Here's the low down. I dropped a low mile 94 z lt1 into my 95 Impala SS. Before I dropped it in I put in the hot cam kit.
Well it runs great usually from idle to 3/4 throttle. If I try to give it hell it pops out of the exhaust and falls on its face. If I continue at full throttle it will usually stop missing/popping and run fine, until the next time I try to do it. Every once and a while it will do the popping/ miss right when I take off in first. The car is throwing no codes at all. If I drive it like an old lady I can't tell anything is wrong at all. It also runs better up top when I gradually give it more gas.
I was thinking maybe I didn't get the rocker adjustment right. Maybe coil or opti spark?
Anyone have any ideas for me to look into? My autometer fuel pressure gage also looks good @ around 42 psi.


Thanks
Brandon

 

What did you replace when you did the swap. How many miles on the old opti?

 

I replaced the waterpump, plugs, wires, head gaskets. I should have replaced the opti but MY wife was on my case. the motor I dropped in had 39,000 miles but sat for 8 years.
brandon