No start on a 4.3

[Jerryred94silvy]

I just recently replaced the intake gaskets on my '94 c1500. Did everything that the all knowing interwebs commanded me to do, plugged everything back into everything else, changed oil and replaced the coolant. And now the darned thing won't start. The motor will spin no problem (battery is fine). I can watch the fuel injectors inject fuel as they ought (it's getting fuel). And I know for a fact it's getting air. So unless I am missing something obvious, it ain't getting spark to the places that need spark. I put the distributor back exactly the way it came out and replaced the coil. Still will not start. Should I be able to see electricity arcing from the center of the dist. cap? because I do not. Hopefully it is something ridiculously obvious and easy as the truck has been sitting for awhile now and I'm itching to cruise in the thing.


Thanks in advance for the wisdom.

 

[supermailman]

Is the ground connection on the thermostat housing in good shape? There might be another one on one of the driver's side intake manifold bolts as well.

 

[supermailman]

Pic for reference, from my 95 4.3.

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[Jerryred94silvy]

Those connections look to be fine on my truck. When I bought the truck both of those grounds were bolted to the same spot on the thermostat housing so I assumed that's where they went and where I have them now. I'll switch them around and see what happens though.

There's a lot of weirdness under the hood of this thing from whoever owned it previously.... I wouldn't be surprised if something like this was causing problems.

 

[Jerryred94silvy]

Update: I cleaned up those grounds and put them on separate bolts (like in supermailman's pic). Then I charged the battery up because it was getting weak. Then I found part of the dist. cap laying on the dist. and put it back in place. Now I notice that when I pump the gas pedal while it is cranking, as I let off the gas pedal it will try to catch and light off. It does this with or without the air cleaner assembly on. I've tried choking it manually with a rag, doesn't work. So maybe a vacuum leak somewhere? or an IAC valve? I'm stumped. It started right up before I pulled the intake. Even though it was smoking out the tailpipe.

 

[PlayingWithTBI]

Here's a link on how to set up your TB, it shows what values you should set/get from your sensors. It's old but has good info.

http://www.gmcmidwestclassics.org/Web pages/Tuning the TBI.pdf