GSL-SE Fuel Pressure Question
07-17-14, 08:48 AM
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1st Gens are the Best
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GSL-SE Fuel Pressure Question
What can affect fuel pressure other than the fuel pump? I seem to be having a fuel pressure problem with the stock pump and with an aftermarket pump (tried both). I know the fuel rail has a dampener and pressure regulator on it. Is there a simple test for these? Can't seem to get my SE going again after doing the tank cleaning and sealing. I have checked the tank twice and everything seems fine.
07-19-14, 12:13 AM
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84SE-EGI helpy-helperton
My guess is your fuel filter is probably clogged up from trying to pump the detritus from the tank cleaning through it.
It's not cheap, but it's EFI pressure specific and get the right one to avoid a car fire. Aside from that, the Fuel Pressure Regulator (FPR) on the fuel rail shunts flow at high demand forcing full pump pressure against the injectors - something like 55-65psi max - when there's vacuum applied to the lead. Without that vacuum to shunt the FPR, you should be getting 47-55psi nominal at the fuel rail. Pulsation dampners are located on the end of the fuel rail and at the fuel pump - there are 2 to stem 'water hammer' effect through the fuel lines. I've never seen a bad FPR, and when they fail they leak fuel. I've also never seen a bad Pulsation Dampner, so I doubt that's the problem, either.
Describe your running (or not running) conditions a bit better and we may be able to help out with troubleshooting. Typically, after a tank cleaning all that crap floating around will get to your filter sooner or later and clog it up. No way to clean, so simply replace.
It's not cheap, but it's EFI pressure specific and get the right one to avoid a car fire. Aside from that, the Fuel Pressure Regulator (FPR) on the fuel rail shunts flow at high demand forcing full pump pressure against the injectors - something like 55-65psi max - when there's vacuum applied to the lead. Without that vacuum to shunt the FPR, you should be getting 47-55psi nominal at the fuel rail. Pulsation dampners are located on the end of the fuel rail and at the fuel pump - there are 2 to stem 'water hammer' effect through the fuel lines. I've never seen a bad FPR, and when they fail they leak fuel. I've also never seen a bad Pulsation Dampner, so I doubt that's the problem, either.
Describe your running (or not running) conditions a bit better and we may be able to help out with troubleshooting. Typically, after a tank cleaning all that crap floating around will get to your filter sooner or later and clog it up. No way to clean, so simply replace.
07-19-14, 01:05 PM
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the stock fuel pressure regulator is tied to engine vacuum, so with the engine off, i believe it should be 36-43psi, and with the engine idling, it is ~40psi - intake vacuum (we'll say -15psi) = 25psi.
if you think about it, when they do this the pressure between the fuel rail, and the manifold stays constant.
if you think about it, when they do this the pressure between the fuel rail, and the manifold stays constant.
07-19-14, 11:01 PM
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I should have read the FSM. It shows pressure at idle around 28 to 30 PSI. That is what i have. Got the bitch running...finally. Not well mind you, need a new TPS and to set everything to specs.
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