Engine Shutdown Without Warning

[JIMNJAN]

Today, at highway speed, our Cummins 8.3 mechanical engine suddenly shut down with no warning. No buzzers or lights – the engine just suddenly stopped. All the gauges were in the green. After safely pulling to the side of the road and catching our breath; restarted and saw nothing unusual – temp, oil, etc, all normal. We continued driving without incident for the remainder of the trip. This has happened to us at least 5 times over the past 2 years. It always happens at highway speeds under normal conditions; both with and without cruise control being on. We have had extensive diagnostics run at two very good shops and nothing has been found – no one can duplicate the problem. Has anyone else encountered this sort of problem? Engine never misses a beat otherwise.

[racer0624]

I had a mechanical 8.3 and the Spartan MM chassis of that era were known to have an electrical problem with the fuel solenoid. Mine sometimes wouldn't open so the engine couldn't start. My solution was to have a bungee cord handy to manually hold it open. Of course turning the ignition key off wouldn't shut the engine down. I had to release the bungee cord and close the solenoid. As this is rare occurance for you I'd suggest looking into a new fuel solenoid valve.

[jDavid]

My 95 Eagle had a like problem. After a years worth of troubleshooting it became apparent it was electrical. When ever the engine accessory bus power would drop below 10 volts DC, the engine would shut down. The coach would start back up with no problem. I had several problems, first was the alternator, it was intermittent, most of the time it would put out 14 vdc, but on several occassions it would drop below 10vdc. Finally replaced it and thought I had fixed the problem but then one day when I returning home from a service visit, I turned on the dash a/c, the engine shut down (it was not the load of the AC system but the fan). Anyway I connected four Voltmeters to the control solenoids under the hood. One solenoid had 14 volts going in and 12 vdc coming out. Removed and replaced and all has worked great. Oh, I opened the solenoid because I am curious, it was very corroded inside and was not making good contact,

[sgb]

The same problem happend to me in a rented Bounder a few years ago.
I now own my own Mountain Aire by the way.
Anyway, it was the fuel pump.
As long as we drove on a flat road it was fine. The slighest upslope hill would cause the engine to cut off. The fuel pump was able to sustain a flat road, but not a small slope. SGB

[VACMAN]

This probably won't help, but it is worth a try: A friend of mine had the same problem. No one could figure it out. Then one day we were looking at it with the engine running, rear cover was open, my friend just touched a switch, (didn't turn it, just touched it) and the engine died. But it started right back up. I don,t know the name of the switch, I was told it is back by the engine to kill everthing. Anyway I talked to my friend later and he said he had the switch replaced, and never had a stoppage again..Just a thought. VACMAN