INTERMITTENT CEL ON 95 6.5 TD
 

I just bought truck about a week ago and it is giving me a cel when I let off gas and some times at idle and low throttle. It also is getting pretty bad gas mileage (about 13 to 14 mpg). I have just changed the PMD and did not install a resistor, the one I pulled had a #5 in it. May in install #5 at later date. Got any places to start? New to diesels so please give a location on stuff, haven't got manual yet.

95 CHEVY 6.5 TB 1500 4X4 VIN S
EGR DISABLED
4" STRAIGHT PIPE
COLD AIR INTAKE
PMD RELOCATED TO FENDER
NO RESISTOR IN PMD
REMOTE LIFT PUMP
233,000 MILES
RUNNING JET A WITH CETAIN BOOST AND STANODYNE LUBRICANT

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Sorry forgot codes. They have been different each time but they were 31 32. Cleared and now it is 33. I know they are EGR stuff. Were to start?

I am also having the same problem with the same fuel milage

Put the resistor in-it's required.
If you switched from black to grey have a look at Kennedy Diesels tech tips page for neutre instructions for the old resistor.

To check codes try the "paperclip code check".
General Motors Trouble Codes

The code definitions are not universal on the 6.5 so post your results here and we can help get you the correct info.

I will put the resistor back in thanks for that. Also the PMD is a black same as I removed Dorman. I got the codes out of truck using the paperclip. These should be for my truck below.

31 EGR Control Pressure/BARO Sensor Circuit Low (High VAC)
32 Exhaust Gas Recirculation (EGR) Circuit
33 EGR Control Pressure/BARO Sensor Circuit High (Low Vac)

DTC 31 - EGR Control Pressure/Baro Sensor Circuit Low (High Vacuum)
DTC 32 - EGR Circuit Error
DTC 33 - EGR Control Pressure/Baro Sensor Circuit High

Sounds like you lost a ground on the EGR circuits?

Ok I have put the resitor back in. To early to tell if that helped the mileage. Got any weak spots to start out in the ground for EGR? Relays maybe? Also the truck starts alittle hard have to give it just a bit of gas to get it going on it's own. Thanks for the help.

Hey racer

Is there a difference between the black or gray Stanadyne PMD's?

Yes there is a difference in the connector cavity and harness and resistor.
The grey PMD has gold plated pins and is supposed to have a gold plated harness connector.

The harness and resistor can be trimmed to become universal for both though,look at Kennedy Diesel's tech tips cfor connector interchange or the like.

Check vacuum pump

here is a vac line routing diagram for the truck if it has an EGR:
otherwise the ground just comes down to checking the wiring.