hi guys, my first post here. I got a 99-00 si (b16a2). So far, got cams and cam gears, and I/H/E, FPR and VAFC. Recently, my car have been idling weird. When engine is running, it stays at 650-800 rpm.. but 650 seems a little too low. FWhen I drive on the freeway, w/ steady throttle for example 60MPH , the car will choak sometimes, u feel like the car slow down a bit.. and but u step more gas, the car wont' go back up.. then in a sudden.. it went fine again. when this happen, i will know that my car will stall once I stop the car. unless I kept giving gas. According from car shops, I have already replaced brand new spark plugs (the old one were toasted already), and problem still occuring...but maybe just a little better. and the next day, I have replaced the ditributor rotor and cap (which I haven't replaced them since i bought the car. haha) the car so far seems fine.. but the idle still low.. once i stop the car, the rpm will drop all the way to maybe 600-700rpm.. then it will go back up to 750-1000rpm. I dont' have any serious mode. any ideas why? PLs help....sorry the post is kinda long.

 

first check all of your vacume lines on the intake manifold..make sure ur tps sensor or ur map sensor is not damaged....check ur vafc to make sure ur not running to rich...also try bumping up ur fuel pressure..

 

THANKS.. I will look into that.

 

I had similar issues. This topic comes up almost every day but since your a noob ill help ya

I fixed my issue due to the IAVC. Are you throwing any cel codes?

Try warming the car up, idle it(if you can). Locate the IACV(idle air control valve_ on the back of the intake manifold. Pull of the 2p connector harness. If your idle fluctuates even more or stalls, the IAVC is properly working. If the car does not do anything, its bad or clogged.

Remove it, and dissconnect the 2 coolant lines, spray out the vlave with carb cleaner and make sure the screen is spotless. Then reinstall it and reset the ecu. If this does not solve the problem, check vacume leaks, air pockets in coolant system can also cause unstable idle.

there is also a fast idle screw on top of the throttle body, try fudgeting with taht.
Bad idle could also be from bad headgasket, dropped sleeve, cracked sleeve, warped head, cracked valve guides, ect ect ect. check your compression if you think your car is slow.

whats your spark plug s gapped at?

 

thanks..seems like i got some serious help here.. i will give it a try.

update: just took my car out to grab something to eat. didnt' drive it hard but shift around 5k rpm.. going up hill.. then when i approached the street light. and slow down, the car died. (So embrassing on the street) anyways.. have to start it again and go ..

 

forgot to reply you.. i thought about the spark plugs earlier.. and i replaced the stock ones from ACURA. those ones cost like $20 a piece.