Is the dtc p0506 related to my new bbk 58mm tb? I have just started the motor, brand new, just trying to work out the bugs. Alldata said it could also be a vaccuum leak, my best guess for that would be the intake manifold but I have not checked it yet. Also, it idles a little high, 1000 rpm, and there are no cats on it yet, maybe some info someone would need to know.

 

P0506 = Idle control system - low engine speed. That would indicate its idling lower than spec. Fail criterion is the engine idling 88rpm lower than the target idle speed. Are you sure you didn't get P0507 which would indicate higher than spec idle?
diagnostic routine, that is run after the initial problem (low idle) is detected.

When you install a new throttle body, its generally best to SLOWLY adjust the idle speed, while watching the IAC counts on a scanner. Tweek the adjuster screw until the engine is idling right on spec, AND the IAC counts are in the range of 20-40 (higher with a more agressive cam). When you have both the idle speed and the IAC counts correct, then check the TPS voltage to make sure it is in the range of 0.20-0.90V. Some people prefer to set it at 0.50-0.67V, and you may have to slot the throttle position sensor bolt holes to adjust it.

Its also possible the TB has casting flash in the idle air passage, or that you screwed up the transfer of the bottom plate, getting a poor seal, blocking the passages or damaged the IAC valve. Are you sure you hooked everything back up, including the IAC valve and the MAF sensor?

 

Im sorry for posting the same question twice, thought the title needed to be more catchy to get some responses. I havent tried adjusting the idle yet but im on my way to work and ill try that when i get there. Thanks for your help.