I was driving home from work today and a few blocks from my house I stopped at a store to pick something up. When I came back to my car it started fine but shut off when I had backed halfway out of the parking spot. I tried it again and again and it wouldn't start. Finally I got it going after 45min. While it wouldn't start I was trying to hear the fuel pump priming but I don't think it came on. The relay DID switch on. So it seems like a fuel pump problem.

This also happened last summer. I let the car sit for a month because I was afraid to drive it but I didn't fix anything and it's been fine ever since. The fuel pump is now 6 years old. Both times this happened it was after about an hour of driving in somewhat hot weather with the car getting quite hot,

Anyone else experience similar problems? It's really hard to diagnose a problem when it only shows up every once in a while. Do you think it's the fuel pump? Maybe something else?

 

Besides the fuel pump, there are other itmes
Fuel sock, fuel filter etc.
Hope you did those items, too same time.
IF NOT you could be revisiting back there.
ONLY way to tell condition is by a fuel pressure gauge on that schrader valve on fuel rail.

 

If the sock is the rectangular filter thingy by the pump inlet, then yes, that was replaced with the pump. The filter was replaced more recently. I haven't checked the pressure in a while, but I do have the gauge. I just have to get the car to the gauge or vice versa. The brand of the pump is Carter which is a division of Federal Mogul.

Are there any other possible issues, e.g. an oil pressure switch for the pump?

On a side note, if I left it long enough it would fire for a second or two because I still haven't installed my "new" injectors, as the old ones are leaking.

 

Sounds like you were through.
Time to pressure gauge check it.

 

On top of it all, once I finally got it started, one of the rocker arms is clacking like crazy. I guess it didn't like all the cranking. It's been clacking for a while, and hopefully it just needs to be tightened.

 

With the same _exact_symptoms, I took my '89 2.8 v6 'bird to the shop for fuel pressure measurement; they found that the pump was failing to prime, and that the fuel p.s.i. was a little more than _half_ of what it ought to have been.

My point is that by the time you experience the hard-starting / sputtering, the fuel pump could be _way_ gone.

Of course you'll want to investigate simpler solutions--fuel filter, lines; I'd also recommend giving injector cleaner a shot.

But if you need to replace the pump, the shop may well need to drop the rear end to get at it, meaning _serious_ labor charges. My estimate from a Pontiac dealer--certainly not your best choice, but, as a ballpark: $750.

Good luck.

 

if you have the tools its not that bad at all, i didi my fuel pump in my driveway in 3 hours. bent new lines and ran them up to the front and installed a new fuel filter as well. Unfortunately, that wasn't the problem with my car, lol

 

I already did the fuel pump myself 6 years ago, so I know what I'm in for. A weekend and $100-200 is what it takes. Unfortunatley I just replaced the exhaust and already had a bunch of the rear suspension off. But I wasn't able to get the horizontal bolt out of the upper axle brace.

I meant to grab my fuel pressure gauge when I was at my parents' house tonight (where I stash all my tools), but I forgot. I haven't decided if I'm going to replace the fuel pump right now but I already have plans to do the fuel injectors, timing chain, and some front end work.

 

Jimp, I am going to have to look at Kandied's car in your sig every time you post?

Bythe way, his car was undrivable that low with the airbag system completely let out. It looked great, but it was not usable and had to be lifted in order to drive under noraml conditions or even to turn the car mildly sharp.

 

you're gonna have to look at it until my car looks like it, then you'll look at my car all the time

Mine's not going to be that low, gonna use all of the hotchkis suspension for the car, but I like the rims and i'm probably going to buy the same ones.

 

I had that same problem; the uppermost passenger side bolt, right? The nut comes off, but the bolt won't spin- I think it's bent. (Previous owner got rear-ended, must've bent the bolt).

So what I did was this- I did the pump (BOTH times, I'm on my 3rd) outside so I wouldn't blow up the house. I had the car behind the back wheels overhanging the grass, so I could dig a hole in the grass- then I just swung the track bar brace down into the hole and out of the way of the tank.

What a pain. At least now if I have to do it again, I have the tools to cut that bolt out.

