I need help I have 91 l98 TPI. I am having trouble with the timing I set the timing and right now it's between 6 and 8 DBTDC and it idles fine but when I drive it around I have lost all power so jacked it up put it in drive got the timing light out and checked it with it in drive from 1 to 4 thousand rpm and it drops around 2 to 4 degrees BTDC. I'm not shure whats going on, no advance I guess. Is there any way to adjust this? I'm not to familure with the process. o yea I do have the est wire pluged in. If someone could point me in the right direction it would be a great help. THANKS!!!

 

You must disconnect the spark control connector on the firewall.
If you don't you will retard your initial timing so far (25-30*) to get it to idle and run, it won't be able to advance more than a few degrees. That's why your not getting more than a few.
End result; no power, and really bad gas milege! There should be a MFG sticker on the underside of the hood that will give you the procedure for setting the ig timing.
The connector is in a black wiring harness that runs across the firewall in front of the passenger side. 2 wires in, 2 wires out.
I can't remember what color they are but it's the only connector in that location so it's not hard to find OK?
Good luck!