Thread: Cylinder #1 misfire and random cylinder misfire

Ok so i've been trying to figure out why my spits and spudder under load (about half throttle or when i kick in the boost)! lol Ne way it's been almost 2 weeks after mods, hoping that the pcm will work itself out and relearn. The first time this happened it was a random cylinder misfire. so i check all the spark plug lead and plugs. The lead are with in spec of msd. so i cleared the code to see that worked. It didn't... still the same thing. i could still feel it and yet it wasn't triping any codes till a couple of days latter. When that code came up it was now a cylinder one misfire. There for i check the wires again and bought a new plug. I had also had to replace most of the vacuum lines as the broke when dismantling the engine. so i check to make sure that i had then in right. Next i took the injector of to see if it was dirty or what not. there was a lot of oil around the tops of all the injectors on the front bank...Hence UIM and LIM replacement. I reinstalled the injectors and i ran seafoam threw the lines. cleared the code and now i'm back to random cylinder misfire! I'm not ASE certified and i have done all the work myself. but i was very careful on making sure that i had installed the springs and rockers right and torque to spec. HELP PLEASE

i forgot to add that i haven't gotten it dyno ed or reprogramed the pcm yet cuz i wanted to work out all the bugs first! could reprograming the pcm to the mods help this?

probably some junk msd coils.

Well after talking with msd about my coil... these r the specs that they gave me.

uninstall coil pack
Test 1: test the 2 pins on the bottom. they should have a .35 ohm on cold engine.
Mine were .6 ohms on all three
Test 2: test one pin and one tower. that should be 7,800 ohms or 7.8k ohms
I got zero 0
Test 3: was to reinstall coils and leave the middle bolt out inbetween the towers. and see how it runs
When i did this the idle was very rough so now they want me to send them in for testing! i put my stock coils on... my random misfire is still there but not as bad and still only does it under load when supercharger boosting! ne ideas? my thought is also that there is something wrong with injectors! but after reading some stickys i guess i need 42.5# injectors with the mods that i have!

Get rid of the friggin crap MSD coils. They are NFG.

look @ my signature!

you're probably seeing some kr under load with that 3.1 pulley, have you ever scanned for kr?

i was just reading the sticky on KR. my brother has a scanner but not sure if it reads KR. the other thing is i'm going to check the plugs to see if maybe i have a bad fuel injector.