Now that my 6.5 runs awesome, im helping my dad with his before he burns it ti the ground.
It is a 1994 6.5L that had a bad motor when he bought it, we dropped in a 6.2 block and added all the 6.5 goodies and headaches about a year ago. Its never really ran right but as of now it has a really rough idle like a misfire, no power (acceleration is very laggy), and at times it is hard to start when cold. What I have tried already is swapped the injectors, tried a good working PMD, replaced lift pump, fuel filter and vacuum lines. im not getting any codes and timing is almost exactly the same as mine.
Im thinking that the IP is done for, but Any ideas are very appreciated. thanks

 

Try chasing the grounds. M<y 98 was a bit of a dog, and after a lot of tinkering and trying anything I could think of I loosened and tightened the ground wire on the pump. Wow instant good power. Now it has a fresh wire added to the pump along with the original ground being cleaned up. I also cleaned the bundle of grounds on the back of the motor and added a fresh wire directly from the battery to the ground stud with the others. it is a basically free thing to do that can not hurt if it isn't needed.
pete

 

Ill give it a try. thanks

 

chased all grounds, added a few, im convinced that the ip is bad, its got a ton of white smoke and hard as hell to start. thanks for the input though

 

Sounds like a fuel issue. When is the last time the fuel sender unit has been replaced or inspected?

Could be a dirty sock, or worse, the wrong one.

Also, if one of those glow plugs is bad it might do some weird stuff. I accidentally left one wire off when cleaning the glow plug connectors and it ran like it was missing.

 

Ok so I dropped the tank, sock was a bit dirty but not as bad as i suspected, but replaced it since I was there, checked all the glow plug wires. After doing a ton of testing and research Im going to replace the IP, but I heard that the 94s have an oddball pump so I will dig in to it to find out if thats the case with this one.

 

I had a somewhat similar problem. At first my 98 6.5 ran well, then it became a little erratic, like out of tune, chug white smoke and finally stopped running smooth at all. I had no code, but I was underneath motor checking things out when I grabbed the sensor for timing and found the bolt loose. I undid the bolt and the metal bracket fell off the sensor. I bought a new one, put it in and the truck runs fine.

The name of the sensor evades me, bit it basically is an optic sensor that reads the four points on the flywheel so that it is timed properly.

 

I hope you replaced the sock with the right one. If it was a gas sock then you will have problems.

 

Update, replaced IP runs like a champ, now the trans is acting up. oh well time to dig in to that.

 

Crankshaft sensor.