I recently got a 1991 5.7 z28. It was half way carb swapped when I got it and I put it back to the tpi system. But now when I crank the car over the tach gage just claims till it’s maxed out and the car does not start. I’m lost on what to do.

 

Disconnect the tach wire from the dist (white wire) and see if the car runs.

 

Well if it's not starting, the first thing to do is check to see if the engine is getting fuel and spark. 'Sounds like something is not hooked up correctly...

* First do what Sofa suggested (we posted at the same time).

 

Zackly :

There are 2 wires in the connectors around your dist. A fat pink one (hehehehe) and a skinny white one (hehehehe). The pink carries 12V toward the dist, the white is what the ICM uses to make sparks butt also carries the signal back from the dist to the tach. If something about the tach is fornicated, it can prevent the spark from occurring. So, my advice is, since you KNOW the tach is messed up, is to ELIMINATE it, take it COMPLETELY OUT of the circuit; and verify that the ign works. Or not. If you disconnect the tach and the car runs you know the ign is OK and the tach is farkled. IOW divide it in half and see which half the fault is in. Since I'm STUUUUUUUUPID I have to do things in a logical rational orderly step-by-step sort of discipline otherwise I get all confused and start biting my tail which kinda hurts after the fact and besides that it bleeds. BAA AAAA AAAAA AAD. I advise you to take the same approach.