I have a 91 hatch dx that is idling fast while cold and warm. I have changed out the AICV valve with a used one, though i'm not sure if that one is good either. I changed out the coolant temperature sensor as well as replaced the ECU with a used one. I don't have a check engine light on, but my ECU is blinking twenty short flashes. I'm not sure what else to check. Does anyone know what the twenty flashes means? any help figuring out the fast idle would be appreciated!

 

code 20 is for electric load detector - sometimes indicates an alternator not working correctly - reset the ECU and see if it goes away

very high idle is usually caused by a vacuum leak

 

I've tried to reset the ECU and it always comes back. I even changed the ECU with a used one and it keeps coming back with the same code. . On occassion my head lights will go off though. it's freaky when you're driving down the road at night and they just all of the sudden go off. all i have to do is turn them off and back on and that usually makes them go back on which makes me believe that the switch on the left is what is wrong with it. another weird thing is that's now happening is that on occassion if i have the lights on and i come to a stop and turn the car off, occassionally the left side marker light will stay on, once again, jiggling the light switch makes it go off. I'm starting to think that that's where the light blinking is coming from. now my question is, would something like that cause a fast idle as well? im going to try to change out the switch sometimes soon, just can't any time this week plus i have to figure out if the one from a 93 hatch will fit the 91. i'm thinking it will since it the **** looks the same. if not i have to make a trip to the junk yard. as for a vacum leak. i've sprayed just about everywhere on the engine bay and around the throttle body with starter fluid to see if i could find a vacum leak and no changes in idle. I did take the house coming from the AICV valve and felt for a leak and was able to feel a good pull on it when i put my finger in it. if i let go and opened it up to air, it would idle even higher. that make me think that maybe the it's not the AICV valve since when i close off the hose that it supplies it continues to idle fast making me think that it is staying closed, but honestly i don't know much about how it really works so i'm not exactly sure. it seems like whenever you have a fast idle most people will assume it's the AICV valve. does anyone know how to check if your AICV valve is bad other than putting a new one? (i'm assuming that there's always the possibility that the one i put in since it was used was also bad?)

 

I forgot to mention that the car is a manual, and when parked it's idling fast, but when i'm driving it goes back down to a normal idle. i've been sitting at lights with the clutch slightly engaged in order to keep the idle down. i'm not sure if that shed's more light into the problem.

 

start it up and unplug the connector from the EACV - if the EACV is working right, the idle should drop down to around 500rpm and remain steady - if the idle stays high, the problem is not with the EACV, unless it is leaking vacuum - did you replace the figure 8 shaped rubber O-ring gasket when you put it back on?

 

I'll try unplugging the EACV while cold tomorrow and let you know what it does. . i want to say that i've tried unplugging it before, and it did not drop the idle but it started doing a pulsating idle where it idled faster then slower.. then eventually it started idling fast.. if i'm thinking right, your thought is if the engine is cold the EACV should be compensating by giving more air to the system when the engine is cold. . i'll def check it again, as for the figure eight shaped rubber oring gasket. i did not replace it since i did not have one. . where can i order one cheaply? now i did the cheap mechanic fix, and put a very very slim, but even bead of gasket sealer around the gasket as a cheap fix. I have heard that if that leaks that can be the source of a leak as well. Does anyone out there know where to order one?

 

# 19 in the pic, just under $2


http://www.hondapartsdeals.com/hpa_p...onGroupID=6229

 

I would think this would fix your issues +1

 

@ spug, thanks for the link, the schematic is nice,, i'll order the gasket and see what happens, ,, @ crxin, hopefully it does fix the high idle problem, what other problems you think that could be causing? and @jlicrx, I did start the car, and it had a fast idle, , i unhooked the EACV and the idle slowed down but it surged up and down.. the ECU was flashing one quick flash,, then fourteen (for the EACV), then twenty short flashes. after hooking it back up, and then taking out the hazard fuse out for a little while, I started the car back up again, and once again, fast idle with twenty short flashes on the ECU.. any wisdom from undoing the EACV? i'll order the gasket and let you guys know what it does, I feel that my small bead of gasket maker around both holes should of gotten a good seal, but not sure,, for two dollars though, i'm defenately willing to change that out. . ..