I'm having a problem with my idle. It tends to stall out, even after I drive for a while (up to 1/2 hour or more), if my foot is on the clutch or I put the car in neutral.

If I pull out the choke, the idle will increase for a while, then drop down to stalling speeds again. If it doesn't actually stall, the idle will surge back up to rpms expected given how far the choke is out.

It'll also hesitate when I step on the gas. When this happens, I know not to put the car in neutral or step on the clutch for a 'long' period of time; if I do, it'll stall.

Apparently, the problem could be:
spark plugs
carburetor
timing
vacuum leaks
clogged fuel filter
bad fuel pump
distributor

Anything else?

I changed the plugs and the distributor cap, the wires are relatively new, the vacuum hoses seem fine, and I just cleaned the carb.

It was while I was cleaning the carb that I noticed something else... The idle seemed smoother when the air cleaner was off. As soon as I put it back on, the car's idle started getting rougher. What does this indicate?

Any help would be greatly appreciated!

Btw, the car is an '87 CRX DX, carburated, no ECU.

 

It may indicate that your air filter needs to be changed. That is my only guess as to why it idles better with the cleaner off.

 

Hmm... Kinda makes sense, but the air cleaner is pretty new and pretty clean. Worth a shot though.

Maybe it's a combo of things; I'm going to check my timing, recheck the vacuum hoses, and check the fuel filter too.