# 9 resistor and TDC Offset Learn

[Snakeyes]

Please correct me on the following :-

Changing to a PMD with a #9 resistor will make no difference in fuel rate unless you use a Tech2 or equivalent scanner and run the "TDC Offset Learn" program to allow the PCM to adjust the fuel rate and timing. This , if correct could be only applicable to 6.5TD's installed in H1 Hummers.

[DragNasty]

From what Ive read, The changes wont be imediate but the computer rechecks everything after every 50th key start, and it will pick up the change then.

[Chevylover]

From what Ive read, The changes wont be imediate but the computer rechecks everything after every 50th key start, and it will pick up the change then.


That's right !

Sven

[Snakeyes]

Thanks. Appreciate the feedback.

[TAZZ9963]

if you disconnect your batteries for and extende period of time (not real sure how long I would say a couple of hours at the most) will reset the learn process and it will learn on the first start.

[Snakeyes]

Even better. Thanks

[John R]

From what Ive read, The changes wont be imediate but the computer rechecks everything after every 50th key start, and it will pick up the change then. Thats right the computer will relearn itself!

[John R]

i believe the computer has a built in back up baterry that stores codes and settings in memory.My manual says to disconnect the batteries for about 15 seconds i tried this, but i found that i did not work for me.Then a buddy of mine told me about the built in battery thing and he told me to leave the batteries disconnected for about an hour or two so i did.I then reconected the batteries and Presto! it worked the computer now recognized the new resistor.

[rodincol@yahoo.com]

im new at this. i have a 93 1 ton dually, i read about this #9 res. and want to know how it works and if i can get 1 for mine. i have put in marine injs. and cold air intake.any info would be great

[johnodiesel]

The resistor is for the computer controlled injection pumps you have manual injection you are lucky and can just turn up the pump by the screw im unfimilar with that but look around others can help im sure

[grancito]

Yes, a number of us have posted the procedure. It's a long description, basicly, remove the top of the pump and some inside parts then turn the engine over to access an allen screw in a hole in the bottom. Tighten it a quarter turn.

[trukdoc]

...turn engine over with top off pump...turn it over by hand...