86 accord idle help

[Slipknotcraig133]

i have an 86 accord lxi f/i. It will sometimes idle at like 250 and sometimes it will idle at like 2 grand. does this sound like a sticky throttle body to you guys?

[shepherd79]

nope, it sounds like faulty O2 sensor, or EGR valve. does ECU gives you any codes?

[smufguy]

i have an 86 accord lxi f/i. It will sometimes idle at like 250 and sometimes it will idle at like 2 grand. does this sound like a sticky throttle body to you guys?

1) like alex said, check to see if your ecu throws any codes

2) when was the last time u changed your fuel filter?

3) check the cables goign to the alternator

4) open the fast idle valve cover and see if you hear a hizzzzz. if u do, get another one from the junkyard and replace it.

5) spin the tb and see if its hard to rotate, if it is, open up the piping to the TB and clean the plate and the mating surface, first with just a cloth or paper towel and then with a high penetrating cleaner like a carb/TB or even Brake parts cleaner. Gasoline works good too.

[3rdgeneration]

i also have an idle problem when i warm up my car it revs up and down instead of idle,, what do u think this could be?

[shepherd79]

if the car idles speed goes up and down after it warms up it could be a few things.
1. O2 sensor is faulty
2. EGR valve is faulty
3. Fast idle valve is faulty.

I would start with fast idle valve. it is easy fix. Locate the fast idle valve. it is on the back of the TB. it will have two coolant lines connected to it. remove the two top screws that hold the top. don't worry nothing will pop out or anything like that.
now start the car, it should be warm by this time, and with a big wide screw driver adjust that big screw that is inside. in your case you should go clockwise. while you are adjusting make sure you count how many turns you made, just in case it won't solve the problem. this way you can put it back the way it was. If the RPM went down and the car idles smooth, you are on the right track. adjust it just at the point where the car idles good. you may have to readjust the idle screw after that.
your next step would be to wait till the car cools down and start the car when it is cold. if the fast idle is above $1400-1500 RPM, adjust the same screw clock wise. it will lower the fast idle RPM. adjust to where it should be.
i hope that helped.
let me know if you need more help. IM me anytime.

[Oldblueaccord]

[QUOTE=shepherd79]if the car idles speed goes up and down after it warms up it could be a few things.
1. O2 sensor is faulty
2. EGR valve is faulty
3. Fast idle valve is faulty.......

Shepard I dont know where you are getting this from? O2 egr have nothing to do with idle

from the book Honda service manual printed 11/88 p 12-38, 12-39

Symptom: when cold: Fast idle speed not as specified 1200-2000 rpm

1: Fast idle valve page 50

2: Electronic air control valve page 40 (I think this is it myself)

3: Idle adjust screw page 51

end quote




No where does it even list EGR O2 as a fault on this chart

That Eacv is a POS they did away with it. Not even sure 86 had it but there not very accurate with there idle control. Its attached to the manifold between the fuel rail and manifold. It has a 2 pin conector.

Symptom: When warm,idle speed above spec. rpm

1: Hoses and connections (vacuum leak i'd guess)

2: Fast idle valve

3: Eacv

Eacv resistance should be 8-15 ohms

Also on page 12-50 Fast idle control Inspection:

1: Start engine ( doesnt say cold but I would assume)

2: Remove cover of fast idle valve

3: Put your finger on the valve seat area and make sure that there is air flow
with the engine cold (coolant temp below 86 F) and idling.

If not replace.

4: warm up engine

5: Check that the valve is completly closed. If not air suction can be felt in the valve seat area. Any suction felt valve is leaking replace and recheck.


Let us know how you made out.

Edit: does'nt hurt to clean the throttle body out either i do mine once a year

wp

[86LXItooFAST4me]

does it idle fine during warm up?

[Oldblueaccord]

does it idle fine during warm up?

ANother thing I forgot was your throttle cable maybe a little to tight. I had mine adjusted last year after suffering a high throttle condition only in the hottest months here in TN. The idle would stick at 2 grand almost daily. I could pull back on the throttle manually and it comeback to normal. Somehow the cable must have been to tight and only when really hot days in traffic it would show up. Took a good Honda mechainc to spot the problem. I suffered thru it about 8 years LOL.

wp

[rjudgey]

if it's bouncing up and down to 2K most likely the fast idle valve, try adjusting it, and also cleaning it out, they get full of crap!! a good way of elimintating it is to cut some cardboard up, and put it inbetween the manifold and the valve, then you will have to run the engine with your right foot untill it is warmed up then it won't stall, if it idles perfect it's that, if it's still doing the same try the O2 temp sensor inthe inlet manifold, un plug it and it should trwo ECU code but the ECU will use a fail safe setting and it will run perfectly, had this happen to mine had me baffled for ages, it also makes your engine run really rich at idle so check yourplugs if they are black then your engine is getting bad readings from sensors and is running rich, try unplugging each sensor and see how it runs, also pull out a plug clean it, then put it bak in and run for a few mins and pull it out and see if it;s still clean or black again.

[wknox]

where is the Fast Idle valve located excactly on the engine?

thanks
willie

[shepherd79]

[QUOTE=shepherd79]if the car idles speed goes up and down after it warms up it could be a few things.
1. O2 sensor is faulty
2. EGR valve is faulty
3. Fast idle valve is faulty.......

Shepard I dont know where you are getting this from? O2 egr have nothing to do with idle

from the book Honda service manual printed 11/88 p 12-38, 12-39

Symptom: when cold: Fast idle speed not as specified 1200-2000 rpm

1: Fast idle valve page 50

2: Electronic air control valve page 40 (I think this is it myself)

3: Idle adjust screw page 51

end quote




No where does it even list EGR O2 as a fault on this chart

That Eacv is a POS they did away with it. Not even sure 86 had it but there not very accurate with there idle control. Its attached to the manifold between the fuel rail and manifold. It has a 2 pin conector.

Symptom: When warm,idle speed above spec. rpm

1: Hoses and connections (vacuum leak i'd guess)

2: Fast idle valve

3: Eacv

Eacv resistance should be 8-15 ohms

Also on page 12-50 Fast idle control Inspection:

1: Start engine ( doesnt say cold but I would assume)

2: Remove cover of fast idle valve

3: Put your finger on the valve seat area and make sure that there is air flow
with the engine cold (coolant temp below 86 F) and idling.

If not replace.

4: warm up engine

5: Check that the valve is completly closed. If not air suction can be felt in the valve seat area. Any suction felt valve is leaking replace and recheck.


Let us know how you made out.

Edit: does'nt hurt to clean the throttle body out either i do mine once a year

wp

Where i get all that info?
It is from my own experience. I found that half the time honda shop manual is wrong.

the fast idle valve is located behind the throttlebody.