I have adjusted the idle on a 93 Accord LX several times to ger it to stay around 900, and each time I have had to adjust the idle up. My question is, what is going to happen when the screw won't come out anymore without falling out? Is there somehting else that is out of adjustment, possibly a bad IAC valve? Also this car surges from 900 up to 1500-2000 and back down again repeatedly.

 

check all vaccuum lines, and oil. are you getting a check engine light?

 

could have air pockets in the cooling system. that's been known to happen in honda engines. but that could be from a leaking head gasket too.

 

check for leaking intake gasket, vaccum lines and injector seals

 

Vacuum leaks should cause the idle to increase. nugen101's problem is he has to increase his idle often and will soon run out of room on the idle adjust screw.

There may be dirt, oil, or some other foreign matter restricting the air bleed passages, or the IACV screen is really dirty. A malfunctioning PCV valve could be allowing blow-by into the intake, causing the collection af dirt and oil.

Remove and clean the IACV, the idle screw, and whatever else you can get at easily. Check out the FIV too. The surging is most likely caused by a leaking FIV, assuming you have no air in the cooling system.

When you put it all back together, the idle should be adjusted with the IACV unplugged, engine at operating temp, and no accessories turned on. You want a base idle of around 650 to 750rpm, (I don't know the exact base idle spec for your engine). When you plug the IACV back in, the ECU should be able to raise the idle to whatever the spec is for your engine, and hold it steady. A misadjusted or faulty TPS can also cause problems with the idle, but for now, check out the simple easy fixes first.

Good luck.

 

i have suffered the same occurances, Air bubbles in cooling system, and faulty IAC valve. The air bubbles are simple to fix, via the breather valve. however the IAC was pretty tricky because even after fully replacing my throttle body and all sensors (i know its overkill). it was still throwing out a code and giving me problems at times. My advice is to check the wiring of your sensors, that is what was wrong with mine. now it runs fine, minus the clogged catalyst system.

 

Is there any easy way to check the intake manifold for leaks?