Engine Shuts off like turning the key

[DennisG01]

I've done some searching, but admittedly my search skills may not be all that good. At this point, though, it's an intermittent issue that just started so I'd like to just get a "heads up" of things to look for. Of course, this is 5 days before we leave for out big family vacation!

I bought a FSD (PMD) and heatsink kit from PMD Cable about 2 years ago. I have it mounted behind the port-side battery -- sort of between the battery and the fuse block.

On to the problem...

Drove into work yesterday morning and the truck was then sitting for about 9 hours. Started driving home after work and the engine shut off (about 3 minutes into the drive) just as quickly as if I turned the key off. Must be electrical, right (not fuel related)? I was coasting and started the engine right back up. About 45 seconds later, it did the same thing and again restarted. I continued to drive for about 25 minutes without a problem. Truck sat for 2 hours while I watched my son at football camp (9-year old). Started the truck after practice and drove 15 minutes to get home with no problems.

This morning, drove 15 minutes to work with no problems. Sat for 5 hours then went on an errand for about 5 minutes and no problems. Sat (engine off) for about 5 minutes and then drove back to work and it shut off again about 1 minute into the 5 minute drive back to work.

So... (3) shutoffs with immediate restarts. Nothing seems to be loose. Check Engine Light never came on. Could this be indicative of a failing FSD? Is there anything else that this could possibly be? I do have a spare FSD on board. I've had FSD issues before, but this is acting different than in the past - at least from my experience.

[john8662]

what PMD did you get?

Grey Stanadyne or Black?

How long did this PMD last before doing this stalling (how old is the unit?)

Codes?

PMD mounting location is critical. The new grey units are absolute garbage and do not last under heat as well as the old black units did (and they sucked). The Grey units will not last in the location you specified, may only last a month or two there, seriously.

TOO hot in the engine compartment for these things on a cooler, the coolers are not sufficient at cooling these units in locations where there isn't moving air all the time, like in front of the battery. Only gets air when the vehicle is moving a sufficient speed. Otherwise it's just hot stagnant air, worthless for a heat sync.

My advice?

Put it in the bumper between the holes (air moving from the fan crosses this area and it's out of the hot engine compartment), or pull the intake manifold and install it on the injection pump. It actually runs cooler on the pump than on a cooler mounted to the intake or in a stagnant hot area of the engine compartment.

J

[DennisG01]

The one that is hooked up right now is a grey Stanadyne. And I agree - it's in the wrong place. I had other problems going on back when I got this one (about 2 years, give or take) and the shop mounted it for me. I had meant to remount it, but obviously I haven't thought about it till now!

The extra FSD I have is a black box, but it may not be Stanadyne - it's got a picture on it of what looks an old, Johnson outboard Sea Horse in front of a picture of a world (just lat and long).

Maybe I should just go and remount it in the bumper and hope for the best? I already have the extra cable to do it.

[john8662]

If it's stalling, its toast. Once they get to the point to where it's stalled, even once, the circuitry has already failed, It's bad now.

Lasted 2 years, it's likely the problem.

Sounds like the replacement black one you have now I a Flight Systems PMD, which are good units. The same care applies to cooling on those.

J

[DennisG01]

I moved it behind the bumper. I kept the same one - I didn't change out to the spare, yet. It'll only take about 5 minutes so I figure I have nothing to lose.

Is there any other culprit that could cause this problem?

[Robyn]

classic PMD FAILURE

Get a fresh unit on there and you should be fine

As mentioned, once they stall once its already gone. From that point the stalling gets more frequent untill they stop altogether and will not restart.


Good luck

Missy

[andyh1956]

my '94 did this same xact thing after I had just serviced it, so I thought it was something I had done. turned out the positive feed wire from the right battery has a bad connection where the it had been spliced in. the p.o. had used a bullet union instead of a butt connector. go figure.

[DennisG01]

my '94 did this same xact thing after I had just serviced it, so I thought it was something I had done. turned out the positive feed wire from the right battery has a bad connection where the it had been spliced in. the p.o. had used a bullet union instead of a butt connector. go figure.

I'll double check that. I had replaced all cables (upsized, too) about 5 years ago so I don't think it will be that - but it's certainly worth while to check it. Thanks.

Thanks guys... and gal! I'm just glad to hear that the driver is the culprit and I don't have to start looking at other things, as well.