Injection pump timing numbers ??

[TCombs]

Why do Snap on scanners show the TDCO learn numbers on some trucks at 2.2 - 4.6 which is obviously wrong and others seem to be correct ?? Just recieved a new update for our scanner, (up to 2005 model year vehicles) and TDCO is still wrong on 99 K2500 ?? Actual pump timing and desired pump timing seem to be correct, but do you trust scanner for those readings or not ??

[gmctd]

The MT-2500's handle the data stream differently, with resultant displayed numbers offset - that's about right for standard timing, iirc.

Compare what you're seeing to a standard scanner, note the offset(s), and store that in your memory banks

[TCombs]

would you think that the desired and actual timing numbers are correct then ??

[gmctd]

Fairly certain Des\Act numbers are actually correct - it is the TDCO numbers that are offset by about 3.5deg (significant, or what?)