HELP! my car won't run longer than 1 hour!

well heres the story, to give a little background on my problem. about 1 year ago i had a shop put TPI on my 89 camaro rs, (orig tbi 305) the motor is currently a 350 with a few mods, nothing to drastic so i wont mention.

The problem i'm currently having is after driving for a while on a warmer day (ie 70-90 deg) the fuel pump will start to whine and the car spits, sputters, and stalls out.

Although on a 40 deg day i wont have a problem with it all http://web.camaross.com/bb/frown.gif and my mechanics keep saying its fixed, but i end up stalling out again 2 days later after i get it back.

btw it was a brand new ac delco pump.

Any input would be great!

Thanks http://web.camaross.com/bb/smile.gif

[This message has been edited by camaro_rsx (edited May 31, 2002).]

Make sure your gas tank is being vented. Try running it with the gas cap off and see if that helps.

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Isn't there a relay of some sort that you can check out?

I had a car that did the same thing, it would stall out after about a half hour if the temp was over 90*. I installed a pressure guage on the fuel line and the pressure would bounce up and down and then the car would stall. If I would put fresh gas into the tank then it would start running fine again. Talking with another guy he thought the pump was overheating and going into cavitation so I replaced the pump and it fixed the problem for about a year and then it started again. The pump had a lifetime warranty so all I was out was time. I think if you replace the pump your problems should be fixed and ont word of advice try to keep you gas tank full and don't let it get below a 1/4 of a tank full. It helps keep your pump cool and last longer.

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Wayne Best
Best Racing
67 rs Camaro
355 cu in Chevy
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87 Formula 350 w/388cu.in. motor

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If you want to get to the bottom of this buy an FI-style fuel pressure gague and install it somewhere you can see it (I duck tape mine to the windshield for a few days when diagnosing problems). Watch what your fuel pressure does. You'll know if it's a fuel pressure problem because the readings will start to get whacky when the problem crops up.

THEN start replacing parts as appropriate. Fuel pressure problems are very annoying and very few people ever actually diagnose them, preferring to throw parts at it for days, weeks, months, maybe never figuring out the problem.

dunno about the tank being properly vented, but when i took the cap off, the problem shows up faster. (ie. car was running for about an hour, no problem so far, took the cap off, pump started whining)

the mechanic already replaced the fuel relay

and its a brand new ac delco pump, so unless it was defective from the factory, (and i don't want to rip out the rearend again to get at the pump just yet)

and we've had a fuel gauge hooked up to it when it was acting up before, pressure would be at 40-45 (i think thats around normal) then when the pump would start whinning, the pressure would drop to like 5-10 psi.

http://web.camaross.com/bb/smile.gif if anyone else has any ideas i'd appreciate the help!

[This message has been edited by camaro_rsx (edited June 03, 2002).]

Does anyone else have any ideas?

Just got my car back from the mechanics, and of course, after driving for 3 hours, the pump started whining again

argh, this is getting frustrating

A few years ago, while driving from Texas to California, I went through three brand new pumps that did the same thing as yours. The third one was the charm! What a pain in the a$$, though. The last one went out 20 miles west of Needles, just after filling the tank (and buying another pump, just in case). Luckily I travel fairly well prepared for such emergencies. I was just afraid that me, the car, and half of I-10 would blow up from all the gas that spilled all over the roadway when I dropped the tank. BTW, I have since $hitcanned the Delco in favor of a Walbro.

<font face="Verdana, Arial" size="2">Originally posted by IROC&ROLL2:
A few years ago, while driving from Texas to California, I went through three brand new pumps that did the same thing as yours. The third one was the charm! What a pain in the a$$, though. The last one went out 20 miles west of Needles, just after filling the tank (and buying another pump, just in case). Luckily I travel fairly well prepared for such emergencies. I was just afraid that me, the car, and half of I-10 would blow up from all the gas that spilled all over the roadway when I dropped the tank. BTW, I have since $hitcanned the Delco in favor of a Walbro.</font>
You changed the pump on the interstate? I applaud you. That is dedication.

Anyway, did you get the problem fixed? One more thing. You did change the filter right?

if it over heats ive got the solution for you.. move up here to Minnesota.

heh, it doesn't overheat stays around 180-200 all the time.

its a heat related problem with the fuel pump

I had the exact problem a couple of years ago that ended up being a vapor lock type of thing from my fuel lines being too close to my headers. Next time it stalls out on you try relieving the pressure on your fuel system through the schrader valve. Make sure to cover the valve with a rag or something so it doesn't spray everywere or in in your eyes, and caution the fuel can actually be quite hot. Every time my car stalled out on a hot day this would fix the problem but it eventually got anoying and I just bent my fuel lines carefully as far away from my exhaust as possible without kinking them. Try this before spending the money on a new pump, I replaced mine twice before figuring it out. Good luck.

o yea i also forgot

theres a very bad fuel smell from the front of the car when this all happens, don't see anything leaking from up front

any extra input will help thanks

sorry to hear about the pump problem.it definately,sounds like it's over heating. is the pump turning off when you shut the car off?if this car isn't your baby(not in good condition)you can cut a hole behind the rear seats to gain access to the pump.if the car is nice i wouldn't do it.
hope this helps you

blown yellow:could you do me a favor, and read a post titled vapor lock and tell me if this sounds like my problem

Have you put a new filter on yet? No lie, I've seen plugged filters do this. It seems that at rest, whatever is in the filter settles, and after running for awhile, the contaminates get back into the filter media and clog it. A restriction like that will lower pressure at the rail, and cause the pump to be noisy.

I have not had problems w/ Delco pumps, but they are none the less, stock pumps. I too have a Walbro.

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