1996 - 2002 GM 6.5L Diesel Stanadyne Injection Pump Timing Adjustment TDCO Procedure (Chevy & GMC)

In this video we will go thru how to adjust the Stanadyne DS4 diesel fuel injection pump timing mounting position on the GM 6.5L diesel engines. This particular process is only performed after a out of specification Top Dead Center Offset (TDC Offset or TDCO) relearn result has occurred. Physically adjusting the injection pump is necessary, in this situation only, in order to bring the TDC offset back into GM shop manual factory specification. A worn timing chain can introduce as much as 4 degrees of timing variance. This series pump was used in Chevy, GMC, and Holden trucks of the GMT400 or old body style (OBS) variety as well as vans from the years 1994 thru 2002.

The engine illustrated in the video is the 1999 version of the L65 Turbo Charged VIN code F layout, but the timing adjustment procedure applies to all 6.5L engines with this series of electronic injection pump. The TDC offset procedure shown with the Tech2 scan tool may vary for pre-1996 vehicles though. A Tech2 scan tool and three specialized wrenches shown in the video will be required to perform this procedure.

NOTE: The TDCO is NOT the procedure to use when timing a new or used replacement injection pump, or even when reinstalling the original injection pump. You only perform this TDCO Learn procedure ONLY when:
You replaced the PCM (new or used but different than original)
You replaced the crankshaft sensor (new or used but different than original)
You replaced BOTH the PCM and the crankshaft sensor (new or used for either but neither original)
You replaced the entire engine (rebuilt or used where core engine components are not the originals)

The timing procedure for when you replace the injection pump is called TIME SET and I cover that in a different video here -    • 1994 - 2002 GM OBS Trucks 6.5L Diesel...  

WARNING: The torque value for the upper intake manifold crossover in the service manual page shown at 44:07 is WRONG. It's a typo on that page only, and should say 17 Foot Pounds!

The eBay, Aliexpress and Amazon search links below are paid links, for which I may be compensated and earn a commission, if you choose to buy the parts and tools shown in this video thru them:

There are several sources for the specialized wrenches including Kent-Moore J-29872-A, Kent-Moore J-41711, Kent-Moore J-41089, OTC 6087, OTC 6083, Sunluway SY-J-29872-A, and Snap-On S6133: https://ebay.us/Vbtqa2 or https://amzn.to/3qtV8ol

If you're looking to buy your own GM Tech2 scan tool: https://ebay.us/7bm2xX or https://s.click.aliexpress.com/e/_DlS...

For the GM C/K type service manual I was using in this video: https://ebay.us/zNZ23T

And if you're looking for the GM 10137537 intake manifold extension gasket: https://ebay.us/wJI5fs

And if I've saved you some $$ here, consider some coins for the coffee tip-jar! https://ko-fi.com/drshock

1994 1995 1996 1997 1998 1999 2000 2001 2002 Suburban Blazer Tahoe Sierra Yukon Silverado Cheyenne

Chapters
0:00 - Problem overview
0:37 - Engine shroud removal
1:47 - Intake manifold extension removal
6:27 - Injection pump mounting location
8:21 - Special tools & procedure
16:42 - Adjustment of injection pump
26:06 - Scan tool TDC offset relearn
31:32 - Post adjustment overview
40:00 - Intake extension and shroud reassembly

#drshock #65diesel #chevytrucks

Disclaimer: DrShock, the alias for the human content creator for this YouTube channel, is not responsible for any damages, injuries, losses, or liabilities associated with any repairs, upgrades, or maintenance performed on yours, or any other, vehicle whatsoever. No warranty, express or implied, is made as to the accuracy or completeness of any information provided within this channel. Viewing and using the “as-is" information of this channel is totally at your own risk. Always wear personal protection equipment and follow appropriate vehicle manufacturer service manual guidelines with original manufacturer parts only when performing any repairs, upgrades, or maintenance upon any vehicle.