low ignition timing - The Unofficial BMW M5 Messageboard (m5board.com)

KAMIKADZE · 21st April 2005, 12:44

Hi
So I have E36 with S38B38 swap the car is runing well but I noticed that EGT goes way too high - 1460 F + ( 800degrees C ) that is on WOT and IF I drive at about 20% TPS with 4000rpm on second gear . I thing that this temperature is not normall for n/a BMW engine . The AFR is 12.5:1 , compression on each cylinder is perfect 15bar flat ( stock 14,5-15) all sensors are OK , valve clearence is exact that must be . So i think that there is something that cuts the ignition timing and raize the EGT . That thougth came to me when I did not hear detonation when use low octane fuel ( I am with Jim C chip ) , also I tried stock sparkplugs and Desno iridium IXU22 no difference ...
Please tell me what may be the problem that make the ECU to cut the timing ( there is no knock correction on S38B38 engine )

KAMIKADZE · 21st April 2005, 19:21

Here is whole story
So I have BMW E36 and put S38B38 engine inside.
I remove the airpump and tempomat
The engine is perfect 15bar compresion on each cyl ,
valve clearence is 0.30 , cams are on marks. I have
speed signal from 325i tacho . So the problems came
with Jim C chip the car runs with 12.5:1 AFR on wot
but the EGT goes up to 810degrees celzii. I thought
that there is problem and the ECU cuts the ignition
advance and raize the EGT. I put the stock chip then I
was amazed - on WOT the AFR is 10,5:1 and the car run
poor ... but in closed loop everything is fine. I know
that the ECU can enter in LIMP HOME mode or such but I
checked almost everything and did not find problem ...
Can you tell me what signals need ECU in WOT and what
can make it to go in limp home or such mode to cut
ignition advance .