Lt1 random misfire

 

Ijust put a new engine in my 96 Z28 very few mods the engine is .030 over,new accel opti-spark dist ,BBk throttle body,accel injectors ,aeromotive adjustable fuel pressure regulator ,lt4 knock module and jet mass air flow sensor it runs good butI can detect a random misfire with my snap-on scanner....I've ranall kinds of sensor tests but I can't find anything axcept for the Map sensor stayed at -.55 v on my scanner but when I did the test manually the voltage was at 4.7 v....it's been 2 days now of this mind racking crap can somebody any body please help me????[&:][&:][&:] like I said the engine runs good under load but enginemisses when not under load...I was thinking ECM....what do you think?..

 

i had the same deal with mine, ended up being a plug wire. all i can say is check the plugs and wires, and even the opti. i know you said its brand new but i have seen distributers and coilpacks both be bad right out of the box. hope this helps.