ok, the motor is a OBD1 JDM b16a. The motor ran fine before, now its running like **** and I have a CEL, that i tried to check using a scan tool, and using the paper clip method... It doesnt work, i think the diagnostic ports are not hooked up, seeing how it is a motor swap.

On to the problem....

When i start the car, the CEL comes on like 3 seconds after i start it, if i shut the car off, the CEL goes away, its not present when i put the key in the "on" position. When i barely press the gas and slowly bring the rpm's up to 1500 it just stops there and hit "a rev limiter" so to speak. It keeps bouncing like its hitting the rev limiter until i press the gas harder, then the rpms rise... Another problem ive noticed is when i am driving and slowly let off the gas to keep at a steady speed, the car WILL NOT let me, it either decelerates or accelerates, there is no constent speed. Its a rough transfer from accelerate to decelerate also, its very jumpy.

Today while trying to fix the problem, i unplugged the vac line running from the FPR to the intake mani, when i started the car, the idle was roaming from like 1k-2k rpms, but there was NO CEL and the idle wasnt stopping at 1500 like a rev limiter. I do not want to drive the car w/o the FPR vac line, pretty much because i dont know what will happen.

Ive also took the fpr vac line off and hooked up a vac gauge and the vac seems fine, stays right at 19-20 at idle... would a bad FPR cause the CEL?

Any help would be great,
thanks in advance,
mike