1995 Ram -- 1500 -- 4x4 -- 5.9 L -- 200,000 miles

The engine shuts off while driving. It started doing this at highway speed and has progressively gotten worse. Now, I can't get above 20-30 mph. When the problem started, it seemed to only shut off when you let off on the accelerator, then progressed to doing it only while under a load like when accelerating, then when you got to 40 mph, then 35 mph and now you can barely reach 20 mph. When it shuts off, it acts like you just reached up and switched the key to the off position. (You loose the tach and speedometer reading.) The truck is bone stock. Normal parts have been replaced over the years(transmission, fuel injectors, fuel pump, etc.) but no upgrades and I am the original owner.

Since this problem started, I have replaced or eliminated a lot of parts. Some parts were replaced and some were unplugged. Those I unplugged caused the engine to run rough, butI was still faced with the same shut off. I forgot to mention, when the engine shuts off because of this problem I have to turn the key to the off position for a couple of seconds before it will restart. As opposed to pulling the coil wire or pulling the ASD relay when it will restart without turning the key off before restating.
There Are no codes. It will idle all day with no problem.

IdleAir control -- unplugged nochange
Throttle position sensor-- unplugged no change
MAP sensor-- unplugged no change
PCM/computer (60 pin connector) -- replaced no change
Ignition switch -- replaced no change
AsdRelay -- replaced no change
AllRelays -- replaced no change
Coil -- replaced no change
Cam position sensor (in distributor) -- replaced no change
4wd switch(on axle) -- replaced trying to fix problem with 4wd light staying on
Checked fuel pressure -- 45 psi with key on... Held at 35psi for over 5 minutes ... 45 psi under driving condition.

Folks, I'm stumped. If it was starving for fuel or not getting enough air, it would stumble before dieing. But it acts like you have switched it off and want start again until you switch it off for a couple of seconds. Then it will fire back up with no problem.

Does anyone have any suggestions? (Other than gasoline, a match and a call to the insurance company...ha ha... Or does anyone know what can signals sent to the computer can cause it to shut down. If you just want to ask questions, that's fine. At least it will keep the mind working in the right direction.

 

Clogged cat maybe, hit the cat with something and see if it rattles.

 

how about crank position sensor. passenger side, top of bell housing, sort of behind the oil filter.

when the pcm gets no signal from crank sensor that the engine is running, it trips the ASD.

 

Thanks for the ideas. the cat seems to be okay a far as I'm able to tell and I guess I'll have to stop putting the crank sensor on the back burner. From looking at the manual I'm too fat to get my arm in there, so it looks like a trip to the mechanic. I just kept talking myself out of the crank sensor since it is an interment problem. I had always thought it was either good or bad. But from further reading I'm told it could cause my problem. I have always said, "If you don't learn something new every day, it's only because you weren't paying attention".

Thanks for the help so far and if anyone has any other ideas, don't be shy. Speak up.

Thanks,
Jeff

 

Crank sensor looks like a really good candidate, given your description. Make sure your mechanic gets the part from the dealer though, as these trucks don't like aftermarket sensors.

That said, where did you get your cam sensor from?