OK- so you can't set the timing on a tbi chevy like normal
without the chevy computer screwing it up I found.
On the 88?-95 chevys- you must: ( I read this somewhere)
warm up the engine, Disconnect the tan w black wire coming from the distributor to the
computer (this in turn confuses the computer until it gets re connected)
*Note: on my 1995 wiring harness- unless I took it out before installing because I didn't know what
it was for- there was no disconnect plug on the tan/black wire. I had to put one inline.*
With your timing light hooked to the battery posts and the pickup hooked to the number 1
cylinder wire, AND the bolt clamping the distributor down loosened lightly......
start the engine making sure to avoid the fan,belts and anything else dangerous-
set the timing line on balancer to 0. The engine will run poorly during this.
(one site stated worn engines can be set 2 to 4 to compensate for slop)
Stop the engine. Tighten the distributor bolt. Make a mark from the distributor to the clamp
marking where 0 was. Plug in the tan/black wire back together ( slap some dilectric grease
in there) and be amazed how much sputtering disappeared the next turn of the key.
heres the video i watched until 2:42 then blah blah blah.