engine shuts down 1995 6.5

[N9Phil]

This morning for the second time in a week the engine just dies. The first time was as I pulled in for fuel and then this morning as I came to a stop for a traffic light. When this happens the engine will crank but no ignition. When I turn the key on the glow plug light does not light. the first time with the key turned on I noticed that the glow plug light came on after 3 or 4 minutes and then it started and ran with no problems until this morning. After pushing the car to the side of the road this morning I left the key turned on and Just as I was about to call a tow truck the glow plug light came on and it started right up. I ran a few service calls and everything was fine. Both times were the first thing in the morning and temp outside was in the lower to mid 30's and it happened after about a mile from the house. I am leaning toward the FSD since I haven't had to replace it for probably 2 or 3 years. Any suggestions would be greatly appreciated.

Phil

[DmaxMaverick]

While the FSD is the usual suspect, when they fail, they have no affect on any other system (such as GP cycling). This sounds more like an Ign. switch and/or associated connectors or wiring. Grounds, perhaps, but they won't usually cause a running engine to stop. Less likely would be a uniquely failed temp sender (intermittent open/short/variable) or damage to its harness.

[N9Phil]

I thought about the ignition switch. I tried wiggling the key after it had stopped to see if the glow plug light would come back on and it wouldn't. After the glow plug light came on and it started up I tried wiggling the key and the car didn't shut off. It looks like something might be getting hot and after it sits for a while the glow plug light comes back on and everything is fine again. This theory seems wrong because once everything works again it goes for days before it quits again. I have had ignition switches go bad in Suburbans before but when the did the just went out and no coming back.

[DmaxMaverick]

The ign. switch is not part of the lock cylinder. It's actuated by linkage, located on the top of the column. A worn system, key to switch, will have quite a bit of play before input from point A (key) meets output by point B (switch contacts). If it hasn't been visited in a long while, it should be near the top of your list. At the very least, check the throws, and the connector (probably brittle or burned). A burned connector, in any way, indicates poor contacts (or it's just really old - same result).

[sctrailrider]

Like Dmax stated, the "switch" is down the column about half way, that would be a good starting point... get it starting point LOL...

[JohnC]

+1 on the ignition switch. My '95 had a flaky switch that sometimes wouldn't power the transmission, only when it was cold...

[N9Phil]

Ignition switch make a lot of sense. Have on ordered will have in two days (Amazon Prime)
Will follow up as to the results in a few weeks if this solves the problem. Thanks.

[N9Phil]

Found the problem. I started the car and left it run for 15 minutes before taking off this morning. I wiggled the cables under the dash for the start switch and everything was fine. As I started to go it quit but it started right up again. I went about 2 miles and it quit again. I glide about 2 city blocks before I could get on a side road. I decided to check under the hood and see if anything was loose. I found the extension cord for the remote FSD wasn't pushed all the way in so I pushed it in until it clicked in. The glow plug light now worked but now it would crank and still not start so I decided to replace the FSD with my glove box spare. When I undid the plug that I had just plugged in I found that one pin was bent over and not making contact. I straightened the pin and plugged the connector in and low and behold everything works. It looks like this plug was loose and after running for a while the heat of the engine caused it to open and disconnect the remote FSD and then after a short time it would make contact and allow the glow plug light to work and the engine to start. This connection hasn't been touched for maybe 3 or 4 years when I mounted the FSD in front of the radiator. I always like these intermittent challenges I am seeing more of these than ever before with appliances today.

[Robyn]

Glad you got it fixed easily. :):):):)

[JohnC]

And, the price was right!

[trbankii]

Always nice when it is a “simple” fix - the downside is the time it takes to find that “simple” thing!

[N9Phil]

I had mentioned that I had ordered an ignition switch on Amazon using Amazon prime. That was about an hour before I found the problem with the FSD extension cable. After I returned home I tried to cancel the order. I was informed that it was not possible and that I should either refuse the package or request a return label to return the part for full credit. In our area Amazon prime lets you drop of the return package at designated Kohl's stores for FREE return. A few hours after dropping of the package to Kohl's I received an E-Mail from Amazon stating that my credit card will be reimbursed for the full amount within the next three days. Looks like Amazon Prime is the way of the future.

[N9Phil]

Engine shutting down came back again a couple of days ago. The same thing as before. About a mile or two from the house it would just quit. I lifted the hood and played with the FSD extension cable and the glow plugs would go on and it started up after about 5 minutes. I drove the car all morning and no problems. That afternoon I stopped at a store about 8 miles West and it started fine but when I got to the road waiting to turn it quit again. I played with the connector again and nothing worked. I then spliced the Black ( the wire that seemed to be the problem in the past) wire around the plug and still no start. So I called the tow truck. The next morning I went out and tried the key and the plugs came on and it started up. I drove it out of the drive and pulled it back in so as to have it easier to work on. I used a paper clip to check for codes and there was none. An hour or so later when I went out to check to see if I could find the problem it was back to no starting again and the glow plugs would not fire up.
This morning I hunted up the manual and started to trouble shoot the problem. I found that the check engine light stayed on and I could not get the diagnostics to work. I pulled the PCM and disconnected it and the check engine light went out. The manual stated that I had a problem with my PCM or the Prom. I had another PCM that I had pulled from my parts car a while back but I had to find it. After a while I located it and put my current Prom in to the PCM and when I hooked it up everything fired up great. It looks like something in the PCM would break down and when sitting for a while it would work. Thank goodness for my parts car it has saved me many times.

[More Power]

Unless I missed your mention of it.... Have you tried a spare PMD? 1994+ 6.5 owners should have a spare anyway. Like a spare tire, you hope you never need one, but it's there if you do. And, it's a great troubleshooting aid.

[N9Phil]

Yes I have tried a spare FSD. I carry one in the glove box. I agree that this is a must to have a spare with you. When I first started with this problem the first thing I did was try another FSD. Until I dug out the shop manual (another must have as far as I am concerned) I was at a loss. Following the trouble shooting procedure was the key to finding my problem. Between this site and the shop manuals I have been able to find and repair every problem that I have had with all of my diesels.