Hi, can someone run through a list of steps for checking timing on an LO3? I searched and couldn't find a tech article or another post about it. My car idles funny and is pinging. I have a old-school check engine light and my friend claimed my timing was 14 degrees advanced but I dont see how thats possible. Also, what is this ESC or EST that i have to remove? Electronic Spark Timing? Thanks for your time,
Adam

 

After youve made sure the motor is up to temp and at the proper idle speed (should be to begin with since the computer controls the idle) you need to disconnect that connector you mentioned in order to bypass teh ecm. Obove the heater box there is a single wire sealed connector in the loom. Pull it out and disconnect it. Rotate the distributer to get the desired base time and retighten it. Reconnect the connector and clear any stored codes and thats it. The label that has the specs for the timing, spark plug gap, etc. is on the underside of the hood.

 

For what it is worth, you should be about 20* advanced, if the computer was plugged in when you timed it.

 

Check out the "New to TBI" thread at the top. It has a timing section that will help you do it. It's real easy.

 

Setting your timing
Timing tech article

Here are the two links that Bron mentioned. Both can be found in the new to TBI thread as mentioned.

 

Ok, sounds good, I'll try it this weekend.

 

I have one more question. That wire that needs to be disconnected on my car looks brown/black. Upon disconnecting it, the inside part is round. Is this the correct one? It did light up an engine code and if that was it, the timing was advanced 4 degrees. Let me know, thanks,
Adam

 

Nevermind, the other tech articles describes the wire better. I guess the next step is to take it back to 0 since im using 87.

 

Here is the EST wire.

 

Yup, same one on my car, thanks for clarifying.

 

Well the car was set at 4 degrees retarded. That would explain the crappy idle. I advanced it 2-3 degrees ant it idles great. However, I hear what sounds like pinging but its very faint and only present on partial throttle and no WOT oe idle. I've had thing "pinging" for a long time even before the timing fix. Since then I have had GM top engine cleaner and a tbi cleaning performed. Any ideas?

 

What is your new timing setting? You could have ping if you went to far for the octane you are running. Run something higher and see if it goes away. If you still here it with only 0* base then carbon deposits could be the culprit.

 

I checked it after the tightening and its at around 0-1 degrees advanced. I have always thought that pinging occurs under load or at WOT. This occurs at partial throttle and I don't hear it after 40mph. I've had a GM top engine cleaning done and I try to maintain the car as best I can. This is either not pinging at all, or its pinging and there is a crapload of carbon buildup. I doubt its either since the motor has 70k. This "pinging" occured even at the 4 degree retarded timing so maybe its something else?

 

I have a 88 camaro with the L03. The owners manual says to use premium. If I don't it pings. Your engine might require a higher octane.