92RS,350TPI,5SP,ENG DETONATES ANY GEAR ANY LOAD JUST OFF IDLE. GOES AWAY WHEN ACCEL'D HARDER. KNOCK SENSOR CONNECTED W/NO CODES. HAVE SPENT HOURS ADJUSTING TIMING TO VARIOUS POSITIONS W/NO HELP. PREMIUM GAS HELPS BUT ENG IS A STOCK BUILD AND WOULD LIKE TO RUN REG. PUMP GAS. THIS IS A NEW SETUP AND PROBLEM HAS BEEN CONSTANT .

[This message has been edited by 92RSMESS (edited July 30, 2000).]

 

I had the same problem once and it turned out to be something called the spark control module that was located on top of the intake on the passenger side. This was on a truck though. It never threw a code until the module got hot from engine heat. I don't know for sure if your car has one or not but it might be worth checking into. I haven't a clue where it would be on a TPI. Hope this helps.

 

Does the car have valve seal problems? My '90 IROC does, and I had the same problem. Went thru all the sensors, etc.; no codes set, sanner data all within specs; but still had light to heavy detonation.

Finally decided that the only thing it could be was either a clogged cat, or a bad carbon problem in the cylinders. I had already had the cat checked at the local muffler shop, so that was eliminated. So I ran some top cylinder cleaner thru, and that helped greatly. It took several applications to get things back to normal, but it worked.

The stuff I used was called "Deep Creep". Its a foaming cleaner that you spray into the carb/throttle body, or in my case with TPI, its sprayed into the PCV hose so its sucked into the lower plenum/intake. You spray untill the motor loades up, then shut it off and let it soak for 5 minutes, then retart the car. It'll smoke for a while, but the stuff works. HTH.

Dean P.
'90 IROC Conv.
'99 Tahoe SS

[This message has been edited by racerx88 (edited July 31, 2000).]