what are the symptoms and possible dangers of running timing either too advanced or too retarded?

I had the timing all the way advanced for some reason and my car was misfiring sometimes and occasionally hunting idle. Because of emissions, I had to retard timing to lower nox. Since I couldn't set timing with light(crank pulley dirty and only 20 min till closing) I set timing to as far retard as possible. Now my car runs great! It's a little underpowered but no more misfire or hunting idle. It's never run this good! I plan on cleaning the crank pulley to properly set the timing but in the mean time I'll leave it as is. I just want to know if I caused or will cause damage.

 

You need to properly time your engine with a light. There's no sense in running with extreme timing settings just because. If you have hunting idle, or a failed emissions test then you have other problems you need to address.

 

The timing will be fixed once I have time to get down in there and clean the pulley.

Hunting idle is no longer an issue since I retarded timing. I passed emissions like that as well. If I remember correctly NOX was 2.48g/mi out of 2.5g/mi allowable. Everything else was half allowable. I think I'm going to have to replace the cat next time but I was also thinking of just getting a vintage plate. I think with one of those I don't need to take to emissions any more.

 

It sounds like you don't want to fix your car.

Hunting idle is fixed from maxing out your timing and it doesn't matter that the car is running poorly because you can just get vintage plates. Makes sense. Good luck with all that.

 

Hehe... I appreciate your help kp!

 

More than likely you did not cause damage, but timing left to either extreme can cause damage over time. Too retarded and you'll be washing out your cylinders, to advanced and you could do that along with burning a hole in your pistons. Best to get your timing set properly sooner rather than later.

 

Thanks UndergroundTrev. The reason why I was asking this question is because I wanted to find out why the timing would it to stop the idle issues.

I've adjusted timing to within spec.. So far it still runs great and I've got more power.

 

The ECU controls idle first with ignition timing adjustments, then by the IACV. Timing changes effect idle instantaneously whileas the IACV alone is much too slow to catch the engine from stalling.

Advancing the timing raises engine idle speed. The ECU compensates by pulling the timing back as much as allowed, probably a couple degrees at most, then by nearly shutting the IACV. Now instead of being in the middle range of the IACV and allowed timing adjustment, it's maxed out in one direction. You'll experience high idle, hunting idle, frequent stalling, high NOx, decreased mileage and power, messed up spark plugs, messed up O2 sensors, shorter engine life- all around bad ****. Fully retarded is also very damaging as mentioned. Ignition timing is the most important setting second only to cam timing.

If you want to tune base ignition timing, you'd want to stay within spec. +/- 2 degrees of 16 or 12 degrees in most cases. You might do this to pass smog or decrease pinging. If you want to tune timing for power, you'd need a dyno and a reprogrammable ECU.