I have been getting bad detonation on my car for a couple years now.
I have tried everything to try and resolve it and I am now considering that it may actually be a mechanical problem.
I think I can trace the problem back to when I rebuilt the engine last time, adding the GN1 heads and a comp 212/212 cam.
since then I have tried replaceing everything electronic in the car to find the source of the detonation.
I know the detonation is real by the numerous headgaskets I have hanging on my wall.
here's what I have tried to fix it.
Swapped all the below parts with known good parts
MAF
Coil/spark mod.
wires.
injector harness
I also upgraded fuel pump to a walbro 340
and went to 55# injectors.. tried numeous chips.
I also pulled my entire wiring harness to make sure the grounds were good (this was an unreal job!!!...never again)
added and relocated grounds.
finally I got fed up with it all and installed F.A.S.T. this weekend...and guess what???
same problem!!!!
I even checked my timing with a timing light.... when the ECM was requesting 20* I saw 20* on the light. (dialed it into 20* and read the mark on the crank pully)
it detonates at about 4500rpm everytime!!!!!
I was running a 50/50 mix of 114 and 93 octane 15 psi of boost and 18 degrees of timing.... the A/F ratio was below 12 and pulling a few percent of fuel.
the knock started at 6psi of boost... and the air fuel ratio was very safe. this is not seem tuning related.
now I have to consider that this is a mechanical problem.
my question is this.
can weak springs or an improperly ground cam cause this?
I am really fed up because it looks like I am pushing out the passenger's side HG again!!!
I have tried everything to try and resolve it and I am now considering that it may actually be a mechanical problem.
I think I can trace the problem back to when I rebuilt the engine last time, adding the GN1 heads and a comp 212/212 cam.
since then I have tried replaceing everything electronic in the car to find the source of the detonation.
I know the detonation is real by the numerous headgaskets I have hanging on my wall.
here's what I have tried to fix it.
Swapped all the below parts with known good parts
MAF
Coil/spark mod.
wires.
injector harness
I also upgraded fuel pump to a walbro 340
and went to 55# injectors.. tried numeous chips.
I also pulled my entire wiring harness to make sure the grounds were good (this was an unreal job!!!...never again)
added and relocated grounds.
finally I got fed up with it all and installed F.A.S.T. this weekend...and guess what???
same problem!!!!
I even checked my timing with a timing light.... when the ECM was requesting 20* I saw 20* on the light. (dialed it into 20* and read the mark on the crank pully)
it detonates at about 4500rpm everytime!!!!!
I was running a 50/50 mix of 114 and 93 octane 15 psi of boost and 18 degrees of timing.... the A/F ratio was below 12 and pulling a few percent of fuel.
the knock started at 6psi of boost... and the air fuel ratio was very safe. this is not seem tuning related.
now I have to consider that this is a mechanical problem.
my question is this.
can weak springs or an improperly ground cam cause this?
I am really fed up because it looks like I am pushing out the passenger's side HG again!!!