Thunderlips

Heres an interesting one im going to throw to the lions.
Whilst my car was being mapped two weeks ago huge amounts of det were indicated on the laptop even though my knocklink indicated very little and an additional knocklink wired up as a backup showed bugger all.The man mapping my car is very good and said that the amount of det indicated by the cars own sensor via the laptop would have lead to us at least hearing or noticing something, we carried on and mapped the car, but didnt kick the backside out of the boost just incase. The car was run on optimax with NF octane booster, I always use it.The conclusion we drew was that the cars own knock sensor was miss reading and needed replaced.There is no damaged valves or anything like that which would generate "knock" and be picked up. My question is has anyone else come across this before?the car is a 95 STI RA.

Peanuts

iTrader: (15)

unfortunately(?) you have quite a rare car, but when my MY99 MAF was under suspicion I bororowed a mates to check and found my own was ok.
do you know any other RA owners?
have you tried this breakers yard..?, I got my washer pump delivered this morning and they really are very good

Andy

Peanuts

iTrader: (15)

oh, could it be that a previous owner wasnt as carefull as you (ie no booster) and that an ECU reset will get the car to run on the better grade of fuel/booster?

Thunderlips

Thanks for your interest but I have just installed a Possumlink ECU and had it mapped, thats how I can tap into the cars own knock sensor via a laptop She has been mapped to perfection, I am convinced the sensor is buggered I just want to know if anyone else has seen this before.I have the sensor switched off but have my own knocklink and sensor wired and working as you would expect. They indicate nothing out of the norm.

dnb

Can't you swap the sensors over? IIRC the knocklink sensor is very similar to the OE knock sensor.

Should tell you something about what's going on.

Thunderlips

Yup, the sensor is a bugger to get to but that is my next course of action Ill let you know how I get on.

Bob Rawle

The output from the knock sensor as displayed by a Link ecu is just that, the output, it does not denote knock in itself, you have to determine that yourself (or your mapper should for you) so if you are in doubt then go back to him and get it clarified.

High numbers DO NOT necessary mean knock, your engine could just be "noisy". The sensor could be going "microphonic" but in practice thats unlikely.

Correlation between det and the numbers is vital in order to set the proper retard trip level.

cheers

bob