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fuel pressure reg.

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Old Dec 26, 2003 | 02:10 PM
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fuel pressure reg.

I think my fuel pressure regulator is gone but thought I'd run it by others before replacing.
The problem is when I switch on the fuel pump(manually for now) it doesn't sound like it builds any pressure. I tested the pump and it's good but it flows freely in the line. So I pulled the return line to see if it was bypassing the motor, unfortunatly nothing. Concequently the car will not start. Can anyone think of anything else it might be?
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Old Dec 26, 2003 | 02:24 PM
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rynberg's Avatar
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Does the car start with the gas pedal pushed all the way down?
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Old Dec 26, 2003 | 02:35 PM
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Originally posted by rynberg
Does the car start with the gas pedal pushed all the way down?
Without any further explanation this sounds as though it would get exciting in a hurry if it did start. However there is a program in the ECU to unflood a motor it will shut off the fuel if you attempt to start with it floored.
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Old Dec 26, 2003 | 02:37 PM
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I tried flooring it with no luck. Is there any other info that might help explain the problem?
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Old Dec 26, 2003 | 02:39 PM
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rynberg's Avatar
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Originally posted by TireSmokin7
Without any further explanation this sounds as though it would get exciting in a hurry if it did start. However there is a program in the ECU to unflood a motor it will shut off the fuel if you attempt to start with it floored.
Haha, yes, you do have to let off quickly once the car starts....

If the car does start with the throttle fully opened, it is likely that the FPR is bad.

xteg: My FPR failed earlier this year, PM me with any other questions or post back here.
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Old Dec 26, 2003 | 02:45 PM
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From: vermont
The biggest problem I may have with that is, my fuel pump is on a manual switch right now. I don't know if that will make a difference but I have only had it close to starting once or twice.
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Old Dec 26, 2003 | 06:36 PM
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any other ideas?
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Old Dec 27, 2003 | 08:15 PM
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I have a good stock fpr with fairly low miles that I will sell cheap if you want it. How's $15 shipped?
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Old Dec 27, 2003 | 09:30 PM
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Sounds like there's a little misunderstanding about how the FPRs work. Think of it this way, your fuel line is a straw and your the fuel pump. Poke some small holes in the sides of the straw, these are your injectors. Start blowing through the straw, there's very little pressure inside of it and not much coming out of those little holes so everything goes flying out the end of the straw. The end of the straw is your return line where the fuel goes back into the tank. Now slowly squeeze toward the end of the straw with your thumb and forefinger while blowing through it. The tighter you clamp down on the straw the harder it gets to blow through it, the pressure inside the straw goes up, more water, air (whatever is in your mouth) comes out of those little holes (injectors) the harder you clamp down with your fingers and of course less comes out at the return line end because you're restricting its return with your squeezing. Your fingers are acting in exactly the same way as a fuel pressure regulator. The FPR essentially plugs the line to build up pressure on the injector side. If you're not seeing anything coming back from the return line it doesn't really mean its the FPR, it's more likely the pump is bad or not getting power, a fuel filter is plugged, a line is crimped somewhere etc. It could also be the FPR but just wanted to clear up the confusion

Kevin T. Wyum
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Old Dec 27, 2003 | 10:28 PM
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I didn't read all the threads but if you have removed the return line with the pump running and no fuel was diverted back to the tank it's likely the pressure reaching the regulator is low. For example if the regulator is designed to keep pressure at 35 psi and the pump/filter/lines can only deliver 20 psi then there would not be any extra fuel/pressure to be exhausted past the regulator. The pump itself should put out about 30 % more pressure than the system is designed to use. This is there for speed of delivery/power/etc. The likely fault is the pump/filter/quality of current reaching the fuel pump.
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Old Dec 29, 2003 | 03:00 PM
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From: vermont
found out where the fuel is going. You'll love this! It's going into my oil. any great ideas for fixing that? Or how it's getting there(control rings etc.)? I did check the compression and it was good but unfortunatly I don't think that matters at this point.
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Old Dec 29, 2003 | 10:08 PM
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From: vermont
?
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Old Dec 29, 2003 | 10:16 PM
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Injector stuck open?
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Old Dec 29, 2003 | 11:15 PM
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From: vermont
would that cause fuel to end up in the oil?
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Old Dec 30, 2003 | 11:40 AM
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From: vermont
I am just worried that it may be rebuild time, but if it is just one injector stuck open, does anyone have one they would sell cheap? Or any other ideas for what it could be?
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Old Dec 30, 2003 | 06:27 PM
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???
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