91 C1500 5.7 idle miss
 

Truck does not sound the same and miss began yesterday. Plugs 2 yr old. New coil (Accel) tps, ignition control module, idle air control in the last couple months as preventative maintenance. Replaced o2 today. Truck idles bad. Egr 5 years old. When I disconnected the timing wire to check timing, truck almost died so I could not complete. Any suspects?
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Re: 91 C1500 5.7 idle miss
 

My first though is to look for vacuum leaks at the base of the throttle body, well heck anywhere on the top of the engine. What about your plug wires and cap/rotor?

Cap and rotor a couple months. I sprayed carb cleaner around the throttle body and didn’t notice increase. There is some oil on passenger valley which I thought may be coming through bolts. Should I retorting them?
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Re: 91 C1500 5.7 idle miss
 

If it was running good and you replaced anything and then it started acting up I would suspect those parts. Not uncommon for new parts to be bad.

Didn’t change anything prior to miss. Changed out egr and seems to be working better. Haven’t tried disconnecting timing wire to check timing. Thanks
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Re: 91 C1500 5.7 idle miss
 

Sounds like you did replace some parts or you wrote this wrong?

I went through a 2 month trouble shooting a miss and it turned out to be a new /3-4 month old set of plug wires I put on as part of a complete tune up.

I had two new distributor caps fail during this time, trying to find the original problem too.

NEVER assume new parts are good parts.Quality of new parts are not what they used to be.

That must have been old post from somewhere. This started 7/20. Haven’t been on here in a while Thank God.
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Re: 91 C1500 5.7 idle miss
 

Not trying to be an ass or anything like that that is a quote from you first post in this thread on 7/20.

If it is not the case then you ignore it, but you did say you had installed parts in the last couple of months.