I need some help with a part throttle problem on a LT1-383 in a 95 Z28.To get you up to speed, I have a 6inch rod 383 with AFR190 street heads,CC306 cam, 58 mm holley tb, ported intake, pacesetter lt headers, 30lbs accell injectors, TCI street fighter converter ,msd digital 6 box,blaster2 coil,new opti and wires. 3.42 gears, 100 hp compucar wet shot. pcm for less tune (thanks Bryan), SS hood and SS cai, stock maf. The car idles great and runs great at wot , but, cruising between 2000 and 3000 rpm I hear a slight miss as if i had a plug fowling. Autoscan is showing this numbers;
Idle 925 rpm 2300 rpm
blk lrn 16 blk lrn 18
lbl 133/rbl 153 lbl 122/rbl 121
li 127-129/ri 125-127 li 123-130/ri 126-137
lip 4.1-4.3/ip 4.5-4.8 lip 3.6 / ip 3.6
maf 14 gr/s maf 32 gr/s
map 2.92-3.05
tps .60/ta 0%
bar psi 4.93 v
Am I feeling the cam below 3000 rpm or do I have other problems?
Corrections I've made: New intake gaskets ,same problem. New headers gaskets with ultra copper permatex, same problem. New opti ,wires,plugs (autolite 104 gapped at .035), and even swapped back to 6al box, same problem. New fuel filter and gauge reads 43psi on rail with no vac and 38 psi with vac.
Please help!
Lloyd

 

Sounds like cam surge, both your choice in cam and tuner make it highly probable.

 

Thanks for you help,
This surge is really noticable in lock up (below 70 mph). Can you make any sugestions.