1991 chevy 2500,5.7 liter, auto,2 wd

lemtrac7 · #1 Oct 7, 2007, 11:15 AM

Hey folks this is my first posting here and I will be grateful for any advice you have.
My 1991 Chevy 2500 pickup is sick. It was running fine until, It started missing and will not take fuel when you press the accelerator. I have some background working on engines but when it comes to diagnostics I am lost.
At the suggestion of some friends and others I have replaced the distributor,rotor,cap wires, plugs,ICV,throttle position sensor,fuel filter. What it is doing is lopping at idle and misses real bad when you accelerate. It is not flooding because there is no black smoke or raw gas smell. I have looked for wires that maybe broken or shorted and found nothing. It was running great until this problem started. It was a sudden problem. Do you think it could be the fuel pump or ? I am open for suggestions. Thanks

Flying Blue Eagle · Oct 7, 2007, 06:54 PM

Lemtrac7:: Number 1 - I got a new set of spark plug wires for my 92 2500 and it done what you say yours is doing ,I raised the hood in a good (DARK ) place ,started the motor ,let my eyes adjust to the dark and I saw a christmas tree with (BLUE) lights. Of corse it meant that the new wires were bad . took back to autozone got another set (NO charge) put them on and it purred like a kitten. another thing to check is the pick up coil down inside under dist. cap also ck. cap for cracks, look inside cap IF I have helped ,rate my answer .Thanks Have a good day good luck F.B.E.

CaptainRich · Oct 8, 2007, 11:14 AM

Do NOT spray your truck with parts. That will only weaken your determination and your wallet.

Be systematic and cost effective. If it's running rough at idle, unplug first one TB injector then the other and if the problem becomes worse, it isn't fuel delivery. One injector may be sticking slightly and causing the roughness.

You've done the secondary ignition, now it's time for the primary side: Ignition control module and ignition coil.

Flying Blue Eagle · Oct 8, 2007, 08:31 PM

Lemtract7::::: Iforgot to ask you one other thing , you said that you installed a new 9DISTributor) , when you reinstalled are you sure that you got it put back in right???? even the best mech. on earth can put it back wrong .I always marked wher the old one is at ,you drop it in a nd off by one gear and you will spend forever trying to find out why the moter is running rough and missing. check this also. F.B.E. Heres wishing you luck



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