I just got my B18B i rebuilt into my 1998 Ek Hatch. At first it surged to we replaced the coolant temperature sensor and the surge went away. Reved fine no surge at all. So i took it out for a test drive up my street. and at like 1000 to 2000 rpm is wants to surge while taking off so its kicking a little while taking off. but after that and get going its all good. anyone know what the problem could be. Thanks.

 

Check the throttle position sensor to see if it is broken or unplugged, that could cause it to surge. Was the motor rebuilt to stock specs or no? If not, was it properly tuned?

 

are your tps and map sensor plugs switched?

 

Well the tps was messed up on one of the throttle bodies to we switched throttle bodies with another and the surge at idle went away. so we messed with the throttle revving it and it surged so we changed the collant temp sensor. and that went away. so everything is good while sitting there. but while trying to drive it messes up a little. all the plugs are in the right place off the wiring diagram we have so it couldnt be that. The only thing thats different from stock specs is that it has GSR pistons instead of the ls pistons. Thats the only thing. Thanks for the help