quisterio

I think my fuel pump has finally kicked the bucket...

My car has had the problem of not wanting to start in the mornings unless I prime it up around 6 or 7 times... Even when I do this it still takes a decent amount of cranking to make it fire up.

Yesterday I went driving for a while, came home, parked the car for no longer than 20 minutes.. Came back out and trying to start it was a big no no...

I let the car prime up over 10 times, I then went to the the schrader valve on the fuel rail, pressed it in with a key, and all that came out was a very little "squirt" of fuel....

The pump primes up every time you turn the key right before I crank it, so I know it's not a bad relay, especially since I just replaced it a couple days ago.

So if the car isn't building pressure at the rail, then it's gotta be my fuel pump right?

87IROC-DAN61

Hello quisterio!!

Put a fuel pressure gauge on the schrader valve and get a pressure reading, as it could be the fuel pressure regulator, or the check valve in the fuel pump!! One is a pita to fix, the other not so much.



P.S. I'm leaning towards the vision of a new fuel pump is in your future!!

Dustytrix

iTrader: (3)

Also check your fuel filter, it would cause the same problem.

quisterio

The fuel filter is less than 2 weeks old, this problem over the last couple weeks has slowly but surely gotten worse and worse, until finally it won't start for nothing....

How could the fuel pressure regulator be at fault here? I'm just curious, the only thing that could be wrong there is the diaphragm is bad right? And even if it was bad how would that prevent the car from re-starting or even being hard to start in the mornings without a lot of excess cranking?

As for the fuel pressure reading, I can assume that if the schrader valve is only putting out a little spurt of fuel when I depress the core of it AFTER priming the system up 10 times means that there's no pressure... Correct?

I'm just gonna end up having the fuel pump replaced, not much else I can do.. This is the 2nd new fuel pump over the last 4 years of me owning the car, I don't know why they aren't lasting long..

matts86cam

iTrader: (1)

just a thought, bad fuel in the tank clogging filter?

87IROC-DAN61

Hello quisterio!!

The fuel pressure regulator obviously regulates the fuel system pressure, and the fuel injection system requires a certain amount of fuel pressure to run, no pressure = no running!!

Just because you changed out the fuel filter two weeks ago doesn't mean that it hasn't sucked up some crap from inside the tank. Check it out again, it's a cheap check, and could save you some $'s!!

Hook up a fuel pressure gauge to the schrader valve on the fuel rail, and see what fuel pressure your getting before you decide to rip out your fuel pump!! It could save you some $'s also!! The reading will provide you with a better idea as to what your problem is!!

vetteoz

iTrader: (13)

If the reg is bad for whatever reason then the fuel from the pump will just return to the tank and not build presure in the rail

But why?
By pushing the valve after priming you are only checking stored pressure in the rail, not the working pressure. You don't mention any problems while driving so could reasonably assume pump is working fine once engine is started
The pump could be fine but there are other places to lose pressure .Reg for one ,the hose in the tank that connects the pump to the hardline could be broken so the fuel doesn't even leave the tank
There are tests to do once you have a gauge to determine where the pressure is bleeding off ( assuming pump working )

quisterio

If the diaphragm is bad inside the regulator will it cause the situation you mentioned above?

87IROC-DAN61

Hello quisterio!!

Yes!!

Since the stock regulator is not "economically feasible to rebuild" it's considered disposable by GM, and you therefore have to buy the whole deal!! If this problem you have, turns out to be your fuel pressure regulator, buy an adjustable one, then you can tune your fuel system pressure to give you some better performance!! You will also get the benefit of being able to adjust the pressure for any performance mods that you plan to do in the future!!



P.S. Did you check your fuel system pressure with a fuel pressure gauge yet??

vetteoz

iTrader: (13)

AC Delco (GM ) and others make the diaphragm kit (STANDARD MOTOR PRODUCTS # PR10 ) but it is like $62

The adjustable units only include the regulator hat with adjusting screw.You still have to buy a new diaphragm or reuse your old one
http://www.summitracing.com/parts/JET-61501/
http://www.summitracing.com/parts/MAA-4315/
Note fine print
Stock or aftermarket diaphragm required for installation.

quisterio

Alright, was worried my question wouldn't get answered..

Anyways...

Dan, I actually have me an AFPR on there already, i forget what brand, TPI parts? No clue... But since then my pressure has been bumped up a good deal, and yes I did use a fuel pressure gauge when bumping up my pressure. I think my WOT pressure is at 49 psi if I remember correctly..

When I bought the AFPR I had to re-use the old diaphragm, it's like one of the only original parts left on the engine since the rebuild lol...

Like Vetteoz kinda hinted at earlier, once the car is actually running there's no problems, a little bit of a loss in "oomph" since this problem has gotten worse but nothing that's keeping the car from running properly.

