My idle is surging from 500 to 1500 rpm.

This is on a JDM H22 with a USDM Intake manifold.

The only thing I changed was a USDM P72 to JDM P13.

Would using a JDM P13 with a USDM IM cause this problem?

All vacuum lines been checked and so has the IACV.

thanks.

 

fitv?

 

any check engine lights?
try bleeding coolant?
could be the cold start valve

Mike

 

Does it doing it all the time or just every now and then?