92 Honda civic idle fluctuating wildly.
 

I have a 92 civic, amongst the pile of problems with this car a new annoying one has arisen. My car revs from 1000rpm-3000rpm while in neutral, or when the clutch is in. I replaced the IACV valve and it's still the same. With the two holes in the throttle body after removing the big black arm thing that holds the pod filter, covering the bottom hole makes the problem go away. Does anyone know the problem?

Known problems :

fried piston rings.
Radiator not working automatically.
engine has high revs usually (due to cold engine from radiator manually always being turned on)
Also engine has as far as I know, no coolant, just water. Lol.

Re: 92 Honda civic idle fluctuating wildly.
 

could be your throttle position sensor... or a hole in a vaccum line... i have the same problem in my 98 s-10 and cant find it.

Re: 92 Honda civic idle fluctuating wildly.
 

Pretty sure it's not a hole in the vacuum line, where would I find the throttle position sensor?

Re: 92 Honda civic idle fluctuating wildly.
 

Attachment 103471
this will fix your problem. on one side theres a plate with 2 8mm screws and the other has a small thermstate. most likly the side with the two screws is your problem. open it up and you will see a bulb just take a flat head and wind it down till tight. and all fixed have fun.

Re: 92 Honda civic idle fluctuating wildly.
 

Thanks for that bluhonda, good tech answer!

Re: 92 Honda civic idle fluctuating wildly.
 

you are welcome

Re: 92 Honda civic idle fluctuating wildly.
 

I would also check and make sure your coolant temperature sensor is working properly. If it is malfunctioning than it could be telling your ecu it is running at a low temp. So then it will tell you ecu to make you rev high to heat up.

Bad clutch and/or master cylinder?(just a thought)

Re: 92 Honda civic idle fluctuating wildly.
 

Idk, does it help if I say it revs in gear aswell? Like my car can drive for a bit with no foot on accelerator.

Re: 92 Honda civic idle fluctuating wildly.
 

That still kinda sounds like the coolant temp sensor.

Re: 92 Honda civic idle fluctuating wildly.
 

Still having problems with it, now it's starting to **** with my clutch, car revs high, but takes a bit for acceleration to catch up. How would I go about changing this sensor?

Re: 92 Honda civic idle fluctuating wildly.
 

It is located on the head. I could be mistaken, But I want to say it is underneath/next to the Distributor. It could be on the other side though. Ill take a look on my car, when I go out for break.

http://cgi.ebay.com/ebaymotors/ws/eB...m=180571952724

There is a link to what it looks like. It is very easy to replace. Rather cheap too. Lemme know of any other questions.

Re: 92 Honda civic idle fluctuating wildly.
 

sorry guys i know this is not a related to this thread...but how do i start a new thread?

Re: 92 Honda civic idle fluctuating wildly.
 

Once your at the default location(Im guessing 1st - 5th gen section)
https://www.civicforums.com/forums/184-1st-5th-gen
At the top of the forum listings there is a blue botton. It should say 'Thread' or 'New Thread', It will be located by the page number selection.

Re: 92 Honda civic idle fluctuating wildly.
 

thanks..i figured it out... it would be nice if somebody posted a reply on how to help my problem tho hahaha

Re: 92 Honda civic idle fluctuating wildly.
 

dont forgot to back it out 180deg after you tighten the termo down otherwise it will malfunction as well. But yea a fit valve was my guess as well.

Re: 92 Honda civic idle fluctuating wildly.
 

under the dizzy its the only clip plug in there and its a 17 or 19mm bolt in sensor. i am almost 100% positive that is not your problem though. If its winding your rpms up 9 out of 10 times its a vaccuum leak. Low idle would indicate fuel or coolant issues. If your not throwing any CEL then its most likely not a elec or sensor problem.

Check your fast idle thermo valve
check all vacuum lines on the intake to and from
check your idle adjuster screw
check your timing even
also resetting your ecu couldnt hurt
but im almost 100% that your problem will lie in a vacuum line or port, best of luck to you though.

Re: 92 Honda civic idle fluctuating wildly.
 

also check the tb gasket.....thats honestly what it sounds like to me, when you replace it take some 220grit or whatever and make sure that the plenium surface and tb surface and hella clean.

Re: 92 Honda civic idle fluctuating wildly.
 

My 92 civic si had this problem several times. The first time I ended up getting a new throttle body at a junk yard and that fixed it. The trouble code indicated TPS sensor which is riveted to the throttle body. The second time I had problems with the cooling system. If you have a coolant leak, clogged radiator, or bad water pump- the idle will be jacked. Also, after draining the coolant, you need to burp the system to get all air out of the cooling lines. Typically, bad sensor trigger trouble codes, but a bad radiator, water pump, vacuum leak or air in the cooling system will likely cause a hunting idle without triggering a trouble code.

Re: 92 Honda civic idle fluctuating wildly.
 

I would look at the ICA valve again...did you replace it with a new one or a salvage part...(or Ebay)...fill it with carburator cleaner and let it soak for a bit then flush it with more cleaner until it runs out clear...make sure O-rings are in place