Does the pmd resistor make any differance in the running or performance of my 94 6.5 turbo diesel? The diesel pump shop in Evansville, In. said it makes no differance witch one you use or if you use one at all. I kinda think Its strange that they make them from 1 to 9 and dont make a differance.:cool:

Thanks to everyone that gave me input on my chevy 3500 6.5 Turbo Diesel. They, the chevy dealer or the pump shop would still have my truck if I hadnt went and told them they had the wrong pump on it, thanks to your comments.

Resistor will make any only the slightest change to fuel delivery. (Only a few mm3). Can't tell the difference from the drivers seat.

Oh, yeah, it's a must-have item. Computer looks for it, every-so-often. No resistor, throws a code.

I kinda think Its strange that they make them from 1 to 9 and dont make a differance.:cool:


Not to nitpick but it is 1 to 13 but almost no1 can get the 10-13 ones now and no need for them unless you are maxxing the 6.5L and even then you don't need them.

Details on the 10-13?

In slight adjustment, I've seen various references to a 12% change in max fuel delivery from resistor #1 to #9. Stock is supposed to be a #5. Each resistor step was about 0.5mm3 in max fuel delivery volume.

On what I've read. the key is Max fuel delivery or full power. Light loads, may not show a difference unless you have a heavy foot. Towing you might notice the differnce in acceleration, and mileage between resistors.

The PCM will set a P1218 code without a resistor and if the value is too big (ie #13 used in military engines)


For the $15 to $25 for a resistor, I has looking at going back to a five or lower for daily (light load) driving and mileage. (Limit the fuel on the occassional motor mash, might save a few $$ on fuel)

I have a slightly different understanding than jmiller but will defer to his values. My understanding was that :-

Each resistor step changes fuel delivery by approximately 1.5%. The resistor directly affects the injection volume strokes (approximately 1 mm³/1000 strokes on a stock base of 64 mm³/1000 strokes).
The effect on actual performance is minimal and useful only in fine-tuning the performance of a highly modified turbo diesel.

A #10 resistor would be in excess of 81400 ohms and would likely set off codes.

At least the the math on the precentage change works to be the same. 8 x1.5% is 12%. I recheck and you are correct, I miss quoted the volume change.


Regards