Is it possible to cause detonation at idle? I was adjusting the idle fuel through my pfs last night and realized i was reducing fuel...the car started bucking REALLY bad at 300rpms....is it even possible to cause detonation from a too lean idle?

 

I would think not, it probally was sputering trying to maintain idle. 300rpm is a really slow engine speed.

 

You probably could if you did it on purpose...

 

well my idle is set at -22% fuel...i dropped it to -28%..i never died or made weird popping noises or anything...it just started bucking....everything seems fine now though...same vac

 

150 shot at idle?

 

yeah, it's not burning anything if it's bucking.

 

Whatever floats your boat

 

detonation usually only happens at higher load; higher combustion pressures.

I can't see it happening at idle.

 

You were probably just starving the motor of fuel. 300 rpms is about 600 rpm too low on a ported motor anyway......

 

I dont know about the FD, but I have a friend that popped his motor in his STI at idle.

 

If the motor has no fuel it will do exactly that.

 

I really doubt it. Det will damage the engine if the pressure spike at ppp exceeds the engines parameters drastically. If you lean it out ie past stoich at idle i would expect to see the idle get lumpy as the engine is starved of fuel and struggles to combust untill it stalls.

Scott

 

If there is no fuel, detonation cannot take place.

You aren't going to blow your motor at idle or light cruise by leaning it out. The question is, why are you having to take so much fuel out....I would look for mechanical reasons.

 

i was adjusting the cold start compensation....its way to rich on cold start...enough grey smoke to kill a parking lot of people (with a main cat)....just took it down too much its set perfect now