Intermittent stalling - won't restart (video inside)
 

I've been driving the Cobra every day for the last year and it hasn't missed a beat. This past week, I didn't drive it at all. On it's first start after the little break, the battery sounded a bit weak. I got 3 starts out of it and then the battery seemed dead. I clutch started it and got it home to the battery charger and it was fine throughout the following day. Today, the car runs for anywhere from 3 seconds to a couple of minutes but then cuts out. It's not a gradual feeling as though the carb is running low on fuel before finally stopping.

This stops instantly like someone had killed the ignition.

It takes some cranking to try to get it to refire after it stalls. The difference being, if I turn off the key to stop it, it will restart instantly.

Here's a video of it starting perfectly, but then only running for a short while before being unable to restart again.

[ame]https://www.youtube.com/watch?v=B3e0aYk6Em0[/ame]

I changed the battery and that didn't fix it.
I have fuel pressure at the carb.
I have fuel in the carb. (It's an Edelbrock carb)
It's not flooding at idle.
When it's running, it's running perfectly.

I heard that ignition switches can fail. I've tried running the car today with the headlights on to see if the dash lights do anything funny when it stalls. Everything seems normal.

Engine vacuum doesn't fluctuate in the split second it takes to stall.
Voltage at the gauge is around 12V and then 14V when the alternator kicks in. It can still stall when the gauge is at 14V, though it seems to happen less when there's RPM, engine load and higher voltage. I'm not sure which of those seem to help the situation.

It's a basic old tech car with a carb and an old Accel distributor. Even if both batteries had failed, I'd have thought that the engine would still run OK at 12-14V and not stall.

I'd love to hear your ideas!

Doesn't sound fuel related to me sounds electrical. Check your grounds. Check your coil. If your coil is hotter then the center of hot pocket fresh out of the micro...could be a problem. What sort of distributor? Dual points, electronic pick up?

Cap and rotor? check and make sure the coil wire is good and not grounding out somewhere. Its just going to be a process of elimination. Electrical problems can sometimes be tricky as hell.

Have you tried pulling a plug wire right after it stalls and check for spark? I bought this little spark plug thing with a clip on the side. You just hook up the plug wire and you can clearly see the spark. A plug will work also. That will at least tell you if it is losing spark.

What kind of Accell distributor is it - old CD unit or a points type unit? Dying right after it starts could be a bad ballast resistor (if you have points). Doesn't explain why it would not restart immediately or why it sometimes runs after the key is released for a couple minutes. If a CD unit possibly the control box is failing or has a loose terminal connection. I used to run an old Accell CD box in a Corvette and it had screw type wire terminals.

A bad coil usually cuts out after it operates a while and gets really hot. Then it cools off and will work again for a little bit. A bad condensor just plain makes the car run rough.

If it's a points distributor - it's kind of rare, but in distributors with a lot of use, occassionally the points wire gets yanked around and flexed a lot during maintenance and will break near the points but still make intermittent contact.

The fact that your battery went down is also sort of puzzling on top of the engine dying. Possibly you do have a bad ground or connection somewhere.

Sorry matey...can't help you. Motors turn otherway around down under, don't they?

Seriously though...IF you have an ECM of some kind, most need approx
13.5v or will shut down. Had that happen on an 86 IROC. Chased my tail
quite awhile on that one, as I had checked the batt first thing and it read 12v. Batt had a bad cell and wouldn't accept charge.

Looks like Z was on the right track. Seems certain now that either the dist cap, coil wire or coil is the part we need to replace.

Cheers

Craig

Craig, have you tried taking your battery switch out of circuit. Mine did this and had me stumped for weeks, would stop and then crank it and it wouldn't start ended up being a dud battery switch.

I didn't bypass the kill switch when I threw in a battery from another car in the garage. I'll give that a try tomorrow thanks.

See this is why I hate wiring/electrics. Nothing is straight forward. At least with the last big mechanical issue I had, it was easy to diagnose.

(The fact that it was seeing half a piston and a pin bouncing down the road, a smashed rod hanging out of the oil pan which had been split in half by the carnage and destruction made it particularly easy to diagnose why it stopped running :) )

That does tend to make diagnoses a little easier yeah....lol.

I just stumbled across this thread. To close it off in case anyone reads this in the future from a search, it was the ignition module inside the distributor. With that replaced (and fitting an inline power spike filter for good measure), it's as good as new.