92crimsonRS

got a random miss going on and cant quite track it down.

new

tps
iac
clean maf
egr
iat
cts

covered all the basics. new cap rotor. plugs are clean. show good burn. wires are iffy but ohm test fine. new knock sensor.
have msd box and coil. tried stock gm stuff still stumbles.
used a timing light and can see that the coil hiccups when it stumbles.

what controls when the coil fires? i changed out the ICM with a known good one from my truck and it runs the same. could it be the pickup coil?

89 TPI 168 miles on motor.
all wires checked all grounds clean.

i am running underdrive pulleys but not sure what idle voltage is. will check tonight. as well with win aldl and then post logs later this week.

92crimsonRS

also if i unplug the est connector it runs worse. shakes violently and almost dies every 5 secs.

sorrys70

my guess would be the injectors, my buddys tpi engine had similar problems we replaced the injectors on it and it was like night and day. good luck

92crimsonRS

new injectors.

found my issue. bent pushrod. finally started ticking. looks like i need self aligning rockers as one walked off an chewed a valve up.
also had a bunch of oil in no.4 cyl. not sure how i got oil in there but it has not fired at all cause the cylinder is clean as a whistle and the plug was fouled.

so now the head is at the machine shop to do all seals and replace the two valves.

92crimsonRS

double post

sorrys70

Reving pretty high huh lol

92crimsonRS

no. i didnt think to look at what rockers i was running. i need self aligning rockers and i havent been running them. i got a bent rod out of the box i think as i got the set right before i rebuilt the motor and it was loud then too. im gonna replace the bent ones and use stock rocker arms.