My mechanical Cummins 8.3 has "stalled" three times in the last 1,000 miles for no apparent reason I can figure out. It suddenly stops producing power while driving along on the flat and level in moderate weather between 50 and 60 mph. The engine suddenly doesn't respond the the throttle but the transmission continues to keep the engine turning over as it shifts down as the coach continues to slow down until I pull over and stop. At that point the engine is dead. I turn off the key, turn it back on and it starts right up. A moment later we're back in traffic, running just fine. And, it will run just fine all the way home.
During this "stalling", the instrument panel is normal with no red lights. The oil pressure, engine temperature, transmission temperature, etc are all normal until just before we come to a complete stop and then the red lights come on. In fact, everything looks completely normal during the stalling incident, only the engine isn't producing any power.
At first I thought it might be a plugged filter, but a half hour or more before and after these incidents, I was at wide open throttle for several minutes without so much as a hiccup. I think that may also rule out a fuel pump getting weak. My fuel tank was also over 1/2 full at each of these three incidents. The engine was completely warmed up and not overheating.
I thought about a low oil level and some kind of low oil cut off, but the oil level is normal.
I thought about a relay or solenoid failing, but wouldn't they fail at startup and not after the engine is running? If it was a loose wire at the ignition key, then the instrument panel would also go dead. Everything stays on during the "stall".
Any suggestions on what to look for?
Holiday Rambler Navigator DP, Hummer, and Honda VT1100C Shadow
Let me know what you find, mine did the exact same thing last time out. only the engine never quit, it would idle, but not respond to throttle. and it had a yellow engine light. Shut it off, check engine all is good, start it up and drive away. no more problems.
What the H-LL was that?
It happened in the little town of Gold Bar Wa, highway 2, we had just run Stevens pass both ways no problems.
I have a '98.5 5.9L ISB...and about 6 months ago, it started abruptly going to idle. At first I thought the engine had quit. The engine never actually quit. It just went abruptly to idle...with me still mashing down on the accelerator. I would push the clutch in...jiggle the accelerator pedal...and miraculously the engine would start working again.
Anyway it threw a bunch of codes...but what I wound up replacing was the TPS (Throttle Position Sensor). I got all kinds of codes for the turbo being overboosted too...but I think that's because the m.p. sensor detected a high pressure while the throttle was commanding idle.
I found a replacement on eBAY...ordered it...it took about 30 minutes to install and reprogram the idle setpoint... and it's not happened again since.
I think my Dad's Southwind DP is doing the same thing...I'll have to see if replacing the TPS on his Motorhome will fix the problem.
Like you say...the fuel system could be to blame too. Hopefully your injector pumps not failing. That would be a bit more expensive than a TPS for sure...
Since you mention it is a mechanical engine, no computer or electronics, I would look at the fuel shut off solenoid. It is normally closed until energized. You are intermittently loosing power to it, or it is going bad. If you look, there should be a screw on the side of it. If you should loose power and it won't start, you can screw it in and override it. You will have to unscrew it to shut it down though.
2010 Ram 3500, Crew Cab, Long bed, 4 x 4,Dually, Lights & Siren!
I appreciate your suggestions and comments. As for checking the codes, this is a 1993 mechanical Cummins that doesn't have a computer.
That fuel system solenoid sounds like a possible cause, so I'll replace it as a precaution. Just where is it located? I have a number of relays in my electrical service bay so that would be the logical place but I actually have no idea which one it is or where it is.
Fishinghat wrote: I appreciate your suggestions and comments. As for checking the codes, this is a 1993 mechanical Cummins that doesn't have a computer.
That fuel system solenoid sounds like a possible cause, so I'll replace it as a precaution. Just where is it located? I have a number of relays in my electrical service bay so that would be the logical place but I actually have no idea which one it is or where it is.
This connection is on the back of your injector pump. It was common for the connection to get loose on 5.9's of that era (mine included). Pull it off and if it seems loose, squeeze it together gently with some needle nose pliers before pushing it back on.
Scott, Grace and Wesly
2003 Dodge 3500 4x4, 6 speed Cummins (lightly bombed),
2004 Forest River 25RKS many, many mods.
H0NDA eu2000i
ScottG, I'll do that. Thanks. I've never looked for the injector pump, but by trial and error, I'll probably be able to find it. Cleaning and securing the connection would be good preventive mainteance even if it isn't the cause.
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