Would a bad thermostat in my b16a cause-

Rough idling- cold start, idling at 2,000 sitting for 10 minutes then all of a sudden drops down to 1,200 rpm's

Hesitation when accerating-

Slow throttle response- as sitting in idling taping the gas, it almost stalls out then rpm's kick up.

if the thermostat isn't the problem, is there any other suggestions you guys can
think of? thanks

 

What makes you think it's the thermostat? any problems in that area??

What year is your car?

How much mileage?

fs

 

If the engine runs well when the engine is cold, then maybe it could be due to a stuck open thermostat. Or some sensor is sending bogus information when in closed loop after warm up.

Your warm idle is still too high at 1200rpm.

 

Sounds like IAC to me. Have you changed your fuel filter lately??

hth

 

i would start by checking for vacuum leaks

 

Maybe O2 sensor? Just a guess.