pre ignition problems

[gerjo]

this is a difficult one I hope you guys can help me with

recently I had an engine out job (don't ask) and because of that the pre-ignition timing had to be set all over again

the problem is that the dealer tried all settings from 28 degrees to 34, even 36, but the car just hasn't got the speed it did before

before it did 40-100 mph in third in some 7,5s
now I timed it at 8,8s, so it's over 15% down on power

I have a M Adam chip in my 500 and at that time I just plugged it in and it was very fast right away without adjusting the timing; problem is I/the dealer doesn't know at what timing it was then.
It has covered over 2.500 km since the repair.

any idea what can be wrong? engine is fully checked

thanks!

[shpub]

It needs a rolling road session by the sound of it. I think you were just lucky the first time round.

[gerjo]

quote:
It needs a rolling road session by the sound of it. I think you were just lucky the first time round.

yes, Mark is coming to Holland soon and will put it on the bench

you think this should do it?

[shpub]

Yes. Pinking is not just caused by timing. Fuel mixtures can cure or create it. Different compression as well. The golden rule is change anything, get a remap.

[gerjo]

quote:
Yes. Pinking is not just caused by timing. Fuel mixtures can cure or create it. Different compression as well. The golden rule is change anything, get a remap.

the problem is not pinking, it's that any setting we try doesn't give the power it had before, which is strange since the timing had to be somewhere between 28 and 36 degress and we've tried them all

[shpub]

Ok no pinking. It's just that you mentioned pre-ignition and that is a more sophisticated word for pinking. No problem.

If its less power then definitely get a Mark Adams session.

Steve

>> Edited by shpub on Tuesday 8th October 12:13

[gerjo]

o.k. will do

thanks as always Steve

regards
Gerjo