Yep. DIsconnected those injectors...hope I didn't do a ton of damage by driving it like that. :-/

 

So if you think its a stuck valve this oil change might help.
Drain oil, remove filter drain it and put it back on. Add two quarts new oil and 1/2 quart diesel fuel. Drive normally. It removes a lot of gunk and might loosen up a stuck valve if its just stuck from gunk. Last time I did it I drove down the highway (mostly two lane with lots of curves and hills) 50 miles then back and drained it once it cooled down enough to get under there safely. It seems like a lot more than 2.5 quarts came out the second time.

 

Quote:

Originally Posted by tbugden

Okay guys I figured it out. Well, sort of. I found my IR temp gun and found that #6 and #8 cylinders aren't doing anything. They're getting spark and fuel (I swapped injectors today to be sure), but not firing.

#8 was the cylinder with lowest compression (105 PSI), but #6 had good compression (well, same as the others). Therefore, I'm guessing this is a valve issue or perhaps camshaft? Intake valves not opening all the way?

I'm quitting out of frustration with it today but I'll probably pull it all apart this weekend.

A few points to consider

1. When you ran the compression test, afterwards, did you add a shot of oil to the cylinder and try again? If the rings are worn out, usually compression comes back up..... If compression stays the same, its on the valve side of the motor. Keep in mind the heads are known to crack on these motors.... And EQ makes a improved design, as well as flow head for a very reasonable price. ($1,000.00 a set or a little less)

2. I would make sure the injector is firing..... What would make me suspect it would be 2 things. 1. This truck was orig. a V6 converted to V8..... 2. I would "think" if 1 or 2 cylinders are completely dead, idle would be rough, and there would be a dead miss in the truck.


FWIW I told you I got a Gtech..... Tried it out in my work van.... A 9200 lb (on the scales) E350 7.3 powerstroke diesel. 0 to 60 in an asphalt scorching 15.57 seconds!! I want to see what my dakota does.