AnimeFunTV

Hey all,

Just recently joined up, I know this is mostly a Camaro forum, but I have a 94 Buick Roadmaster Wagon however it too came with an LT1, I also just recently purchased a ALDL cable and Tunercat and this is the only best forum I found that has a great deal of experience with Tunercat & the LT1.

With all the information I was able to get my LT1 running smoother and 'Hopfully' get more economy out of it.

However there is just one question that I cant seem to find in search, is I know the EGR has a "EGR Spark Advance" which I had the entire table zeroed out and its running much smoother in the highway (I removed and disabled the EGR). When I turn on the A/C, I know the a/c adds a load on to the engine, but I cant seem to find any table or cell that controls the engine when the A/C is engaged. Whats happening with the a/c on, the pcm starts retarding the timing from about .1 to about 1.1 degree's on light throttle to mid throttle (acceleration from a stop sign to cursing on highway) Anyone have any hints on this issue?

bobdec

I will reply based on the F-Body PCM, assumption is the B-Body would work similar, but I could be wrong. The Idle Air Control keeps the engine running at the same speed when the a/c is on, there is a table called ' IAC offset for a/c anticipate Vs a/c pressure' that adds counts to the IAC as a/c pressure builds up. When you have the throttle depressed there should be no problem, the table really is for TPS closed situations. I have never heard of table that retards spark when a/c is engaged, not on the F-Body. Are you or have you ever seen any knock, the PCM will remember knock conditions and pull timing to prevent it from occurring. Are you running regular fuel, the low octane tables will also pull timing w/o knock count if the PCM thinks it may occur.