I just finished a bunch of mods on my car and now I can't get it to run correctly. When I am driving the car kind of cuts out and then comes back on, the tack bounces around allot. I seems to start happening when I have been driving the car for a while, ~15 min and gets progressively worse. I know its not the ignition control module, just replaced it today and it did not correct the problem. I have also disconnected my MSD digital 6 unit and ran the stock setup, still no effect. If I hold the key in the start position just before the started engages, the problem goes away.

I have changed my cam, head, intake, and swapped in a Manuel (T56) trans. I am still running on the stock 305 TBI auto chip. Also I have not hooked up the speedo yet.

Any Ideas as to what my problem might be

 

I had that prob when I installed my new Strip Annihilator ign box & MSD distributor...

The stock HEI wire i cut (dont need anymore) was touching the block (i had tape on it....stupid me) anyhow it was shorting against it & would cut out the ignition momentarily while the engine ran....

I also found a few more cut wires that were unprotected.......fixed all that up & now i have no probs.

Good Luck, electrical probs are a pain in the azz to find & fix

 

Yea it sounds like you have short somewhere to me also.Thats the worst possible thing diagnose in my opinion.PITA

 

If messing with the switch has an effect, that would be the first place I would look....just a thought.

 

Yeap, I would drive around with a volt meter hooked up to that ignition wire, and watch for fluctuations.

Ron

 

Thanks for the responses, I will be going through the wiring today. Could the transmission swap be causing this problem?

When I installed the transmission, I just connected to of the six wires that went to the old auto shifter (green and purple). I have them twisted together so I can start it without fiddling with wires. No on thinks that this might be causing the problem or that I don't have the speedo hooked up. Also, there were two sets wires that plugged into the old transmission, that I have not plugged into the T56.

Stroked-Z... did your problem get worse as you drove the car. With mine I don't have any problems untill I have been driving the car for a while. Then I get a few quick cut outs, followed by a bunch of cut outs.