New IP....timing set to 3.5 deg by dealer

[EscaladeDiesel]

The installation is complete, but my Suburban doesn't run that much better with the new IP, and it certainly does not have any better performance. It's also slow to start. All the improvements I was expecting to get from the NEW IP are not present. Is the 3.5 deg timing the place it needs to be? I am taking it back to the dealer tomorrow morning and would like to know what to tell them.

[garre1tt]

I have the same question.
I asked my shop to check the IP timing when I had it in for fuel tank problems. He said it was right on at 3.5. Therefore, what is the -1.5 that I keep reading about?
After reading Nigel

[EscaladeDiesel]

WOW...those are good questions, I hope somebody helps us out.

[Bigg R]

I've run into at least 2 other people besides myself that had start problems after injection pump install! My TDC offset was set at +1.94 instead of -1.94. I think most of the stealer mechanics just set the static timing, and as long as they run....out the door they go!!!! Have a reputable mechanic with a Tech II recheck your timing! Mine also had smoke/start problems so I bought a used Tech I and followed TDP advice for timing..Voila!! perfect starts every time even w/inoperable glow plug relay!!!
HOPE THIS HELPS!
BIGG R

[EscaladeDiesel]

Thats good info to have!!! NOW another problem is that I don't know of any mechanics in the Dallas area that can help me. Can I ask the mechanic @ the dealership to make an adjustment, will he be able to do that? Also, everyone talks about 1.? poss or neg. Mine is set at 3.5 why the vastly different number? Shouldn't mine be at 1. something?

[Bigg R]

3.5* is MEASURED INJECTION TIMING
-1. number is TDC OFFSET
3.5* is the factory spec for the MEASURED INJ TIMING! The service manual says that if the pump and PCM were removed at the same time to perform TIME SET. If your just timing the injection pump the computer already knows this value.Then you need only to perform TDC OFFSET LEARN this is where you will get your -1. value...usually by rotating the pump towards the drivers side!! Hopefully someone with a better grasp on this will chime in!
BIGG R

[charliepeterson]

Bigg R is right on. Try going back to the dealer and talking with the tech who did the work one on one. He's following the guide lines here. He did everything by the book.

What you want him to do can have an effect on the motor according to GM. Any warranty issues as well. Before going to these numbers you must have a pyrometer in the exhaust system. These new numbers can and will help the truck.

[Bigg R]

I knew either Charlie or JK would chime in on this one! A pyrometer is a necessity.I set my TDC OFFSET at -1.72,seemed like it didn't run as high on the pyro as -1.94 setting. I need to reset it to -1.94 now that I have an intercooler just to see if it makes any difference!!!!

BIGG R