E30...timing retard

Does anybody know how to retard timing for an 85' 325e? Is this even possible?

Thanx

why would you want to do this,is there a problem with the motor?data I have show 85to 93 325 e30 eng code 25 6e 1/2 not adjustable.is this your model?

I can't seem to pass smog. Hi Nox. I was told that retarding the timing should bring the Nox down. I guess it is not adjustable.....85 325e. Thanx anyway....

your problem is likely a lean condition which also raises combustion temps. to create high NOx, as might an engine running to hot. check all the engine air hoses for leaks then have a shop set the CO % as close to the rich spec's as possible, and no, your timing is not adjustable.