alright so a few days ago i finished putting in a b18c1 GSR swap in my car. Right away it had some bucking problems that i thought would be solved when i fixed the tps (throttle positioning sensor). Today i got the tps problems fixed but it still bucks. What im thinking it might be is the idle air control valve.
Does anyone have any ideas on what else it might be? The car runs great all except for the bucking and idling issues.

 

when is it bucking?

 

What CEL codes are currently being thrown? Definitely fix the IACV as idling and bucking problems may have the same root cause.

 

Double check your cam and spark timing. The test jumper must be in place to set the ECU to timing check mode when adjusting the spark timing. Probe in cylinder 1 to confirm that the TDC mark on the pulley is really TDC (if someone put it together without the key, the mark won't be right.)

You could also be misfiring due to a bad plug or wire or a crack in the distributor cap. Are all those parts new?

I don't think an IACV problem will affect driving once you step on the gas. The throttle plate lets in a lot more air than the IACV ever could.

 

its bucking anytime im trying to keep it at a steady speed. i found that the IACV on the engine is a two pin plug and the the plug on the harness is a three pin. I think thats what might be causing the problems.
the distributor and all that is new.

 

definitely

use this info. scroll about halfway down it and you'll see the 3 pin to 2 pin fix.
the pins in step 1 refer to OBD2a (96-98) wiring.

 

thanks for the info trustdestruction. Turns out that it was a two pin anyways, my bad.
I still think its a faulty IACV. Some of the symtoms include bucking when i try to keep a consistant speed and from what i've heard the iacv is what causes that problem. Do you think thats what it is or could it be something else?

 

Pull the CEL codes and post them. Have you looked into mk378's suggestions?

 

yes i have looked into mk378's suggestions. I had the timing and all checked and its perfect. The engine isn't throwing back any CEL codes.
Its possible that the iacv is just dirty or in need of a cleaning.

 

Was the new TPS properly calibrated?