6.5 bucking and idling rough, POOR MANNERS!

[PhattDaddy94HD]

I don't want to sound diesel stupid, but what is the OPS? It did kick a code at the same place on the way to work the last 2 day's. Light didn't stay on. I found that it doesn't have a engine to frame ground that I can find. All other grounds look good. Fuel pressure gauge is plumbed into the top of the fuel filter with Leroy's hollow bolt. Press. runs between 7-9psi except at WOT, then it drops to 3.5-4psi. That drop makes me think sock in the tank. Problem isn't at WOT, it is at cruise speed and at idle. I will get the ground done and get a scanner on it in the next few day's. I will report back with progress, HOPEFULLY! Thanks again

 

[ak diesel driver]

OPS= oil pressure sending unit. which supplies power to the LP and is a common failure on 94-95. But you have good pressure so it's not the OPS or tank sock. I would check filter as the top of the FFM is pre filter pressure. Also check the screen way down in the bottom of the FFM. if it's missing there is one more screen in the IP inlet that could be plugged.

Kinda sounds like a bad injector maybe loosen the lines going to the injs one at a time while it's running and see what happens. One other thing to check is to put a piece of clear tubing on the return coming out of the IP and watch it for air bubbles.

 

[WarWagon]

What was the code from the ECM?

 

[Burning oil]

X2 what Les said.
Grounds on pass side intake must be perfect. And you need to get that engine to frame ground hooked up.

The problem is consistant?

 

[JMJNet]

You don't need a scanner for a 94, you just need paper clip to read the codes.

The Technical Library has the procedure on how to do it.

 

[SmithvilleD]

If you don't have any luck diagnosing this, I've got the GMTD ScanTech that should connect to your OBDI truck & I'm fairly close, just north of town in Smithville.

I've been working 7 days/wk covering some folks vacation time, but will have a day or 2 off the Thursday after next, Aug 8 or 9th.

Agree on the suggestions above. Is the behavior happening very consistently?

 

[PhattDaddy94HD]

I do want to get with you on this problem. After looking at what you have done to your truck, I think you can probably shed some light on my problem. Leroy said the ground on the intake needs to be perfect, I don't see any grounds on the pass side rear of intake. I will install a Battery cable style ground strap from the motor to the frame this weekend. Also I will change out the fuel filter and check screen. All help is GREATLY appreciated!

 

[SmithvilleD]

I do want to get with you on this problem. After looking at what you have done to your truck, I think you can probably shed some light on my problem. Leroy said the ground on the intake needs to be perfect, I don't see any grounds on the pass side rear of intake. I will install a Battery cable style ground strap from the motor to the frame this weekend. Also I will change out the fuel filter and check screen. All help is GREATLY appreciated!

Be happy to help. Just PM me an email or phone # & we'll touchbase as I get closer to some days away from work.

Probably wouldn't be a bad idea to see if we could round up a meet of 6.5'rs local to the KC area sometime, as I think there are a few of us. We could probably also help one another out regarding used parts finds when we hunt the local Pick-N-Pulls, etc.

The grounds can't really be overdone, so that's not a bad idea. I ground (no pun intended) most of the engine/frame/firewall attachment points to bare metal & applied KopperShield (sp?) before refastening them. Don't know if that's truly necessary, but if we meet at my place, I've still got that product.

 

[Burning oil]

Ground wire/s on intake are just about 4-6" forward of where the dip stick on an auto would be (yours is 5 speed though).