Pinging (detontaion)

[Stroker396]

Ok I have it running and generally it runs good. At first I was getting pinging at each new level of throttle. Now after several hundred miles I ocassionally get pinging. The mechanic sugested that perhaps there is too much advance. I dialed out a couple of degrees where it exceeded 40 although I have not had much of a chance to run it yet but I think it is still pinging. I will run it tomorrow and put it through its paces. Any ideas of what could be causing it would be helpful.

[VinceTrifecta]

If you still have knock sensors hooked up, they should be notifying the PCM of detonation, which would cause the PCM to retard the timing - so called "knock retard".

Do you have a data logger tool? If so, I'd check to see if you are getting any "knock retard". I'd also look for a lean fuel condition by monitoring the short term and long term fuel trims.

Also, have you done a compression test lately? If your cylinder pressure is excessive this could cause a problem too.

[singeon123]

i have the same problem...how can i retard it a few degrees???? i have no clue how???

[Stroker396]

I solved my problem 3 ways.

1. I got the lt4 knock sensor. Likely took care of most of it as it was false knock due to the roller rockers most likely.

2. I got bigger injectors. Stock would not supply the larger displacement engine.

3. With LT1 edit you can reprogram your PCM. Advance is one of the variables. Otherwise you can't with the exception of buying an MSD Optispark Distributor. I am told it will allow some adjustment up to 5 or 7 Degrees before it gets to the PCM. Both will run $450 or so.