I have a 94 Blazer with a 6.5TD in it. It's all stock except a PMD relocation. Fuel filter was changed less than 1k miles ago. Oil just changed. Batteries are good. New OPS.

Anyway, it's intermittently stalling and difficult to start regardless of temp. SES light is on and when it goes off the truck starts like nothing is wrong. It's throwing codes 32, 33, 35 and 36. I have been screwing around with this for quite sometime. Sure seems like it's an electrical problem but I sure can't find it. I think the only things that I have not ruled out are the IP and PCM but I wanted to come on here and make sure I wasn't missing something obvious before I go replacing the PCM or IP. Any advice is appreciated.

-Garret

 

DTC 32 - EGR Circuit Error
DTC 33 - EGR Control Pressure/Baro Sensor Circuit High
DTC 35 - Injection Pulse Width Error (Time Short)
DTC 36 - Injection Pulse Width Error (Time Long)

Wiring problem with EGR.

PMD's seldom throw codes but those are ones that sometimes come from a PMD?

Any fuel laying in the engine valley?
The water in fuel sensor and fuel heater O-rings are common leak points.
Have you replaced the IP fuel return line with clear diesel rated hose and watched that line with the truck safely parked and idling?
Watch there for bubbles-they indicate air getting in the fuel and might explain the symptoms?

Might want to try eliminating the PMD extension harness by moving the PMD/heatsink combo to where it can connect directly to the IP harness?

 

I verified that the EGR itself was working correctly but have not checked the wiring. Will do that shortly.

I have a backup PMD and it doesn't seem to make any difference which one I use.

No

I don't see any signs of leaking around either but will check more closely.

It's just the factory line. Sounds like a worthwhile mod regardless will probably do that tomorrow or tonight if I have time.

Tried it, made no difference.

Thanks for all the tips, I am going to go work on it right now. Hopefully will report back soon.

 

If you detect air in the fuel it will most likely be entering between the fuel level in the tank and the lift pump.

Another thought on codes 35,36 could be a bad OS electronic noise filter,it is in the OS harness and can be removed and the harness plugged directly into the OS,but you will need to get enough ferrite core from radio shack to put a piece around all the OS harness wires.