Hi, I have a 92 Accord EX which at idle, has very low rpms. When I bought the car, it revved at 500 rpm in idle. I discussed this with some mechanics and they told me not to touch the rpm if the engine wasn't stalling.
Nowadays, I have notice that the car idles at around 300-400 rpm which to me is very low as the normal is supposed to be around 800-900 rpm. The car is starting to get the inital shakes for stalling but up till now, it hasn't. Any idea, what the problem could be? what I can do to correct this?

Thanks

 

check the throttle cable, might be a little loose, try to tighten it up, mine does that sometimes, and i just pull on mines, and it's fixed.

 

Don't adjust throttle cable. What you need to do is adjust your base idle. To do this, start engine and allow to come up to operating temp. Next, disconnect IACV, this is located on intake manifold between manifold and cylinder head. If you disconnect IACV and engine dies, base idle too low. Now, there is a screw on front of throttle body that make have some gray tamper proof sealer on it. Once sealer is removed enough to get a flat blade screwdriver on it, back screw out about a turn and a half and try restarting engine and see if it will continue running. If not, back out screw another turn and keep trying this until engine runs on its own.

Now, with engine idleing at operating temp and IACV still disconnected, using an inductive tachometer, or timing light with built in tach (factory dash tach not very accurate) turn idle screw on throttle body out to raise idle or in to lower idle. Target idle with IACV disconnected is 500-550 rpm. Once target idle is achieved, turn off engine, reconnected IACV and clear codes by removing 7.5 amp backup fuse from under hood fuse box for at least 10 seconds. restart engine and allow idle to stabilize for roughly 2 minutes and then recheck idle with tach to ensure base idle is approx. 700-770 rpm. this is you target base idle and should take care of your problem.

Hope this helps