Whenever I cold start my car in the morning the car takes a couple more cranks than normal (compared to my old sohc) to turn over. After it turns over the motor jumps to 1500rpm then drops to around 500rpm for a second then rises back to 1500 rpm and stays there. I checked the main relay (it clicks properly), fuel pump (makes proper noise, no bogging) and I don't throw any codes. If i start the motor when it's warm everything is fine. Any ideas? TIA

 

my b16 i have to crank for like 15 seconds...i usually have to crank it for like 5 seconds then stop...then crank it again and after a couple more seconds it will start up fine but yeah my rpm's jump allllll over the place then after its kinda warm it idles around 800-1000 but if i turn on my lights or anything the idle will drop to like 600...i duno what it can be i guess its not a real big deal as long as it dont stall

 

my b16 is the same way, takes a minute to start..

 

I know that its not a B16 but my LS-Vtec has a B16 head on it and does the same ****. Ill start the car and until the thing is warm it struggles staying running if I hit the gas slowly. After about 20 or 30 seconds of running its fine. I dont know what the hell it is either. I have tried a new distributor cap and rotor, new o2 sensor (I am only running the main o2 at the moment on my pr3 ecu, Soon to be installing the second one and hoping it will fix this prob). I am lost for leads as well.

 

I got the exact same thing going on with my B16A. I thought something was horribly wrong when I started it up one day, but then within a short time it runs fine.

 

i dunno about a b16, my my z6 idle's really low when its cold

coolant temp sensor is fucked up. car thinks its warm all the time

check it, and make sure it works. mine just started getting worse, and it threw a code for it. i think its under the IM