devrtyle2162
New Member
Hey everyone, I've recently picked up a 1995 L400 2.8 Diesel 4M40. Hoping you can help me diagnose a problem, I really appreciate the support these kinds of groups provide.
I seem to be having a Hesitation/Shudder/Cut Out while driving, especially under load. If I step quickly on the accelerator from stop, I notice lag, a decent plume of black smoke, and then were off. While driving, I notice this hesitation typically under more load, usually around 2-2500 rpm.
Engine starts up instantly when cold using the glow plugs (Yesterday was slightly warmer and didn't hear the plugs come on and it was a rougher start than usual). The previous owner of the vehicle had changed the Throttle Position Sensor recently to mitigate this issue with no success. I've checked the voltage of the new sensor with key on and have around 0.88V- 3.78V as you maually use the throttle and notice no dead spots. Seems like the Forums say 0.78V is ideal for these things, but I run out of adjustment to go any lower than 0.88V. It my understanding this being setup wrong would mean the car hunts for a gear at the wrong time. It doesn't seem like its hunting for a gear, it seems more like a cutout/hesitation.
The car has new batteries/alternator throwing out good voltage. I've read a bad diode can cause some stray AC to enter the system and cause problems like this, but I believe this has been ruled out.
Im personally leaning towards this being a fuel issue of some kind. Brand new fuel/air filter installed a couple weeks back (Had problem before and after new filter). I have noticed what looks like a very slight amount of weeping coming from the top of the injectors but extremely small if any, looks clean down there, no carbon buildups to see.
Im not exactly sure, where to go next. I've thought about taking the injectors out to clean them, or run a can of diesel purge through the lines, but could use whatever guidance you may be able to provide. Appreciate it guys.
I seem to be having a Hesitation/Shudder/Cut Out while driving, especially under load. If I step quickly on the accelerator from stop, I notice lag, a decent plume of black smoke, and then were off. While driving, I notice this hesitation typically under more load, usually around 2-2500 rpm.
Engine starts up instantly when cold using the glow plugs (Yesterday was slightly warmer and didn't hear the plugs come on and it was a rougher start than usual). The previous owner of the vehicle had changed the Throttle Position Sensor recently to mitigate this issue with no success. I've checked the voltage of the new sensor with key on and have around 0.88V- 3.78V as you maually use the throttle and notice no dead spots. Seems like the Forums say 0.78V is ideal for these things, but I run out of adjustment to go any lower than 0.88V. It my understanding this being setup wrong would mean the car hunts for a gear at the wrong time. It doesn't seem like its hunting for a gear, it seems more like a cutout/hesitation.
The car has new batteries/alternator throwing out good voltage. I've read a bad diode can cause some stray AC to enter the system and cause problems like this, but I believe this has been ruled out.
Im personally leaning towards this being a fuel issue of some kind. Brand new fuel/air filter installed a couple weeks back (Had problem before and after new filter). I have noticed what looks like a very slight amount of weeping coming from the top of the injectors but extremely small if any, looks clean down there, no carbon buildups to see.
Im not exactly sure, where to go next. I've thought about taking the injectors out to clean them, or run a can of diesel purge through the lines, but could use whatever guidance you may be able to provide. Appreciate it guys.
