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Aryeh Levy
08-14-2005, 17:19
I took my truck to the stealership - i asked for injection pump timing @-1.5. They told me that the computer learns on its own what timing is best, and that it couldn't be set. ??? How do i get it set? Can i do it myself by ear, or power? or should i take it to a stanadyne service center? Best Advice? My engine is real quiet, only slight rattling on one or two cyl... i'm guessing its between 0 and 3 degrees after TDC

rjschoolcraft
08-14-2005, 18:06
There are two specific timing procedures. One is considered primary while the other is "backup". The backup procedure is the TDC Offset Learn. This offset is between the PCM "thinks" the piston is at TDC and when it actually is. Both timing procedures may only be done with a TechII. Factory spec for desired timing is 3.5 deg BTDC at idle and TDC Offset between 0 and -.5 TDC. I set mine at -1.94 which yields 8.5 deg BTDC advance at idle.

The dealer mechanic was misinformed...

Bigg R
08-15-2005, 10:44
I timed my brothers 98 with a Tech 1A last week timing was set at 3.5 BTDC/TDC offset @ -1.5. After you turn off time set, the number will jump to a larger figure. It can be done,even by a dumb hick like me! :D

MJEasly
08-15-2005, 12:14
So, if you set the base timing to 8.5 BTDC the offset will learn to -1.94?

Aryeh Levy
08-16-2005, 18:13
Anybody else do the 1A timing?

The dealership said there was a Learn procedure that automatically happens every time the battery completely loses power, and relearns when coolant reaches 170.

Anybody know a really good 6.5 shop near Washington, DC?

GMC Hauler
08-17-2005, 17:44
Don't forget, those timing procedures can now be done with the Autoenginuity scantool.

azblazor
08-18-2005, 06:30
Originally posted by GMC Hauler:
Don't forget, those timing procedures can now be done with the Autoenginuity scantool. Could you email me at mwhiting@apsc.com? I would like to know a little more about the Autoenginuity scantool. I also looked at your project write ups on picturetrails. Great job, very well done. I signed your guest log.