Alright guys i have a 1988 civic lx.
ive done hours of researching and still havent been able to solve my problem.
i took off my iacv and cleaned it. but that hasnt seemed to solve my problem.
my car idles at 3,000 rpm after warmed up.
drops to 2,000 and shoots up back to 3,000.
and wut is weird about this is when my cel comes on.
all of it stops and my idle drops back down to 800.
can someone please help me figure out this problem.
it is juss too annoying to bare with and i hate how at every stop light
someone thinks im trying to race them.

p.s.there is also no vacuum leaks.

 

Have you pulled the codes?

 

No i havent.
sometimes when it does it
the cel never comes on!
and it juss does it forever.
even if i shut the car off and turn it back on.

 

the check engine light doesn't need to be on to access the codes - whenever you get a check engine light, the code(s) are stored in the ECU and remain there until you reset the ECU - when you turn off the ignition, the check engine light goes away until another (or the same) problem is detected but the codes from previous CELs remain in the ECU

sounds to me like you have a vacuum leak somewhere causing the high idle - if you unplug the EACV with engine running, the idle should drop down to around 500 and remain steady - when you do this, you will get a check engine light and code 14 for EACV and you will need to reset the ECU after plugging the EACV connector back in

 

alright i didnt know that.
well i took it to my friend whos a mechanic.
to check for vacuum leaks and he wasnt able to find any.
and i unplugged the iacv while it was running.
and the rpm didnt drop down at all.
the car juss stalled and stopped running.

 

Is your TB sticking at all?

 

no not at all. =/

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jlicrx &raquo;</TD></TR><TR><TD CLASS="quote">the check engine light doesn't need to be on to access the codes - whenever you get a check engine light, the code(s) are stored in the ECU and remain there until you reset the ECU - when you turn off the ignition, the check engine light goes away until another (or the same) problem is detected but the codes from previous CELs remain in the ECU

sounds to me like you have a vacuum leak somewhere causing the high idle - if you unplug the EACV with engine running, the idle should drop down to around 500 and remain steady - when you do this, you will get a check engine light and code 14 for EACV and you will need to reset the ECU after plugging the EACV connector back in </TD></TR></TABLE>

he stated there was no vacumm leaks... and that when the ecu throws a code its all good after. its deffinatly a sensor/electrical problem. i would check the TPS out put with a volt meter... 3 wire set up... 1 pos 2 neg 3 signal.. withe the throttle closed it should read 0.5V and at WOT its should read 4.5 or 5.0 volts

 

yea i was thinkin it was a sensor too.
also maybe the map sensor?
ill check out the tps n see wuts up with that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tico &raquo;</TD></TR><TR><TD CLASS="quote">

he stated there was no vacumm leaks... and that when the ecu throws a code its all good after. its deffinatly a sensor/electrical problem. i would check the TPS out put with a volt meter... 3 wire set up... 1 pos 2 neg 3 signal.. withe the throttle closed it should read 0.5V and at WOT its should read 4.5 or 5.0 volts</TD></TR></TABLE>

agreed. i would start with the tps as mentioned above. if that doesn't reveal any problems... it may be the fuel vapour purge control. (i don't know the proper name for it) A friend of mine had this issue and we found that the purge control was sticking open, acting like a vacuum leak. have you pulled the code to see what sensor is malfunctioning?

 

check the f.i.t valve,

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by av1bseries &raquo;</TD></TR><TR><TD CLASS="quote">check the f.i.t valve, </TD></TR></TABLE>

the Fast Idle Thermal Valve would not be contributing to this issue. It's a mechanical device, with no connection to the ECU. We've established that this is an electronic/sensor issue.

 

not to mention his car doesn't have a fitv

 

i am takin my car to the shop today to check if its the sensors.
hopefully i figure this thing out. thank u guys for the info.
ill let yall know wut happens.

 

ok takin my car to the shop was a fail. dudes tried to charge me 160 just to look at my "obsolete" honda thats what they called it lol.

 

did you look at the ecu for codes? it sounds like the iacv is bad to me. even if the cel light is not on the ecu will store them

 

yes i took off the iavc and cleaned it. and when it idled high to 3,000 rpm i unplugged the iacv and it just stalled.

 

if the iacv is bad totally like not working cleaning it wont do anything. any codes at the ecu??

 

i got the codes. blinks 6 times pause then 14.
answers for these codes?

 

One simple look in the FAQ -

http://fourthgenhatch.net/helms-ecucodes.html

 

6
Accord Civic CRV CRX Del Sol Odyssey Prelude
85-98 86-98 97-98 85-91 93-97 95-98 85-98 ECT Sensor (Engine Coolant Temperature)
defective circuit or unplugged / defective sensor


14
Accord Civic CRV CRX Del Sol Odyssey Prelude
88-98 88-98 97-98 88-91 93-97 95-98 88-98 IAC Valve (Idle Air Control)
defective circuit or unplugged / defective sensor

 

cool i juss pulled those codes right now. how much do u think it is for a new iacv and coolant temp sensor?

 

CTS is cheap. Under $15. Toss one in first and try that. It very well could be the whole issue. It's sending a signal that your engine is always cold, so it bumps the idle. Just an idea. A cheap one.

 

new at autozone iacv is 249.00 lol, i have a used one
coolent is 27.00

 

249.00?! wut tha [freak]. lol [freak] that ****. ill buy the sensor first see what that does.