Looks like it's gonna be a trip to autozone in the near future... I swear that place is my home away from home.

87IROC-DAN61

Re: Car primes up, but no pressure at the rail?
Quote:
Originally Posted by 87IROC-DAN61
Hello quisterio!!

Yes!!

Since the stock regulator is not "economically feasible to rebuild" it's considered disposable by GM, and you therefore have to buy the whole deal!! If this problem you have, turns out to be your fuel pressure regulator, buy an adjustable one, then you can tune your fuel system pressure to give you some better performance!! You will also get the benefit of being able to adjust the pressure for any performance mods that you plan to do in the future!!



P.S. Did you check your fuel system pressure with a fuel pressure gauge yet??

Quote:
Originally Posted by vetteoz

AC Delco (GM ) and others make the diaphragm kit (STANDARD MOTOR PRODUCTS # PR10 ) but it is like $62


The adjustable units only include the regulator hat with adjusting screw.You still have to buy a new diaphragm or reuse your old one
http://www.summitracing.com/parts/JET-61501/
http://www.summitracing.com/parts/MAA-4315/
Note fine print
Stock or aftermarket diaphragm required for installation.

Alright, was worried my question wouldn't get answered..

Anyways...

Dan, I actually have me an AFPR on there already, i forget what brand, TPI parts? No clue... But since then my pressure has been bumped up a good deal, and yes I did use a fuel pressure gauge when bumping up my pressure. I think my WOT pressure is at 49 psi if I remember correctly..

When I bought the AFPR I had to re-use the old diaphragm, it's like one of the only original parts left on the engine since the rebuild lol...

Like Vetteoz kinda hinted at earlier, once the car is actually running there's no problems, a little bit of a loss in "oomph" since this problem has gotten worse but nothing that's keeping the car from running properly.

Looks like it's gonna be a trip to autozone in the near future... I swear that place is my home away from home.

Hello vetteoz, and quisterio!!

I believe that you do learn something new everyday, having never had to replace/fix my fuel pressure regulator, I looked in the 1987 Camaro factory service manual, page 6E3-C2-15, and it says "Important!! The pressure regulator is factory adjusted and is not serviceable. Do not attempt to remove regulator cover" My Haynes manual says "The fuel pressure regulator is factory adjusted. Do not attempt to remove the regulator cover. If the regulator is malfunctioning, it must be replaced" So..........I took this to mean, that it's not serviceable, seems like a logical jump to me!!


I stand corrected!!!

quisterio

Well,

I replaced the diaphragm in my regulator, but to no avail...

The car still won't build pressure at the rail, so that leaves the pump as the only culprit left...

I figure the check valve in the pump has gotten stuck open, which raises my curiousity as to why this may be... It makes me wonder what the condition of the inside of my gas tank is.. Maybe there's some rust in the tank making this happen, I don't know, but if there is, I hope it's not too bad..

One last question... If there does turn out to be rust in the gas tank, does that mean that I need to have my gas tank replaced? Or can I somehow fix it myself?

Drew

iTrader: (58)

So my brother in law bought this 91 5.0 Mustang... It'd be hard to start sometimes, then one day it died at a stop sign and wouldn't restart. After fighting with it for a couple minutes I figured out it wasn't holding fuel pressure. After an hour of diagnosis I figured out the pump was running, it just wasn't producing much pressure. Turned out the rubber hose between the pump and the sending unit in the tank was rotted out, the fuel was pumping out of the pump and right back into the tank.

After you eliminate other possibilities, I'd pull the tank and have a look. It could be any number of problems inside the tank.

vetteoz

iTrader: (13)

As I mentioned back in post # 7 .Only one way to find out

87IROC-DAN61

Hello quisterio!!

There are formulations out there that will "coat" the inside of your tank, supposedly preventing rust etc...however sometimes these formulations flake off, and then cause all types of problems!! If you get your tank off, and take a look inside, and find rust, and other residue, you could coat it or just replace it with a new one!! That of course, all depends on how partial you are to your factory original tank!!

Ryan Spicer

Check your battery voltage my truck would run for about 15 minutes and then no fuel everything is brand new (pump, filter, distributor, plugs, regulator, alternator, etc.) But no fuel at carb. Found out my battery had a dead cell and wouldn't allow my pump to push enough fuel to the pressure regulator after it was running on the alternator only with no battery to assist it. Try charging the battery if its low then trying it.

OrangeBird

iTrader: (1)

If the original poster hasn't got it fixed in the 9 years since he posted the thread , It's highly likely the next owner(s) have already solved it .....

Welcome to TGO , and for a bit of friendly advice , turn off "continuous scrolling" , and always check the date of the posts your responding to .