i have this issue with my 89 Civic LX its a 1.5 all stock no mods at all, but my idle is going from 800 to 200 and damn near choking it self out if i turn on the A/C it gets worse turn everything that takes power off and it idles normal for a bit then goes back to crap, i have been thru 2 Alternators, new plugs wires cap and rotor button, i have done a vacuum leak test, also a propane test (gave a little shot of propane to the intake car died immediately), took it to honda their master tech had it for 2.5 hours and couldn't figure it out, my diagnostic teacher cant figure it out, and my emissions at idle are ridiculously high but at 2500 rpms they are normal, and smell gas fumes like crazy at idle......im ready to blow this car up im at a loss here

 

My initial guess would be to start with the IACV/EACV since you say your idle is messed up. Have you removed and cleaned it out yet?

 

no i haven't but i just found something that said that even air in the coolant system can cause that with these cars, i recently changed my radiator and the problem started not to long after that so i checked it out and it seemed low so i ran it got all the air out the system and now the idle leveled out and i can run it with my AC on and not kill the motor, so i gotta seem if it acts up again, im praying its not the IACV(EACV) cause thats $200 to replace if cleaning doesnt help

 

I have had the same thing happen on two cars a crx and a civic. My problem on both cars was the coolant sensor (not the one for the gauge) was making my car very rich at idle, no check engine light on either car. Check you plugs. This may not help you at all, but it's worth checking.

 

all the plugs are new but so far it seems to be running better, this problem has been setting all kinds of random DTC's

 

the DTC's it was setting was O2 sensor, Fuel Injector, VSS and i know for a fact my Fuel Injectors are good

 

ok so im slowly getting closer to fixing this problem, now it has the rough idle between 700-500 rpm's and when i go to give it gas to drive it hesitates for a second then starts to move forward.....any ideas???

 

check the forementioned sensors, have u check ur fuel filter or pump?

 

fuel filter is only a couple months old and fuel pump are not known to partially word they either work or quit working your lucky it you get a few seconds notice if that goes out lol

 

not neccessarily true, on my old car it was bogging out, hestitating and randomly shutting off for a month before i figured out it was the pump

 

mine doesnt randomly shut off tho i have had it choke itself out before from the low idle for to long

 

alternator? fuel pump?

 

Check your grounds. Would be worth checking since you said anything that draws power makes it worse

 

x2 on the fuel filter... Mine was clogged to no end and it caused bad idle... I am just saying...