2001 5.9, 2WD, 47RE, Stock...changed the TPS but still have an occasional misfire in OD under load after RPM increases misfire stops....could the new TPS actually be bad? bad PCM? Ground?, MAP sensor? Tx. for your reply.

 

How many miles on the engine? I've seen sloppy timing chains cause that when the engine can't spin up very fast.

 

208,000 miles on it...the engine seems to be very tight, quick starts good power etc.

 

I'd figure out the sweet spot where it happens (quite often, say, ~45mph in OD and tip into accelerator) and get it to do it as much as possible on a test drive until you get a pending code -- or if you get an actual code and CEL, all the better:
https://dodgeforum.com/forum/2nd-gen...surging-2.html

 

I'm assuming that this is a 5.9 gas motor, correct? If so, it should have a 46RE transmission in it. The 47RE is used behind the 5.9 diesel motor.

 

At 208K the chain may have been replaced. You can check for tightness by removing the distributor cap and marking the rotor position with something like soapstone. (Do NOT use pencil!) Put a mark on the harmonic balancer and then rotate the engine backwards by hand. Watch how far it turns before the rotor begins to move. If the engine rotates 10 or 20 degrees, you have slop in the chain. Now, if you know the chain was replaced, it won;t be worn already. It's also possible the fuel pump is starting to get weak. Has it ever been changed?

 

It's a 5.9 Cummins diesel...

 

Sorry, I should have stated 5.9 *** mins diesel.

 

yes, the fuel pump has been replaced and fuel pressure gauge installed...it seems ok.

 

it's a 5.9 diesel...tx