Car shut off while idling in the driveway:

I planned on taking the car out this weekend for the first drive of the Spring. I wanted to get the engine up to temp and then shut it off for a few minutes and then test the warm restart. I just replaced the battery cable and wanted to see if it made any difference.

So I started up the car and pulled it out of the garage and while it was warming up, I had all of the lights on so I could watch and see if there were any charging issues while I cleaned out the garage. About 20 minutes later, I approached the car to get it in and pull it into the garage. The car just shut off! No sputtering, the lights were all nice and bright. It just shut off. I was suspecting a fuse but I noticed that all of the lights were nice and bright (just like if the engine was running), the electric fuel pump was still running, and both of the A/F gauges were still active, the dash lights were still on.
I grabbed my meter and quickly checked the battery voltage (with everything still on) it showed 12.53v at the battery. So then I turned the key off. After about 5-7 minutes of thinking about it, I leaned in and turned the key
(just to see what would happen) and the engine fired right back up just as quick as it shut off. The good news is, the new battery cable worked out great on a hot restart! So then I immed iatlely pulled the car back in the garage and shut it off.

It appears that the battery, alternator, fuel are all in good working order. I am assuming the since the car was idling, the ignition must have lost voltage. But it re-started like a champ and the ignition box had a solid red light.

I plan on chasing the wiring from the MSD Streetfire box back to the battery. Then follow the RUN wiring from the box back to the steering column.

What else would you suggest to look at? (Ignition switch shorting out?)

Thanks!
Dave

look the bulkhead connections over good for any signs of corrosion or damage, also check the ignition switch connection at the base of the steering column for the same.
you mentioned the ignition box indicator glowing. check the blue and brown [crank and run] power to the box wires to their bulkhead connections, as well as from the bulkhead to the ignition switch.
i'm just guessing the MSD street fire box is wired similar to a 6AL in that the ballast resistor is bypassed ?

You are correct about the Streetfire box. It does not require a ballast resistor.

My Streetfire 12v RUN wire bypasses the bulkhead and goes directly to the wiring 12v RUN wire off of the steering column. I did this to make sure there was no issues getting the 12v required for the box. I spliced into this wire about 2” after the steering column connector. *I will check out this ignition switch connector at the steering column.

The ignition box indicator was glowing solid red when the car was idling. After it died, the indicator light was off. This is why I am guessing that the ignition switch or the 12v RUN wire that leads directly to the ignition switch connector at the steering column may be the issue.

The above is why I am guessing that my ignition switch may be starting to fail. I have had this car for 19 years and I have never replaced this switch. I have no clue if it is original to the car, but I do know that the connector at the steering column is the OE style connector.

Thanks for the response!
Dave

Until it does this more than once I wouldn't worry about it......

take out the idle mixture screws & shoot a good blast of brake kleen into both of the ports. before removing them 1st count the # of turns into lightly seated so you can quickly return them to their exact positions when done

Thanks for the replies.

I need to find out why this happened. I dont want to be stranded out with the kids.

The carb was taken apart over the Winter and all air/fuel holes were blown out with carb cleaner and I put new gaskets where needed. I dont think it is a carb problem since it shut off like a light switch.

I chased the 12v battery wire tonight and tightened a few connectors, but I did not find anything obvious. I then checked the distributor connections and found one a little looser than I liked. So I got that connector tightened up and then heat shrunk the dist connector to make sure that it does not vibrate loose.

Saturday I will chase the 12v RUN wire back to the column. I picked up a new ignition switch today and will start that swap this weekend. I am now wondering if my hot engine-slow crank issue and this shutting down at idle issue are both related to the ignition switch.

Thanks again!!
Dave

I would check the 12v switched signal to the ign box. BUT, i have an MSD streetfire on my truck, the light doesn't turn on with the 12v switch. it signals from the reluctor/pickup coil in the distributor.
just dbl checked, turned my ign on, motor not running, the light wasn't on. turned it over without pumping the gas so it wouldn't start (bowls are a little empty) and i could see the light flashing. engine running the light is just solid.

