wan2run

iTrader: (2)

OK, I've been chasing this problem for a while now and am at my wits end. At first it started out as an intermittent hesitation. I would be driving at cruising speed and I could feel it stumble every once in a while. I replaced the coil wire with an MSD wire (already have MSD plug wires), but it made no difference. It then progressed into the car cutting off while driving. After stalling, it would be hard to start, sometimes requiring me to wait a little while. After this I replaced the original coil with an MSD. The stalling became less frequent, but still occurred and the car would usually fire right up. It has now gotten to the point where it won''t start at all. I replaced the ignition control module yesterday, cleaned up the heatsink, and lubed both sides of it with fresh di-electric grease. It still won't start. I wanted to get opinions before I spend the cash on a new Optispark (40K miles on rebuilt motor and 2nd Optispark).

Any thoughts?

Engine Mods are -
LT4 Heads
LT4 Hotcam
LT4 Extreme Duty Timing Chain
GMPP 1.6 RR's
K&N FIPK
Thunder Racing MAF ends
BBK 52mm TB
Jet-Hot coated Hooker LT's, 4" Mufflex ORP, SLP "TOTL" Exhaust
NGK-TR55's, MSD 8.5 mm wires
OBD-I Conversion
Meziere Water Pump
March Underdrive Pullies

Quazz

iTrader: (1)

Try wiggling the ignition coil connector while cranking. Mine has the same issue. The black connector with the pink wire has an internal break. I can move it a certain way and the car will fire.

xxRONNIExx

Sounds like the same issue with my car. Did you ever find out the problem?

wan2run

iTrader: (2)

Turned out to be the opti. I performed the opti test from Shoebox's site - http://shbox.com/1/4th_gen_tech2.html#opti_test and was able to see that "B" on the ICM connector to ground was getting 0 VAC. Swapped in a new opti and it fired right up.