The Stovebolt Site Forums The Shop Area The HiPo Shop Late model engine question

Plan is to re-body this '94 K2500 4wd 454ci Burb with a pre-75 Burb. I'd like to get it registered and use it tow home its new body but in California it must pass smog when it changes hands. Had it pre-tested and they said O2 sensor and cat so I did that. It failed for high NO. Took it back to the pre-smog guys and they said the harmonic balancer spun so it wouldn't time. Intalled a new balancer, made no difference. It runs well, advanced way off the timing tab. When I try to time it at 4 degrees, it runs poorly. Is it possible for an engine with 135k miles to be out of time that far from a stretched chain? Would it be running at all well if it had jumped a link? Any other thoughts what can be causing the timing to be so far off the mark? It's a great donor vehicle and I'd like to use it till I find a Burb to do this project. Thanks, Don

While the distributor is driven by the cam, the ignition timing is set to the crank position, and controlled by the ECU. I think there's a "procedure" for setting the initial timing at or near TDC, and then letting the ECU do it's thing, but I'm not familiar with the specifics.
I don't think 135k is so many miles that you have to worry...yet. If it had "jumped a link" your valve timing would be off, but this is highly unlikely.
Your ECU may be the culprit.

cm

Ok. Now I don't understand. I disabled the distributor ignition by disconnecting the brown and black wire and set the timing at 4 degrees with my old fashioned timing light. . Is there something else I'm missing here. Please forgive my ignorance of computer controlled stuff.

Distributor was off a tooth...where were all you technowizzards?