[Brad Waller]

Here's a fun one. One day driving to work (yes, I daily drive my Chevelle) the engine just shut off. I coasted to a parking spot and it re-started immediately. A dozen yards later it did the same thing. Ended up doing that maybe six or so times that day, with no pattern (bumps, steering angle, etc.). That weekend I jiggled every wire and played with the ignition switch, HEI, shifter, fuse box, etc. I used my rubber mallet and tapped all around. I let it get hot. Nothing.

So I figured I would drive and observe. Test drive around the neighborhood and everything was normal. I drove to work the next day and it was fine. I drove home and got into the garage and turned off the ignition. The car kept running. The only way I could shut it off was to pull the power wire from the coil.

Does this point to the ignition switch?

 

[Coppertop]

Brad,

Aftermarket ignition?

Aftermarket wiring?

Work recently done to the car?

For many, a suddenly dead car can be traced back to loose/poor connections at the firewall bulkhead connectors. Especially so if the whole car goes dead. Do you lose ALL power, or just ignition power?

The fact you said you couldn't turn the car off though...that would not indicate a bulkhead that was loose/dirty. It could be the switch, but need more information on the other questions.

 

[Brad Waller]

Original wiring (other than what's been worked on and added to over the years), original (I think) ignition switch, and nothing new done to the electrical system. The only thing not stock in the ignition system is I did an HEI conversion about 30 years ago.

 

[Jim Streib]

For right now since you had to pull the power wire from the coil to get it to stop running, disconnect the battery while it sits unused.

Jim

 

[Coppertop]

For right now since you had to pull the power wire from the coil to get it to stop running, disconnect the battery while it sits unused.

Jim

That's an excellent point Jim. If there is something wonky going on with the circuitry in the ignition switch, some item(s) could be remaining "hot" and drain the battery, or worse, actually get hot from current being pulled thru a bad connection.

 

[drivejunk]

If you put the HEI on a relay, the relay might be sticking. I listened to a stereo person and used a relay at first, and before long sometimes I'd have to thump the relay to shut it off. Or pull a wire. The fact is that no relay is needed, never was. Just an added potential failure point and complexity for complexity's sake.

The dying was not part of my experience but had it been, that would not have been a surprise. Your ignition switch would have to be severely scrambled, probably to a point of not being able to turn the key, to make the engine run on. So I'd be glad to bet a beer that a relay is in place. And has gone bad.

 

[Jim Streib]

I looked at your video and it looks like it has aftermarket gauges under the dash, some type of rocker switch zip tied to the column, some white colored wire inside the driver's fender, and other things and while the clarity of the video was not the best, it didn't look bad like some cars I've seen through the years.

Yep, I think you are going to need some tools to help figure things out or you can certainly be a parts swapper and replace this, that, and who knows what and hopefully cure the issue(s) and then after all of that might find out that a brand new part you put in was defective right out of the box.

If you go and start it again and it still doesn't shut off with the key, then this is good from a troubleshooting aspect and then I would be getting out a volt meter to see if the HEI power wire is still powered up with the key off and then if so, maybe see where it is wired in at and then eventually get back to the ignition switch or further.

I wonder too, if maybe something got added into the fuse block your foot might have bent over some connection to where it is now making connection to something it should not be touching ?. Maybe too look at the backside of the triple gauge pack and see if anything is bent over and making connections to something it should not be touching ?.

Jim

 

[Brad Waller]

All great ideas. I'll check for power when off for sure as I don't want to kill the battery or cause a fire! I would love to put in all new wiring, but that's a task for another time. I've got some great things to check over the weekend, and might add a few telltale lights to see what has power.

 

[Malibu70]

[edit] Sorry I later realized your 1967 has a different location for the key than my 1970.

 

[71350SS]

the engine just shut off. I coasted to a parking spot and it re-started immediately. A dozen yards later it did the same thing. Ended up doing that maybe six or so times that day

This is not about anything else except the frequent stalling and not about anything else.
If it continues to do this before restarting it go out and remove the vacuum advance's vacuum hose and plug it with a screw or a golfing tee. (excellent for plugging vacuum hoses)
The symptoms that you're describing is something that was common to the late 70's and the 80's HEI ignitions. The small wires going to the pickup coil would get worn out by the vac advance can pulling on the plate and that actuates the ignition advance (separate from the mechanical advance) and when this happens the wires would ground out on the inside of the HEI distributor.
By removing the vacuum hose and stopping the vac can from pulling on the plate the ignition won't cut out. I'm not positive that this is your problem but it matches up with what was a common problem back in the 80's .

