ive searched and cant find lets say idiot instructions for advacing the timing on my 92 305 tbi. well over winter im rebuilding my 305 all new gaskets and new timing chain since mine is streching out i know when i go to advance it i have to disconect the advance timing wire by the heater ok but how about mechanicaly do i go about advancing it?ive read something about turning the distributor and to do this you must loosen the hold down? im kind of lost

 

da_jester

On your engine, the computer controsl both types of timing, vacuum and mechnical.

In a non-computer controlled distributor there were weights and springs to adjust the mechanical advance and a vacuum connection to adjust vacuum advance. For your HEI this is all done by the ECM.

All you need to do is set the "base" timing, this is where the computer will adjust from. For example, if you set the base timing at 0 degrees and the computer is programmed to add 10 degrees at 1000 rpm you'll end up with 10 degrees at 1000 rpm. But if you set the base timing to 5 degrees, you'll end up with 15 degrees at 1000rpm (the computer still adds ten!)

It is important you set the base timing correctly. It should say on a sticker in your engine compartment. Like you know, you'll need to diconnect the EIC wire so the comptuer isn't controlling anything. Then take a timig light and adjust your base timing to factory spec. Shut off the car and re-connect the EIC wire, the computer should take over from there.

Be sure you MAP sensor and Knock sensor are good as these are the main sensors the computer uses to adjust timing.

 

ok well there is no sticker guy who painted the car did realy bad masive over spray under the hood can read ne stickers so now what?

 

My 1991 RS 305 TBI has this label: So, set it at 0 degrees...

 

ok well how do i find out what the electric advance sets it at unplug it set it to 0 then plug back in and see where it sets it?