Ok i recently bought a 94 z28, over the last week it has done it several times. I am just driving along and all the sudden the tach drops to zero and it dies, then as quick as it dies it will start right back up for a second then die again. Doesn't seem to matter how you are driving at the time. Only mods are as follows, 52mm tb, underdrive pulleys, 4.10 gears and a program from pcmforless.com, also it did this twice before the program was installed.

Any help would be appreciated
Thanks
Chris

 

Update, I just went outside and started the car to go to the store. It would not start turned off the key then back on it started right up, and as I drove down the road it stumble a few times for about the first mile or so then ran great the rest of the way.

Any ideas?
Chris

 

Ignition switch maybe?

 

migth be the wires running from the colum to were ever. it happen to my car and a whole wire harness got burned up. i was having the same problem of the car would start some times and not others

 

Would your car still crank? But just not start or not crank at all?

 

Anybody else have any ideas, I checked ignition switch all looks to be good.

 

check your fuel pressure? change the filter lately? Can you hear the pump priming when you turn the key over?

 

did you really check the ignition switch? You unbolted your steering column, dropped the steering wheel, and unbolted the ignition switch from the steering column? I hope your not getting the ignition switch confused with some little 5 minute thing you can check.

 

Yes I do know what the switch is. I actually went ahead and put a new one after reading some other posts, cost me 16 dollars from gm. car done fine for about 2 hours then same problem again. Could it be opti, ignition module, coil?

 

correct me if I'm wrong but a fuel problem wouldn't make the tach drop to zero instantly when driving down the road, it is a m6 so the motor is still turning.

 

any codes getting thrown? Check coil, wires, opti, and the fuel pump to see if it has pressure. If a fuel pump is going bad, it is hard to say if it is that forsure since they can do all kinds of things.

 

No codes, new wires and plugs but not opti.

 

coil? opti? I woud check those next, could be those two most likely.

 

I was mulling this post over in my head and thought about something. My buddy's wife had a similar problem w/ her ta. Sometimes it would die while idling, running, whenever. At the time I had a service manual and we went through the power wires trying to determine the source. We found a connnector either on top of or near the steering column under the dash that supplied power to the ignition, it was fried, looked like too much current over a long time just charred the hell out of it. He fixed it, but not sure how long term the fix was, he sold it about a year after that. just trying to give you a direction.

good luck.

 

Ok for an update again, I replaced the coil and also done the VATS bypass with the resistor and also changed the fuel enable in the programming per instructions of bryan herter. When the steering column was down for the ignition switch install I looked at the wires because i read a similar post about the wiring, mine looked perfect. Haven't changed the opti yet where is a good place to get one and how much?