Yet another mystery problem... 92 K1500

[shibbershabber]

So after replacing many parts and chasing down different symptoms, I thought that I finally had it done...

SO, this is what I have done so far... each time I did something, it ran a little better, or at least different.

Fuel system replaced: pump, filter, rebuilt TBI, new injectors, new injector wire harness connectors
New battery, new alternator, new negative battery cable
New distributor, new plug wires/cap/rotor, New timing chain and gears
New EGR, new TPS, New ECM
New exhaust from cat to the tail pipe

So the truck is still acting a fool, not producing the power that it should... and wont effing idle:

http://s1171.photobucket.com/user/zenbadger/media/VID_20130608_173815_zps869307ea.mp4.html

so thats how its idling, it can go on for a while and not die... just back and forth.

Im thinking the IAC could be replaced? Thoughts?

 

[1997chevydriver]

Did you replace the ICM in the distributor?

 

[shibbershabber]

The new distributor came with one.

 

[shibbershabber]

update...

I bought a new IAC and stuck it in there... and it ran just fine! no ups and downs or anything, I let it run for about 5 minutes and decided that I would put the timing light on it and see if the mark still wandered. So I first checked it with the advance on and I am about 30* I then unhooked the advance and restarted it. The timing is somewhere BTDC that I can only guess at maybe 8-10* btdc???? WTF, shouldnt it be at 0*? I even took it in and had it set by a shop.
Anyhow, I plugged the advance back in and started the truck because I wanted to see how it drove since it was idling normally... well FML, I started it and it instantly died. Then it cranked and cranked. Would only start when I pumped it.

Didnt get to mess with it further as my fiance came out barking at me about revving engines at 10pm or something


Any thoughts? Ill mess with it tomorrow and see what happens.

 

[Yeti_Owner]

Thoughts? Disco the test lead and set your timing correctly to 0. It's going to run like crap with it retarded that much. The shop set it wrong, or the dizzy isn't bolted down effectively and it shifted.

As an aside, the timing can and will wander with the lead connected, by design, so I wouldn't worry about that part.

 

[4player]

I had an 88 that would not idle and I had to replace the computer, fixed the problem right away.

 

[Bearcat91]

saw you put a new NEG battery cable, but not sure when in the the list of things done...you may try and unhook the battery for alittle bit to reset the comp with all the new sensors and what not you have done. free and easy to do

 

[shibbershabber]

There is a new computer in there now, it went in before I took it to the shop to have the timing checked and then it went for exhaust work.

The neg cable went on before the distributor, though the battery has not been disconnected since the new IAC went in, I will try that tonight!

 

[///RAGMC]

Acting kinda like a bad coolant sensor

 

[Yeti_Owner]

PLEASE try my diagnostic tree on here. Stop throwing parts at it, and diagnose it.

http://www.gmt400.com/forum/showthr...WITH-A-MULTIMETER&highlight=sensor+diagnostic


Also, check your grounds!