This may very well be a ignition or current contact issue, I would start it and let it idle and watch it for at least 20 to 30 minutes to see if it will do it again
If it does stop have your electrical test tools handy and start looking at the ignition feeds and voltages, it, the ignition feed to the box or coil, may be heating up and going open (AKA as a high resistance open or high joint), no electron flow
Good luck, let us know what you find, BTW how good are all of your grounds?

""I would check the 12v switched signal to the ign box. BUT, i have an MSD streetfire on my truck, the light doesn't turn on with the 12v switch. it signals from the reluctor/pickup coil in the distributor.
just dbl checked, turned my ign on, motor not running, the light wasn't on. turned it over without pumping the gas so it wouldn't start (bowls are a little empty) and i could see the light flashing. engine running the light is just solid.""

I just double checked mine too and it is the same as yours. Key to RUN and no light at the box. Crank and it shows flashing light.
I mentioned previously that I found a couple of loose connections under the hood but I did not say which connections. One was the large RED wire at the battery. The connector came apart a little easier than I would like but I think it was good, but I tightened it up. The second loose connector was the distributor connector. It slid apart easily, so I tightened it up and then taped it together and now it is tied together. This may have been the issue.

I just checked the voltage for the RUN at the steering column connection (my new connection that bypasses the connector and goes to the MSD box) and it was tight, heat shrunk, and showed 12v with the key in the RUN position. I stripped off the heat shrink and I am letting it stay uncovered so that I can use it as a 12v RUN check if this happens again.
Thank You!!

Cab:
When the car shut off at idle, I did not have any good places to check the RUN voltage at that time because they are all heat shrunk. As just mentioned, I uncovered the one under the dash and I will use it it this happens again for a check point before shutting off the key.

I am going to do another test at idle and I will check back in.

Thanks again!!
Dave

I just finished up testing the idle in the garage (78 degrees in garage) for 30 minutes.

Hood open (to watch MSD box), 6psi fuel, 16 degrees initial timing, and headlights off. After 25 minutes and several voltage checks at the steering column/MSD 12v RUN connector, I got a steady 14.2v and no issues and I had 14.3v at the battery.

For the next 5 minutes, I turned on the headlights and the same voltage check was 14.1v at idle and 14.3v at the battery.
Then I shut it off at 30 minutes and let it heat soak (hood open) for 6 minutes. Battery voltage was at 12.65v and I wanted to check the hot restart. I turned the key and it slowly cranked for about 1-2 seconds and then it started and idled.

So except for the slow crank (which I has hoping the new battery cable would have solved), the car idled well for 30 minutes.

Thanks everyone!!
Dave

With the slow crank you might want to install another ground from the engine to the chassis and see if that helps. As for the engine dying that could be a coil winding opening up when it gets hot. If you have another known good one I would swap it out

Gus

Also check resistance of the dist. pickup coil. Had one years ago that would lose continuity after running for a while. When cooled off, would make contact again to run. Next time it died I check leads & found "open circuit".
The coil has a range of ohms that are acceptable: check your ohms (maybe hot & cold).
Could give you another avenue to pursue

""With the slow crank you might want to install another ground from the engine to the chassis and see if that helps.""

Thanks for the replies guys!!

I currently have the typical battery ground going to the drivers side head (aluminum). This same battery cable is also going to the radiator support. I also have a ground on the alternator and one on the starter.

Would this extra ground go from the head down to the k-member, or to the engine mount (block side)?

What size wire would this need to be?

Thanks again,
Dave

It sounds to me that you have enough grounds if the wire gauge are big enough, what gauge are the other additional grounds?

Cab,
All of the battery grounds are of stock size. The starter and the alternator grounds are 10ga.

After doing some reading, I found a 3/8-16 tapped hole on the drivers side block just above the oil pan. I took an old 1ga negative battery cable and bolted one end to this tapped hole on the block and the other end down on the sway bar mounting bracket.

If this does not help, I may be looking at trading in the 5 year old battery for an upgrade. The coil is a 2 year old MSD Vibration coil.

Thanks again!
Dave