# [SOLVED] 2000 Chev Express 2500 5.7L



## mickeyaaaa (Nov 27, 2011)

Wow, octaneman you seem to really know your stuff - been looking for solutions to similar problem - 

2000 Chev Express 2500 5.7L
Engine stalls at idle when warm. Seems random sometimes it runs fine, others I will have to start several times and keep the rpms up or It will stall at idle.
Seems to only happen when engine is warm or cooled a bit - not when completely cold.

I thought it might be the fuel pump again - just had it replaced 7 mos ago, so it took it to the shop that put the last one in. they tested fuel pressure and it was not to spec, so they replaced the pump again . I pick up vehicle and mechanic warns me that it still stalls, but the fuel pump WAS bad. I can only take them on their word, and they don't seem like a crooked shop. 

(I picked up the vehicle because the problem is intermittent - hoping it will get worse so it will be easier for them to troubleshoot, plus the guy worked on it on a Saturday for me which I appreciated).

So it's still stalling at idle, usually just after letting off the gas and braking.

History:
Apr 27, 2011 - no start, had to replace fuel pump.
May 25, 2011 running rough mid throttle, ran fine if I disconnected MAP Sensor wire.
-mechanic checked fuel pressure - 50psi good, found broken rotor - replaced cap & rotor, set timing to 0 degrees, cleared all codes and verified repair - ok.
November 26, 2011 - stalling at idle randomly. Took back to shop that did last fuel pump. They tested and found fuel pressure off spec & replaced pump on warranty - but problem still persists.


*If the IAC is bad (haven't checked it yet) can it damage the new fuel pump? the way the posts were written in this thread I was not clear on that - can a bad IAC actually damage the fuel pump somehow?
*


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## octaneman (May 13, 2009)

Hi mickeyaaaa


A fuel pump can break down in one of two ways, either through normal wear an tear or damage caused by debris inside the fuel tank. The answer to your question is no, the IAC cannot damage the pump. What the IAC can do is have carbon deposits from too much fuel forcing the IAC motor to work harder, that is why it is important to put in fuel injection cleaner every once in a while to clear out debris. 

The stalling problem does point to the IAC, but there is an issue that is very troubling and that is your fuel pump. Having replaced it several times within a very short period is not normal in your car's maintenance cycle. This leads to questions regarding its installation process such as; 

1) Is it being installed properly ? If the pick-up screen isn't installed properly it will suck in air causing the pump to overheat damaging it permanently. 

2) Was your tank flushed out when the new pump was installed ? Debris from inside the tank can flow to the injectors blocking the fuel spray pattern. The injector nozzle is very small, the smallest particle trapped inside can literally clog the injector. 


You did not mention any diagnostic codes in your post, but that doesn't necssarily mean that there isn't a problem. Test the IAC first if its bad replace it, and then move on to testing the rest of the fuel system. 



post back your findings.


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## mickeyaaaa (Nov 27, 2011)

*Re: 2000 Chev Express 2500 5.7L*

thanks for clarifying about the IAC

1. proper install - really can't say, wasn't there.

2. no, they did not empty the tank, just dropped it with 75 l of fuel in it - yeah he said it was a bugger. (i just happened to ask).

Well, now that it sat a few hours at home i went to see if it would start - wanted to make notes of all symptoms. now it won't start at all. at least it's not intermittent anymore and should be easier for mechanic to troubleshoot i hope.

Guess i'll get it towed back to the shop - maybe i'll take it to the dealer if the independent shop i've been using is not up to the task...

will run injector cleaner with each oil change from now on just to be safe too... thanks again.


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## mickeyaaaa (Nov 27, 2011)

*SOLVED: 2000 Chev Express 2500 5.7L STARTS THEN DIES*

TOOK TO SHOP - IT WAS THE FUEL PUMP RELAY. $158 parts & labor.....

if the first shop had done proper diagnosis, they would have checked for good power to fuel pump before replacing fuel pump.


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## octaneman (May 13, 2009)

*Re: 2000 Chev Express 2500 5.7L*

My suggestion to you is attempt to get your money back on the fuel pump. 


Good Luck !


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## mickeyaaaa (Nov 27, 2011)

*Re: 2000 Chev Express 2500 5.7L*

Yes of course. i have some simple work needed on my 2002 focus (nuts & bolts stuff, nothing complicated lol). i'm gonna propose he do a few hours work and we'll call it even...

thanks again.


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