IF there's no vacuum to your distributor and you don't use the vac advance at all then dis-regard this.

 

[Malibu70]

The second paragraph in the first post mentioned an incident of the engine not shutting off, which in my book is not a distributor problem but of an uninterrupted power supply to the distributor, or a case of dieseling / run-on. The HEI is not a magneto so it will spark with inputs of power and rotation.

 

[Brad Waller]

Follow up, but no cure. I checked the voltages and saw nothing odd, but of course, the car is working perfectly with no more engine shut off or continual run-on. I spliced in a wire so I could more easily disconnect (if needed) and monitor the power to the coil and I'm driving around with a multimeter on my passenger seat.

The HEI is actually an interesting possibility. The distributor was last rebuilt in 1997, about 60K miles ago. I'll see if I can see any wear or indication of anything around the vacuum can.

 

[Brad Waller]

Yesterday after working flawlessly the shut off happened again. This time the car would not run. I was at a stop sign when it happened (the first time) and it cranked and started by shut down as soon as I released the key. Honestly, that was good news as it's one more clue and might allow diagnostics.

After a minute or so of waving people past me and moving every switch, knob, and the shifter, it restarted and ran again.

The next time it happened was in a parking lot, so I was able to go under the hood and check voltage to the coil. I don't know if this is how it is supposed to work, but the coil had power when the ignition switch was set to accessory, but not when it was in the on position. It really seems to be pointing to the ignition switch, as I saw some flashes of power as I turned the key slightly near the normal "on" position.

The quick solution was turn the key to crank the engine and then quickly turn the key to accessory and the engine kept running.

This weekend I will do some checking of the power coming out of the switch as I turn it, but I have a spare switch and will likely swap it out. Assuming my hands are small enough to do the job without dropping the dash. If I have to drop the dash, I might end up replacing the headlight and wiper switches, adding a USB charging port to the cigarette lighter port, replacing the dash pad, vents ...

 

[oldcutlass]

You could have just run a jumper 12/14ga wire from the battery to the HEI Batt terminal. It does sound like you are losing power at the distributor, where is it getting power?

 

[Brad Waller]

Since this is an HEI swap, the ballast resistor was bypassed and power should be coming from the replacement wire. I have not actually traced that wire to see where I wired it up to 30+ years ago...

 

[RICH1965]

I would probably replace the ignition switch just to eliminate it as a possible or contributing cause.

 

[Brad Waller]

I got a new ignition switch, but this will be more of a project since my dash pad is cracked and this makes a good time to replace it. And I may as well do all the other switches while they are easily accessed.

 

[Brad Waller]

Might be the final update. The ignition switch pretty much stopped working and I really wanted to drive the car. It is my daily driver and there will be a car show at the local high school in a few weeks that I've been asked to judge at, so I didn't want to take it apart and have it out of service for a while.

I figured I would try to get the plug off the switch and just use the new one, but that was impossible. I was able to get my hand there, but could not do anything else. I bit the bullet and pulled the lock cylinder out, spun the bezel off, and pulled the switch out and down as far as it would go. I was hoping to be able to get to it more easily, but there are only a few inches of wiring. I was finally able to get the plug off once I realized that I needed to leverage the outside of the clip, not the inside to get it to release. This process took well over an hour.

I swapped ignition switches and figured I would see if I could get it back into the hole in the dash.

I guess my arm is skinny enough and my fingers long enough, as I was able to see the switch. I used a finger on my other hand to stick into the lock cylinder opening to help me thread the switch through the dash. Once it was through, I put the lock cylinder in, got the bezel threaded, and was done. I'm sure the installation was less than 30 minutes.

Just for grins I took the old switch apart and it was not in great shape and I'm sure the cause of the failure.

Since then, the car has worked flawlessly.