Vettedreamer74

I was all excited after I got a timing gun and got the car running smoothly. The first day I drove it for 40 minutes on back country roads and ran it fast, no problem. The next day, I drove it for 20-30 minutes in and out of town, then I drove it in town for about 10 minutes. Sat at a stop light, turned right, hit the gas a little bit, and it shut off on me. Thankfully I coasted into a parking lot. Haven't been able to start it since, and this happened Friday. Had to have it towed. I have a HEI distributor and replaced the ignition coil. Checked as much wiring as I could. The engine turns over, and I took out a few spark plugs, and they didn't look bad. What am I missing? Originally thought I flooded it. Thanks for the help.

speedreed8

Did you change the hei ignition module. And check the wiring connector to it.

Vettedreamer74

Did not check the ignition module. Wiring looks good.

Neil B

Likely the ignition module based on the symptoms. Check for fuel at the accelerator pump and voltage at the coil, but 99% chance it's the module.

Vettedreamer74

Is that based on something I could have done or just a worn out part?

Neil B

Nothing you did. They just go without warning.

Vettedreamer74

Thank you for the help!

Neil B

It's pretty easy to replace. Try to coat the new module with the special white grease to protect the module from heat.

71VetteLover

If you used the IGN terminal on your fuse block to power your HEI you may have a bad ignition switch because the ignition switch powers the HEI terminal when the key is turned ON. My engine was also mysteriously shutting off and after a LOT of testing I finally discovered my IGN terminal was going dead (because of the bad ignition switch). So if your ignition switch is of an unknown age I suggest replacing it and your problem might go away.

Neil B

Testing for 12v at the coil will check for this.

OMF

Fuel, air, spark....got to have these to run.

-Pull a plug and see if it sparks while cranking with the plug grounded to something
-Look down the carb then actuate the throttle linkage, you should see a nice squirt of fuel
from the accerator pump
-Air is not usually a problem....

One of the three is most likely missing.....

TimAT

12v test light between the TACH terminal (disconnect the TACH wire) on the cap and a ground. Crank. If the light flashes, the module and pickup coil are both good.

truckerlary

. Had the same problem with mine. Had power in the feed wire coming into the distributor but lost power to the tach wire everytime it shut down. Changed the module runs great now.

Wee

Not sure if you are running a Q-jet carb or not....If so check the fuel filter in the carb....I had pretty much the same issue and found a half teaspoon of dirt/rust.

Brian

blk79nj

This is what happened to me. If was the ignition module. Same problem you had... it just shut off all of a sudden.

7T1vette

Got fuel?? (had to ask....)

71VetteLover

Testing for voltage doesn't tell you how much amperage is getting to the HEI and an ignition switch with burned contacts will only allow a very limited amount of current to pass. It's a better bet to replace ANY ignition switch of unknown age.

Neil B

Agreed. But if he's got 12v going to the coil and not at the TACH terminal with key on, the problem is likely the module. I'd replace the module first, but that's me.

Vettedreamer74

Definitely have fuel, it's something electrical. Ignition module has been changed, and still won't fire up. Will have to try and figure out where the current is stopping. Thanks for all the comments. I'll post when/if I find the problem.

Neil B

Do you have 12v at the BATT terminal?
If so, is there 12v at the TACH terminal?