Low fuel pressure.. ??
09-26-2008, 10:47 AM
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Low fuel pressure.. ?? Howdy. I checked my fuel pressure (have a mechanical pressure checker hooked up to car right now) and at idle it shows 20psi, and when I give it gas, it drops pressure. The pump is brand new (was doing this with the last pump as well), and the fuel filter is brand new. Any ideas on what it could be?
09-26-2008, 11:04 AM
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I just changed the filter. Pump is a holley 190lph. Previous pump was a holley 255lph. I have a feeling the other pump wasnt bad at all. Stupid mechanic told me it was the pump, so me being in a rush bought another and changed it, but to no avail. Can the FPR affect pressure even though its after the schrader valve?
09-26-2008, 11:13 AM
#5
The way this works is you have your incoming line going into the fuel rails. It runs through the passenger side rail, through the crossover and into the drivers side rail, and through the driver's side rail. The regulator is on the end of the driver's side rail. It is the last step. It holds a certain pressure and lets excess fuel by as needed to maintain the desired pressure. The schrader valve is on the incoming line, so yes the schrader valve is what allows you to monitor the pressure at the rails, not the feed line circuit
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09-26-2008, 05:45 PM
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The way this works is you have your incoming line going into the fuel rails. It runs through the passenger side rail, through the crossover and into the drivers side rail, and through the driver's side rail. The regulator is on the end of the driver's side rail. It is the last step. It holds a certain pressure and lets excess fuel by as needed to maintain the desired pressure. The schrader valve is on the incoming line, so yes the schrader valve is what allows you to monitor the pressure at the rails, not the feed line circuit
09-26-2008, 06:02 PM
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You're just a ray of sunshine 
I also pride myself on my keen deduction skills!! 
Seeing as he had no idea about what was causing this, I figured I'd help him out by explaining how the FPR was doing what it's doing.
So there's no need to be an asshat, just because of that other thread.
I also pride myself on my keen deduction skills!! Seeing as he had no idea about what was causing this, I figured I'd help him out by explaining how the FPR was doing what it's doing.
So there's no need to be an asshat, just because of that other thread.
09-26-2008, 10:57 PM
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OMG it was the stupidest problem ever. I had a mechanic do the pump (due to no time on my end) and that is the last time i let a mechanic touch my car. I took the pump out to see if anything is wrong with it, and the fuel feed lines (going from the pump to the motor) werent clamped down on the pump, therfore allowing fuel to pour out, back into the tank hahahah wow..
09-26-2008, 11:31 PM
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And spread the word around public of he awesomeness as well. He shouldn't be allowed to touch anyones car, not just yours! Ok, maybe the occasional overly cocky Mudstain owner.... which I guess would be all of them then >_>
09-27-2008, 11:27 AM
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OMG it was the stupidest problem ever. I had a mechanic do the pump (due to no time on my end) and that is the last time i let a mechanic touch my car. I took the pump out to see if anything is wrong with it, and the fuel feed lines (going from the pump to the motor) werent clamped down on the pump, therfore allowing fuel to pour out, back into the tank hahahah wow..
09-27-2008, 06:17 PM
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Well a day late but thats EXACTLY what i was going to tell you to check, this happened to me & drove me crazy, you also need to make sure (if you've changed that feed line in the tank) NOT to run the EFI rubber hose, it will swell up & pressure will drop, i now run a steel braided hose & all is good, glad you got it fixed.
