misses all rpms, i'm lost

[ryans]

hey guys
I got a 98 GTP well one of the pistons bit it and all valves were burnt. so I just rebuilt the motor installed a comp cam just above stock specs, and a double roller timing chain new pistons and bearing. it already had headers, no cat. 3.4 pulley thrasher intake,Tbody spacer.
after a run and multiple misfire code came up (pulled good though 1st gear). I got a custom pcm from intense, also installed new balance at same time because it rattled a bit. after i started it it seems to act like it is runnin on 3 cylinders. I know i need a case learn but was hopeing it would run good enough that it would make it some were to do that. but it wont barley back out of garage. all sensors are new. would a case learn make that big of a diff. also on my scan tool ( no code) I'm getting 21 deg at idle and goes right to 31.5 deg at any amount of throttle. HELP has any one been through this.also i'm using stock plugs, i always used a colder plug on my bbc motors runnin high comp. what do you guys use on similar setups,

thanks

 

[dsmuts]

Doesn't sound like plugs are your problem but try some al104

 

[tylerbinski]

Did you disturb the crank position sensor?

cracked porcelain, bent electrodes ?

Have u pulled plugs ? Any clues?

 

[Explicit_Spade]

What are the cam specs? A cam with big enough lope can set off the P0300 (Random/ Multiple Misfire)

You could need to do a CASE learn.

 

[darkhorizon]

you dont need a case learn unless the PCM asks for one... Its rare that you would need to do it honestly.

 

[MoarkatsINmuhtrailer]

Even a smaller cam like the vs will set the multiple misfire code