I have an 88 s10 and I put a 350 TPI with Speed Density in it. When i start it pops and idles very rough and high so i though that the timing was off so i disconnect the EST and set the timing at 6*. When i am setting the timing with the EST disconnect it runs good there’s no pops out the exhaust and it is very smooth but when I plug the EST back in the timing goes way advances and it starts popping and being rough again. I’ve tried setting the timing many different times. Maybe I just doing something wrong this is the first time I’ve worked with a TPI.

Any help would be great

Thanks

 

Make sure that the TDC mark on the damper outer ring is in fact top dead center. The torsional damper rings sometimes slip, giving a false TDC indication.