'02 GM 6.5 Turbo

[pafixitman]

Engine will not go below 2,000 RPM at idle. Jumps to 7,000
Engine is a 2002 GM 6.5l turbo diesel.

Any ideas / help is appreciated.

Guy bought my MB and came down from the Rochester NY area. Called me about 2 miles from my house. Changed the fuel filter and things seemed to clear up. Sold the car, said goodbye. Just got a call from him. He is in East Berlin, PA and said it will not go below 2,000. He is getting a room for the night. Any ideas would be appreciated.

The engine is a crate motor replacement in a mid 90's K3500. 5 spd. He is running filtered WMO but when the truck started acting up, he switched to
#2.

Too many sensors under the hood for me to help! Post replies as he will be calling me back. PM numbers if it is ok for him / us to call you.

 

[pafixitman]

Truck is still down. They left it at a farm in East berlin, PA. Drove the MB back to Rochester. Good news is that my old MB made it back with out issue.
He runs the WMO thru a centrifuge and takes it down under 10 micron.

Any thoughts???

 

[Mike]

Didnt the 6.5 still have a real live throttle cable?

 

[pafixitman]

Not sure. That was the first 6.5 I was up close and personal with! The filter would be the first thing I by pass with after market. $28 for a drop in paper element? ***!

 

[Exekiel69]

I would check the throttle cable too, if it has one. The only way to rev up the ip on a diesel engine is giving it more fuel as far as I know. Did he turn up the fuel on that engine at any time? The wmo mix is rich compared to regular diesel so I would think it could actually rev an engine higher (don't quote Me on this) but not 2k rpm at idle.

 

[Mike]

I've done some digging and see that the 6.5 is a fly by wire, there is a set of resistors on the side of the pump (pump mounted drivers aka PMD) that can foul up. I wonder if the rig runs better once its cooled off?

 

[dieseldummy]

I would guess maybe the WMO finally got the best of the optic sensor. It's on top of the IP, and you probably have to pull the upper intake off to get at it. I'd try unplugging it and seeing what happens. It will start with it unplugged after and extended cranking session and run with default values. Other than that I'd say the WMO finished off someting else in the IP.

 

[pafixitman]

I did some google over the weekend and saw the OS did not like WMO. Mike might be onto something because, yes it does behave after it has sat for a bit. I'll pass the info on.

It is a bit odd because on one hand I think that I do not "owe" him any help, nor is it my concern. On the other hand I know how I have been helped in a time of need when I was out of town and it makes me happy to do the right thing and try to assist him. Thanks for the replies. I have not seen Calvin around, I was thinking he may have some experience with these motors.

 

[Dsl_Dog_Treat]

I've done some digging and see that the 6.5 is a fly by wire, there is a set of resistors on the side of the pump (pump mounted drivers aka PMD) that can foul up. I wonder if the rig runs better once its cooled off?

Yup, fly by wire PMD= poor mans design.

Normally they'll either just stall out or won't start at all once they get hot.
Most of the replacement PMD require relocating it off of the IP to a cooler location.

The OS's aren't to tolerable to alternative fuels and that too may be an issue.

I have not seen Calvin around, I was thinking he may have some experience with these motors.

Yeah Joe, he's like the Chebby guru. Have called on him a few times for my neighbors truck issues.