Questions and Answers
Jerking Diesel
Q. Vince, I have a 1994 GMC 2500 6.5 liter turbo-diesel VIN F four wheel drive. We just put a brand new GMC motor in and have 500 miles on it. All the glow plugs, sensors, and injectors are new. Our problem is that when driving down the road it starts to buck and jerk than dies every now and then, sometimes it goes back to running fine for a few more miles.
We have taken it to several dealerships and mechanics and have had the computers on it, but they can not seem to find anything wrong with it. I am out of answers and fed up with it. What could you suggest that nobody else has?
Brad
A. There's three things that can make a diesel exhibit these symptoms. One is a bad fuel pump, a clogged fuel filter or air in the injection system. I would replace the fuel filter first and I think that will fix you up. If it is a fuel pump (which is part of the injection pump) you're looking at major bucks to replace it.
To bleed the fuel system:
- Open the air bleed valve on top of the fuel manager/filter.
- Connect a hose to the air bleed valve located on top of the fuel manager/filter and place the other end of the hose into a suitable container.
- Remove F/SOL fuse from fuse panel.
- Crank the engine in 10 to 15 second intervals until clear fuel is observed at the air bleed hose (wait for one minute between cranking intervals).
- Close the air bleed valve.
- Install F/SOL fuse in fuse panel.
- Start the engine and allow to run for five minutes at idle.
- Check for fuel leaks.
Other than that, there's not much else that can go wrong. There is no ignition system to go bad and the glow plugs only come into play when you start it.
I experienced these same symptoms on my trip to new Jersey. When I hit the mountains in Pennsylvania it started doing the same thing. A new fuel filter cured the problem instantly.
Additional Information provided courtesy of ALLDATA
