Is setting/advancing the timing on a 1989 Iroc,TBI,5.0 the same procedure as setting it on a 1992 Firebird ,TBI,5.0?

 

Yep - disconnect the EST wire, start car, adjust timing to spec, shut off car, reconnect EST wire.

 

One more question. Whats the stock timing setting for the "92" and what kind of HP/seat of the pants difference can I expect.

 

hmmm seems like ive asked this before. . . .

and how much is to much for a tbi motor 305 .. .

 

I want to think that factory specs on the TBI motor was timing set to 0. Some folks gain a bit by advancing the timing to about 4*BTDC if I remember right. Been a long time since I was TBI, and my brain is weak

Doubt you'd notice a great deal difference - maybe just enough to tell a difference, but it won't shave much if any time off a 1/4 mile run.

 

I think its old age but what is the EST wire?

 

Electronic Spark Timing - it's the wire that connects from distributor to Electronic Spark Control Module that allows the module to advance/retard the timing based on current conditions. You have to disconnect it before trying to set base timing - with it connected the module is constantly changing the timing and you can't get a fix on it. It's the tan wire with a connector that exits the wire loom close to the driver strut tower and re-enters that same loom.

 

This is a photo I found on the Internet ( I don't think its a third gen. but is the same wire and in the same location as my "89".)Mine is next to the AC blower motor on the firewall and passenger side.I guess they may have moved the location in a 1992 acording to camaronewbie

 

Mine is an 87 in same spot. Let me ask, MY 87 IROC idles smooth put it in gear and the car shakes, drive it it sounds like its missing.. What are the chances the timing is not advancing when i put it in gear? If its not advancing would this be a sign of rough running in gear?