HEI no start

[B-Ball]

I have a 96 GT with hei mod and external coil. I used the 95 wiring diagram to run this. First attempt, car would run then sputter and die unless the throttle was held down a bit. At higher rpm's it would choke and die. (Tach read normal) I could get the car to drive at this point. Seemed as though the timing was off.

I then switched to a copper bracket to improve the ground. It was running great until the hei got too warm and it sputtered and slowly died. (tach jumped around and would not read properly).

I regrounded the bracket to the main transmission ground and now the car wont start. It will roll over, fire once, and die. (Tach bounces around and does not read properly.

I have read through every forum and post regarding this topic. I have found that poor grounds, bad hei's and incorrect wiring are the faults. I have triple checked wiring and that follows schematic. Ground should be solid. Maybe I fried the hei.

Has anyone been successful with running this setup on a 96 gt?

Please advise, thank you.

[ncornilsen]

I run an HEI setup on my probe. I had trouble at first, but it turns out the timing was off.

did you disassemble the distributor to extract the OE coil? If so, make sure the plate thing that signals the hall effect sensor is oriented correctly.

Is the OE coil and ignitor completely disconnected? If the OE Ignitor failed as a dead short, it could be interfereing with the HEI module.

I would also check the timing. when I did my upgrade, I didn't move the distributor but there's enough slop in the tin plate thing I mentioned to adjust the timing far enough off that the car wouldn't run. Fixed the timing and I was good to go.

[ChillinZX]

Put a heatsink on the HEI like computer enthusiasts do. Better yet, get a cpu liquid cooler on it, lol.

[ncornilsen]

Mounting the HEI to something that contacts the entire metal backing of the HEI is important to making it survive. But, if it's still getting really hot, something else is wrong. (IE, the old igniter is still connected, or the coil is bad.)

I have mine mounted to a 1"x4"x1/4" piece of aluminum, and it handles the heat no problem.