 

a lift and 6 foot jack stands is a lot easier

 

Holy crap TomP, that is the funniest thing I've heard in a long time. Yeah, that's the bolt I'm talking about. I know my bolt isn't bent because I had the same problem last time I did the pump and I got it out. Basically my dad put a combo wrench on the bolt head, set the wrench against the back of the brakes, and hung off the brace. It finally turned and then came out. But when doing my exhaust, it wouldn't come off so I just swung it out of the way as much as possible.

Retrieved my pressure gauge, so I'll check the fuel pressure tomorrow.

 

Just checked the pressure: I get 44psi during the pressurization (ignition on, car off, fuel pump running), after the relay clicks off it falls to 39-40psi (probably because of my leaky injectors which are being replaced promptly), and when the car is running I get 36psi.

Thoughts?

 

Thats a normal dropoff. When the pump first primes it will gauge around 43psi and then stabliise at 38psi when the pump stops the 3 second prime.

It should hold there though at that point with the ignition left on but motor not running.

Once the car is running at idle it should remain at about 38 until you hit the throttle and it should imediately jump up to 43psi and hold as the throttle is held.

 

Okay... so how do my results compare to the norm then?

 

You may have a slight vacuum leak if you are at 36 @ idle. Check the pressure when the motor is revved and see what you are reading. Again it should be about 43psi when revved and about 38psi at idle.

 

It's certainly possible that I have a vacuum leak... especially since the mysterious orb of power is rolling around in my bumper. I tried to check the vacuum lines a while ago, but the hard lines that run near the fuel rail are hard to get at without the plenum being removed so I'll check those when I replace the injectors. I will also check the fuel pressure when revving as soon as I get a chance.

Thanks for the help Dean.

 

You welcome.

36psi @ idle is not bad by any means for fuel delivery, it is so minor it will not show. I only say to check the vacuum for leaks because it technically should read 38 if all is well. Its a sign that maybe you have a bad EGR diaphram or such and you mayt not be getting proper vaccum pressure at idle for your brake booster.

 

I have suspected for quite a while that my EGR valve is bad, but there isn't really a definitive test to see if the valve is weak. I'm just going to replace it. I think it is the spring in the valve that is dead and not the diaphragm itself.

 

i just registered to try to find more info about almost the same problem.
have you been watching your oil pressure right before the engine shuts off? if your oil pressure drops to low, the oil pressure switch cuts off power to your fuel pump which is what was happening to me. i thought it was the fuel pump but it wasn't. i ended up bypassing that oilpressure switch (put in a toggle switch to the fuel pump powered by the battery) and it didn't stall out anymore. But after months of driving like that i think i fried my fuel pump b/c that is now officially dead, so i wouldn't advise doing the same.
but watch your oil pressure b/c with me it always happend when the oil warmed up

 

That's very, very interesting. Unfortunately I don't have an oil pressure gauge, just the dummy indicators. I don't think that the dummy gauge light is out though, but I'll check on that too. Would that store a code... hmmm? Both times this happened, the engine was very warm.

 

my codes were 32 34 and 54 and i never thought about the oil pressure (mind you i didn't know a thing about cars till i bought my camaro and taught myself) but if your guages are dummy guages, you can buy a $10 guage at a parts store to test it.
i posted with my experience if you wanna see the short version of all i "fixed" when i had the prob. if i get any answers, i'll let you know and maybe it'll help you

 

Yeah, I was just thinking I should pick up an oil pressure gauge that I can tack on for diagnostic purposes.

 

IF your concern is that "spot"
it's much easier to just change the oil & install fresh stuff & while there investigate the condition of the wiring.
Oil pressure "doesn't drop" unless a few things tend to happen.
Engine speed gets to low
Pump screen fell off oil pump
Oil level is too low and ya slosh fluid back & forth (stop/go) and it causes the oil switch to activate.
It's easier to investigate before jumping to far forward with "wrong solution".
Did you also know there is a Power Steering Sensor that also controls engine shut down?
Look at the PS rubber hoses to see it, it's at steering box area.
Kinda doubt your bypass caused the Fuel Pump to die.
It was probably it's time.
20 year old cars have lots of things going wrong.
And Bubba the Mechainc isn't the best choice for repairs, is he!

