91civicse

k ...i have a 91 civic se 1.5l and recently it has been having trouble idling like it wont die but when i first turn the car on the rpms will go up to about 1500 then down to 500, up then down and so on, until i give it a couple of quick shots of gas and then it will run fine, i have recently replaced plugs, wires, cap, rotor, fuel filter, oh and also the altenator (approx. 6months ago). could this be a fuel pump issue?? the pump seems to be working because when i turn the key forward without starting the car i can hear it for like 5sec then it stops so i know its getting up to pressure..also occasionaly when im at a light the rpms drop to the point that im about to stall but then jumps back up to normal,...now i do have a short ram intake and "performance" muffler i dont know if these are to blame for this issue , i dont think so because it has run fine while these were on , anywayz sorry for the long post i just really want to get this straightened out before it becomes a real issue. so yeah if any1 thinks they know what the issue is and how i could fix it. i would greatly appreciate your input

Kai

First off, check the coolant level both in the radiator and the overflow bottle. Air bubbles in the cooling system can cause a bouncing cold idle.

MTEng

You may also want to check/clean the idle air bypass / idle air control valve in the throttle body. Use intake cleaner (some have lubricant for the IAC valve).

91civicse

i checked the coolent levels and they look fine but i did have some bubbles in the rad, aside from topping off, i've never flushed/filled a rad so how would i get rid of the bubbles?

and i havent had time to check the iacv, but i will, i just need to pic up some more cleaner....also i seem to be running rich im guessing this could also be adding to the problem, but again dont know how to fix it