1992 Chevy Silverado V8 Two Wheel Drive Automatic
What would cause the engine to want 53 degree's of timing to run just ok. It is a 355, the original block with trickflow heads and roller cam. It also has a 4bbl 4 venturi aftermarket tbi. The cam has been degreed and is timed perfectly. When I set initial timing (with wire unpluged) and then plug it back in it runs at about 22 degree"s advanced but will not run worth a crap. All sensors are new. Distributor is also new (stock). I have even replaced spark advance module to no avail. Massive tuning done by Lt1pcm. Com to no avail. With wire pluged in I can advance it to about 53-60 advanced and it runs much better. It seems as if the spark timing is malfunctioning. As I said all sensors are new and nothing abnormal coming accross data log. I am able to log the ecu but we cant find anything a miss. Is there any way to work on distributor to fix this or does this sound like tuning issue. Compression check done and all is well. 50 psi of fuel pressure with no drop off. How do I fix this problem? Has anyone ever had this type of problem before? Please Help. I am a pretty good back yard mechanic but this is beyond my comprehension. How could I just convert over to carburator or can i?
have the same problem?
Friday, February 19th, 2010 AT 3:04 PM