1991 civic Si 1.6L. When hooked to a smog tester it shows ignition timing is at zero. When I jumper the service port it does nothing. Doesn't override the brain.

 

I have never been to a smog test where timing is measured. How are they doing that? When you put a timing light on it, without the jumper shorted, what does it measure? Have you verified your mechanical timing? Is the distributor connected properly? Has there been engine work?

 

Checked mechanical timing, it's correct . Car runs good. California smog tests always list ignition timing. It just worries me that I can't override the brain to set the timing myself. I don't think the timing is actually at zero. I don't think it would run good if it was. I hate assuming that it's OK. Is there another way to engage the timing mode other than the service port ?

 

Still trying to understand. With your 1991 Civic, there is no OBD port. The only way to check electronic timing is to put a timing light on the engine. Are they doing that? If they are 'listing' the timing as '0' on the report, that's because there is no OBD. If your car truly had 0 degrees timing (and no advance), you would certainly know it. You would have very little power, especially in upper RPMs.

 

The only time they should even worry about the timing during smog is:
1) you have a check engine light, then they will start digging to find out what is throwing the code
2) your car is idling or running rough, such as sputtering or idling rough
3) your emissions are not within levels, in regards to this timing would be either the last thing or the first thing they check, depending on the levels.

 

^ They check timing in Cali smog, it must e within spec or you will fail.