 

I'm not buying the oil pressure gauge reading low thing and I'll explain why.

I have run my car without that gauge hooked up- it runs fine.

I am actually now running an Autometer sender which turns out to have reverse polarity than the AC Delco factory unit. (which I have had three leak on me in two years time). I tried buying the Autometer sender to get one more reliable. It reads backwards. I know I have very good oil pressure beforse I installed this sender so what I have done is just memorise where this gauge is now reading at idle and at running even though it reads at the top of the red zone and drops lower when revved. If the gauge reading mattered, my car would have the problem you decribed and it doesn't. This car runs perfect and flawless with on 40,000 on a new crate motor and all brand new sensors in the engine bay in the last two years except for the MAF(MAF is original, yet working fine)

 

ked85,
can the distributor play a factor in losing oil pressure at idle once warmed up? i was once told the rod that goes down into the oil pump may slip when the oil is hot and thinned out.

 

I'll give ya the best shot I can to help ya
Look at a stop sign...
That 6 sided shape is the shape of the rod from distb to oil pump.
IN OUR V6 case, I can not see it "being a factor".WHAT I THINK YA GETTING AT, or confused with it
FORD
have trouble witht the rod from distb to oil pumps (they twist frequently)
GM's (or Chevy's at least) the FACTORY V8 oil pump rod drive has a PLASTIC SLEEVE (or used to, I'm going on atleast my 1974 Chev V8 example) that hold drive part from distb to oil pump. And those plastic sleeve things break.
Again our V6 set up is a solid rod, stop sign shaped. I've pulled out several in my time & NONE were twisted damaged, etc.
COULD IT BE THE OIL PRESSURE SENDER SWITCH WHICH COULD BE VERY AGED & HAD BUBBA WORK ON IT... well only YOURSELF truly knows cause you're there & we ain't.
I think it's a "theory" UNTIL ya believe/examine, no this isn't the cause of my shut downs....
These rods slipping.....
not in a million examples you'd fine...
These rods sink rather deep into the oil pump & into the distb shaft bottom....
AND IF THE SHAFT "were NOT seated" properly... guess what part would not seat correctly!?!?!?

 

i think i might have forgotten to mention that i change/replaced the switch TWICE since i bought the car (in 2002 with 87k miles on it) and both new switches didn't make a difference....after the car would warm up (about 20 minutes) when i would come to a stop or idle, the oil pressure would drop down to 1/4 on the guage and shut off...then wouldn't restart till the engine has cooled for about 15 minutes. I've been the only one working on this car...i didn't know anything about cars other than fuses until i bought this car, spent almost $1000 having people try to figure out the problem (and not succeeding) until i decided to learn to do it myself...with the help of autozone's code printouts and reading the haynes manual several times over 7 months, i finally put the toggleswitch in bypassing the oil pressure switch. now that i am moving her 1200 miles, i want to fix the inital problem and when i saw camaro_junkies post of what sounded familiar, i thought i'd put in my experience up until now. you can find my question post on the message board if you want more info about my experience.

 

Have you ever removed the OIL FILTER HOUSING FROM THE ENGINE TO CLEAN & REPLACE IT WITH NEW PARTS?

 

Okay, well, as far as the second fuel pressure test goes:
-44psi when pump is priming
-40psi after prime, ignition still on, car off
-37psi with engine running
-43psi spike when the throttle is increased, but it does not hold at 43psi if the throttle is held as Dean said it should, instead it just returns to about 37psi (pressure regulator problem?)

As far as the problem goes, if it's not the pump, likely it has something to do with the oil pressure switch not working for some reason (switch is broken, oil passage to switch is plugged) or the wiring is bad, which are all very good ideas to check into. I'd like to hook something up so I can see what the oil pressure is and if the oil pressure switch is open when the problem occurs. It could also be the PS switch, but that signal goes through the ECM so it would be hard to diagnose.

But you guys have had a lot of good ideas, so thanks.