Injection pump timing keeps changing

[BB123]

I took my truck to the dealer and they keep setting the injector pump timing but everytime you drive it, it will change and be way off. The deisel tech was not there today and will be back tomorrow but I was wondering what could be making it do it.

[john8662]

Are you referring to the TDC offset changes?

If so, maybe it's because the tech forgot to do the "Time Set" after getting the appropriate value after a TDC learn..



-edited cause I need to go back to typing class

[BB123]

I'm really not sure all the guy who works the service counter said was injection pump timing and you are probably right this so called tech has laid out of work for the last two days so my truck is just sittin there. Thanks

[JohnC]

What is the symptom? Timing is controlled by the PCM. Unless the pump is moving or the stepper motor is bad (would set codes) then they're probably barking up the wrong tree!

[rjwest]

I had a technician??? try to set my 96(obd2) with a tech1 .Using 93-95 IP
timing procedures.
It became all screwed up... He would move the IP than retime it, and get a way out reading,

Finially, I told him to tighten it up and I would do it myself.

2 hours , Finished & Correct,

I think the TECH.???? was forcing a TDCO set with the coolant to low,
, IP advanced?, anyway, each time he would make a Pump adjustment
( rotating the IP) he would get TDCO's that did not make any sense.

I have found that clearing the TDCO with the keyon/keyoff procedure
and than allowing the PCM to set the TDCO worked better than any other
procedure, A TDCO reader is only the required tool.

[65TD]

When the TDC learn is performed the value is stored in the PCM.

Is this stored value getting lost?

What is it doing after you drive that makes you think it has a timing problem?