running the pressure is great...so if it just leaks down after shutoff then what kind of problems can it cause???
Matt
No, the injectors won't go anywhere (they're held in with clips, and the friction of the o-rings will keep them seated).
Leaky injectors are not unheard of, and it's easy enough to check.
Leaky injectors are not unheard of, and it's easy enough to check.
Thread Starter
9 Second Club
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From: Macclenny Florida
injectors looked good...just got done doing it...
So it has to be something in the pump....Gonna order a new one this week..
Now my questions is if it has good pressure during idle and WOT what will it hurt to drive until the new pump comes in?
Matt
So it has to be something in the pump....Gonna order a new one this week..
Now my questions is if it has good pressure during idle and WOT what will it hurt to drive until the new pump comes in?
Matt
