So the car is a 92 z28 originally 305 but has a 350 in it with the 193 heads (caprice) TPI etc. Should the timing be 6* or should it be the same as the Caprice? right now i have it at 6*, but on a cold motor it backfires when shifting out of first/second. When it warms up it is ok, but i have a small misfire at idle... could this be caused by the timing being at 6*?

Thanks

 

Did you do anything different with the computer? MAP or speed density systems don't take well to displacement increases without retuning.

 

I tuned the computer with the following:
-Changed the volume per cylinder
-changed the injector flow rate (22 lbs Bosch design III's)
-changed all VE tables to that of the AUJP's... (didn't know if that was the right thing to do...)

 

The TPI computer wants the timing at 6 degrees. That's what's important.

You'll need to do a datalog and figure out if the engine is too rich or too lean when its cold, and adjust the tables accordingly.

 

Thanks kevin.

I think i'll check out each header pipe with an infrared temp gun...

In your guys opinions, is changing the VE tables to the AUJP ones a decent move? (different heads than the L98...) the car doesnt backfire when cold anymore.... but it will idle pretty high when im coming to a stoplight and stay at around 1200 until i come to a complete stop...