i just fisinshed my b16 swap into my 91 si and i started it up last night and it idles at 3500 to 4000 rpm. the motor did the same thing when i removed it from the car that it came out of. when i started to take the motor out of the other car i discovered that a vaccum line was not on the throttle body and assumed that was the problem. however it was not. i checked everything over a million and a half times and even switched the tps with 3 others and didnt solve it. it also runs super rich which leads me to believe it is a vaccum leak and i really dont want to rip the intake manifold off and put a new gasket in if i dont have to. i dont think it is bad because the motor was just rebuilt and has about 5000 miles on it. any suggestions would be much apprecitaed.

 

r u sure everything is hooked up? make sure that u burned the right map if ur useing uber or crome

 

it ran fine for about a year and then all of a sudden right before i switched the motor into the other car it strated running like garbage. i know its not the ecu because i switched mine with a bone stock pw0 and it didnt change a thing so it has to be something with the motor

 

it could be vacum leak, it could be map, it could be a lot of things, good luck

 

hi....hi have same probleme like you......now it s good ....the probleme is THE FAST IDLE THERMO(FIT)VALVE is mounted on the under side of the throttle body....and retained by three bolt......sorry for my english am french .... mart

 

I had a very similar idle problem with my b16. Things I was told to check are: Throttle cable not too tight, try pullin back on the gas peddle. Idle Air Control Valve (IACV) it's located on the back of the intake manifold, it can be taken off and cleaned or replaced. Fast Idle Thermo Valve (FITV) this is located on the bottom of the throttle body, it can be taken off and adjusted by removing the cover and screwing in the large white wax screw or it can be replaced. You can also check for air in your coolant as this sometimes causes high idle. Hope it helps

 

u could try closing the screw on the throttle body with a flat head doubt it'll work but worth a try