1996 chevrolet 6.5l turbo diesel shuts off while driving

For about a year now, when driving the engine will turn off and startup backup. Sometimes have to pull over and start it back up. I have changed the lower fuel pump, fuel filter and checked all grounds. There are no error codes being thrown.

Has anyone seen this? Any ideas? Garages have not found the problem and I am tired of wasting money.


The most common reason for a diesel to stop running mid-stream like that is b/c of lack of fuel. So your idea to replace the lower fuel pump and fuel filter was a good bet. A faulty injection pump could be the reason it is still doing it though. That’s my guess, injection pump. Other ideas, debris in fuel tank intermittently creates a clog, clogged exhaust system, engine air supply clogged.

thank you for the reply. BTW, I didn’t mention that this happens intermittently. It can go weeks without doing it, but sometimes everyday for a few days.

hmmm … Intermittent symptoms like that makes me want to discount the injection pump idea. I wouldn’t start w/that as the prime suspect anyway. Might be worth it to do some more experimenting with the lower fuel pump, especially its power supply voltage. Do you think you could figure a way of monitoring the voltage at that fuel pump as you drive? Might provide a clue. Could be a fuse, connector, relay problem. I had a gasoline VW Rabbit at one time that had weird intermittent symptoms like that, where it would just shut off as you drove down the freeway, for no apparent reason. Dead as a doornail. Wait 30 minutes on the side of the road, started up and worked fine. Turned out to be a faulty fuel pump relay and a burned out relay plate, lowered the voltage to the pump to the point it ran out of gas. The intermittent nature was b/c the connections inside the relay plate would heat up, change dimensions, and electrical contact would be lost.

thanks. All good suggestions. Have seen posts else where that it could be crankshaft power sensor or pmd. Will give your ideas a try.

thanks again

Crankshaft position sensor on a diesel? — hmm … It’s a critical sensor on a gasoline engine, but on a diesel it seems like its main function would be for safety purposes; to tell the engine computer whether the motor was running or not, and if it wasn’t running the computer would shut off the fuel supply; e.g. to prevent fires in case of an accident for example. that might show up if you monitored the fuel pump power supply voltage.

Does your truck’s computer post diagnostic codes? If so, what do they say?

Truck’s computer is not showing any error codes. Thanks George for your time. Its appreciated.

My Blazer ('97, 230K miles) died last winter. Had some “hiccups” prior to dying, where would almost die, but come back to life. Thought it was the fuel pump; had a bad fuel pump on another car, same symptoms. I let my “guy” look over the Blazer. He found a spark while starting/running. Discovered that it was indeed the fuel pump, but not the pump itself - the insulation had rubbed off the power wiring to the fuel pump and it was intermittently shorting out due to normal vibration. He ended up wrapping the bad spot with electrical tape; no problems with this until I traded it in last fall.

Sorry for the long explanation, @nmdiesel, but bottom line is to check your wiring. It might be as simple as that.

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thank you for your reply boilerengtn. I’ve been leaning towards electrical being the issue. Will trace wires from and to pump.

thanks again

Not sure about a Chevy, sorry, but I have an International Diesel that will need a Camshaft Position Sensor when it starts doing that, and it will do it without showing any error codes most of the time. I replace the sensor, and all is good for about a year.

Not a lot of help, I realize, but this could be a possibility.

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thank you for taking the time to reply. I’ve seen some posts on other forums that say cps could be culprit. Its one of the things I am testing for over the next few days.

thanks again