PorKen

Yes. Note the (4) unwired pins in the diagnostic plug can be used - they just need to have the tarnish removed before soldering.

'88-up concerns the stock code/EPROM that is installed in the EZ. There is a big jump in the amount of code from '87.
It was originally written to fit tightly on a 8K chip. By '88 it was ported to a 16K chip for additional diagnostic code.



Almost ready in a coming update is an additional feature using the Sport Mode indicator light (if you have made one). If you hold the accelerator down slightly while cranking the LH will clear it's learned memory and go into 'CO mode' which will show the state of the O2 sensor, rich/lean (similar to the S3 output). It will stay in this mode until a restart, or rpms go over 2000.

Currently, on all versions of the S4.S300s chip, holding the accelerator down when the key is turned to 'on' will reset Octane Adaption. (If you fill up with higher octane, for example.) The knock light will come on to show that it is cleared. This happens automatically if coolant temps drop down near the first white block.

littleball_s4

Hi,

Which pin of the 87 diagnostic connector is knock?

I have a Mhz logger with pulse count function and would like to try and see.

Tnx,

PorKen

Position #4 is knock '87-'88. (There are small numbers embossed on the plug.)

https://rennlist.com/forums/10437024-post2.html

littleball_s4

Thx porken.

Will report back about my findings. As soon as I replace the ISV and cure the new intermittent overheating problem.

It's been a busy shakedown after engine rebuild (so far: heater hoses burst, cooler hose failure after rubbing agaist belt, shifter cup popped, beam lights failure, wrong code plug, and now intermittent overheating; all in 1000kms and 2 months).