1987 accord idle problems

[pete180]

My friend has an accord with around 60,xxx miles and when he bought it he was told it had been parked for quite some time. After the purchase he noticed that when he would drive it for a good amount of time it would start to idle really high. It sometimes would idle so high that it would not turn off after you switched the key in the off position. We checked the vacuum line to see if any were disconnected but not were found. I doubt it has anything to do with the carburetor idle/mixture screws because it only does it when he drives it on the highway. Does anyone have any idea what it could be??? .. Carb

[A20A1]

You have a high idle problem which is causing your car to diesel

It's not the idle mixture screw... in most cases if you didn't remove the cap or adjust the screw then there is no way for it to fall out, and it hardly ever unscrews itself.

Check the basics first like oil and coolant levels.

I believe you have a vacuum leak and it's causing your idle diaphragm to constantly up the idle speed. If it's not a vacuum line, the vacuum leak could be from a gasket or a stuck thermovalve.


Other ways you can get high idle:
- The carb is dirty causing the throttle to stick
- The cable is causing the throttle to stick

[pete180]

Is there any other way to check for leaks without the pump? How do I check the thermovalve and where is that located?

[ACCORD1.8CARB]

when your car isnt reving high what does it idel at? and when it is how high does it get? i have sum what the same prob. i was told get a new carb if will fix alot. is your new,rebuilt?

[A20A1]

Yeah what is your average idle speed?

As for checking for leaks, use carb cleaner while the car is running, spary the cleaner in small areas at the vacuum line connections and at any of the gaskets, between the carb and manifold, and manifold and cylinder head. Be carefull not to let the spray enter/get sucked into the carburetor.

What you are listening for is a change in idle speed, if there is a vacuum lean the vacuum will suck up the carb cleaner and the idle will fluctuate... problem is the idle will fluctuate if the carb sucks up the cleaner through the barrels which is why you should be careful not to spray into the barrels of the carb, or you'll get false feedback.

The vacuum gauge is good cause it can tell you a lot about your car and can see if there are faulty valves or other engine problems.

[pete180]

OK at normal rev its at 800-900
it peaks to around 4000 sometimes when its acting up
Im would have to say its not rebuilt im not to sure on that one
I found this vacuum gauge is this what I need and were are the test ports that I plug it into.

[A20A1]

Yes thats good.

[pete180]

It turned out to be 2 cracked vacuum lines and some sludge buildup. Thanks for all the input guys

[A20A1]

It turned out to be 2 cracked vacuum lines and some sludge buildup. Thanks for all the input guys

Thats good to hear.

[3rdCoast]

dont mean to steel the thread but my car is actin up like this it sounds like. Everyday i drive maybe total of 6mi. round trip to work maybe another 2mi. round trip to a friends house. Today i took my brother to his friends house and was stuck in traffic so i was on the road longer. I stopped by my work to get a drink and bullshit with some co-workers a min. Then when i started my car back up and let it run while i went to the soda machine the fans were on. I get back in the car and start to drive and my idle was bein crazy. When i come to a stop car idles about 1000rpms. but if i let go of the brake it will coast its way up to 1500rpms and put itself through 1st gear without touchin the gas pedal. Id im coasting to a slow down for ex. a light it will go down to 1500 rpms but when it trys to go below it will surge back to 2000 untill i put the breaks on then we are back at about 1000rpms. I dont have a vac. guage so it makes it a lil harder for me to figure this out. I know i have other threads goin about my car problems and they might all be tied together somehow. I do have a couple vac hoses disconned and pluged with screws. i can get u the hose #'s if that will help they were like this when i got the car. My problem seams to be heat related cuz i dont drive much daily so i doesnt have much time to heat up all the way and it hasnt done this latley.

[A20A1]

For now try and adjust the idel diaphragm screw... it's on the passenger side of the carb and it faces the valve cover. Turn the screw out and lower the idle.

Yes please list the vacuum lines that an plugged or unhooked.

[3rdCoast]

hose #'s 20 and 32 r disconnected and plugged with screws. I cant find where hose 20 connects at all and isnt long enough to go to anything behind the carb. may have been cut shorter i dunno.

[A20A1]

Hmm, I'm not sure where 20 goes... I can't even find it on the diagrams. 32 goes to the solenoid on the dirvers side of the car somewhere above the tire.

Anyway to get a picture of the hose #20 location?

[3rdCoast]

well is 32 important or can it be left alone? As for the hose 20 i think its connected to somethin on the passenger side fender i'll try to find out where and what it is. Im screwed in the picture dept. I dont have a digital camera and i dont know anybody that does

[3rdCoast]

anybody???????

[A20A1]

Strange... on the canadian rig I got #20 is plugged on the metal vacuum lines.

Anyways connect the #20 vacuum to the #20 port in the picture... if #20 is from a solenoid.... it may begin to click.

As for #32 I marked to metal vacuum lines above the driverside tire.

[A20A1]

The line marked "Cruise Control" also uses a #32 vacuum line

The line marked "???" is also a #32

The line marked "Top A/C port" is a #30 vacuum line

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[3rdCoast]

are those connection photos of the lines on the back of the carb or somewhere else??? Im gonna try to find them. thanx

[A20A1]

the first pic is the left side of the carb (passenger side)

the second pic is the right side of the carb... but above the wheel well... (drivers side)