I have a 1998 civic hatch swapped with a b18c1 block with a b16 head. The engine would start up no problem but if the engine is cold/ start start. Still starts up good put it in gear, drive to the closest stop sign or light once the car comes to a complete stop the car stalls. Thai would happen till the car was hot. And it also surges between 1k all the way down to 100. Only at a stop I could be in neutral rolling to a stop and it won’t surge but once I stop it starts.

I noticed my tps was messed up so I changed it now the car doesn’t stall on start up but still surges. And man is it never racking driving it in traffic while it surges to a point where it almost stalls.

Things Ik about the motor is it used to be used for drag and has cams. Also had a nos set up before I removed it. Could it be timing?

 

Could it be a vacuum leak? Wouldn’t it be the other way around. As in I’d have a higher idle

 

Bump

 

Never mind learned the hard way again that it still does stall when cold. Any help?

 

Bump

 

Help?

 

Bump

 

Help me please?