hello, I am here to try and solve what is causing my low idle.
so far i changed my o2 sensor, wires, plugs, cap and intake to spectra intake.

i went through some cel trouble when my o2 heater came apart. also it was wired backwards.. around that time i had put in some fuel system cleaner (gas tank).

i just got my o2 wired correctly last night and my car throws no codes now =]
but my idle is still ****..

heres the rundown:

i start my car and let it warm up. during this time it idles just under or over 1000 rpms. (fitv +) but as it warms up my idle drops, really drops. usually to 0 rpms.. my car never dies when it idles like this and it doesn't really shake either.

since fixing my o2 sensor last night, the car was idling right off and on. it seemed like the idle would stabilize for awhile after i revved it into high rpms in first gear. something else that puzzles me is randomly my rpm gauge will jump up on acceleration, or lag then drop on deceleration. this doesn't happen to often, but it gives me nightmares of a failing alternator (hahaha)

what i am asking is, does it sound like it would be the iacv? or the fuel injectors? or the egr?? not sure what the egr is yet.. haha

Thanks for reading and trying to help me out. I am learning =]

also, i just bought a 92 accord automatic for $150 from a friend. it runs, but not the best (tranny, gaskets). using it for parts and experiments haha

 

First, the bottom mark on the tachometer is 500 rpm, not 0 (if it were idling at 0 rpm, it wouldn't be idling, the engine would be OFF). I don't believe the O2 sensor has much, if any, input at idle, the control is just trying to maintain correct idle speed.

EGR is Exhaust Gas Recirculation. The valve is on the right end of the intake manifold just behind the head. There is a single vacuum line to the side and an electrical connector on top. It should be closed at idle.

I suspect the iacv. Does the idle speed up if you turn on the A/C? Or turn on a lot of electrical accessories (headlights, high blower, etc) at the same time? The control is supposed to know when the A/C is on and senses electrical load to adjust idle accordingly. Do a search on checking and cleaning the iacv.

 

so i went to check if electrical loads change the idle. and if anything, the loads make it go lower.. my a/c doesn't work, so i just turned on my lights and blower. i also have a squeaky belt on startup and when i have my lights on going from a stop it squeals.

i will take iacv off on my next day off to clean it. hopefully it helps.

thanks

 

the idle should be like 700 rpms i think off memory (+ or - 50 rpms). its probably a bad tach with the irradic jumping that you mentioned. it will require a scope to test the pulses coming from the distributor to the tack itself to find out. you may be able to use a special tester tool for this also. let me go see what it is called again. (i havent used it in a while) BRB....

 

its a dwell/tach/volt meter by actron. available at autozone i believe

 

thanks, i will look into it.

another thing i should mention is my idle screw is stripped out.. someone obviously tried to fix something the wrong way..

i am going to hopefully figure out the iac screw when i clean the iacv. any advice to get it loose/out?

thanks for all the help.

 

an easy out bit. i have reverse threaded drill bits from matco that work well though. if you dont have them just use the easy out bits

 

okay so today i unplugged the iacv while the engine was on, and it almost died.

since it didn't die, does that mean i have a vacuum leak?

i plugged it back in a couple of seconds afterwards, so it could have died if i left it unplugged longer?

i still plan on cleaning it, just not until monday =/

and about my idle more, the tach drops as far as it will go, wresting on the bottom "0" line. i'm guessing it is idling at around 4000 rpms since it doesn't shake to horribly? any input?

also does anyone have a link to some good pictures of where the adjustment and pivot bolt are on the drive belts? (adjustment pinch bolt??) the pictures in haynes don't help to much.

thanks a lot for all the help from the members here!

 

something to add, i tryed adjusting my idle screw, which i was able to once i got the right screwdriver. i did it as the haynes says, but once it started to go higher, the engine would start cutting out/surging. ?? after i adjusted to 500 +-50 rpms and turned it back on after hooking iacv back up, the idle goes from 900-500 rpms up and down over and over.

any help is greatly appreciated. Thanks

 

fast idle valve is bad. very common. also check the iacv and the coolant lines to these parts. check that they are not clogged and that you dont have a coolant leak or low coolant. and be sure you bleed your coolant system good.