It's time for my GTA to pass smog in December/January so I have to take care of a timing issue that it has.

Now, I know my timing is off because when I hit WOT from a dead stop you can hear snapping noises from the tailpipes and my #6 cylinder is combusting in the header tube.

Anyway, my friend had a $350 timing gun that is precise to within 1/10th of a degree, so instead of regular timing guns that go from like 5-10 degrees of timing, this gun will set it to 8.2 if I want. I'ts totally sweet.

So, what is the exact, proper method for setting timing on a 92 TPI engine? Also, taking into consideration that my GTA also has an SLP PROM, what should I set my timing to? It's not my daily driver anymore so i'm interested mainly in passing smog well (which I know my car will anyway) and performance.

 

i'm not sure if the chip will effect what timing you need to use but stock you need 6° before TDC, if you don't have any internal engine mods then i'd start with the factory setting. with the car off, unplug the timing connector, it will be by the firewall in the engine harness, i think it's a brown/black wire. this will keep the computer from adding timing and screwing up your reading. start the car and hook up the timing light, point it at the timing tab and check what it's set at, assuming it's off, loosen the distributor hold down (9/16" wrench) and gradually turn the dizzy while checking the timing, when it's at 6 before tdc, tighten the hold down and check to make sure it's still at 6 before tdc. turn off the car and then plug the timing connector back in. go for test drive

 

Thanks, that's what I needed to know!

So even though the SLP chip advances my timing, I should still set my timing to factory 6 degrees with the SLP chip in the car and not the factory chip? Just wondering because my timing was fine until I installed the SLP and not it is not as good as it should be. I'll try the 6 degrees first and if that it still not good enough, I'll something different I guess. It's just that I have about 15 minutes with this timing gun on Saturday morning....

Oh BTW, there is no vacuum advance or anything I have to worry about unplugging on these cars jus the wire going to the computer that is the computers vacuum advance right?

 

come to think of it now, since you hear popping in the exhaust then your timing is too retarded. if you find that it's already at 6btdc when you check it then advance it a couple degrees until the popping stops and then add one ore two more degrees just to be safe. yeah, there's no vacuum advance with tpi

 

Thanks!