I have a Honda Accord 1996 with a 2.2L engine.
A month ago it started to have idle problems, the revs go low and the engine stopped. The problem did not happen always, some days the car was okey ...next day there again the problem. It was always when the car was already hot at its normal running temperature.
Mechanics here changed spark plugs, air and gas filters cleaned the injectors ... the problem was not solved but the problem changed to a fluctuating revs, the engine goes from 900 to ~ 1800 up and down constantly in NEUTRAL, when "D" was applied the fluctuation stops or it was not easy to feel.

So, after reading a lot from internet forums, I removed the IAC and the EGR valves and cleaned them with one of those "carburator cleaners", checked the vacuum hoses and finally removed the entire "Throttle Body" and cleaned everything I could see. I did not open the FIT valve, I did not know what it was at that moment.... but instead I removed a "black piece" fixed to one side of the body with one electrical connection (plug) and fixed through two small "line" screws, very difficult to unscrew. I guess this piece has some sort of internal circular spring and the holes for the screws are oval-shaped, so there is some sort of calibration involved when this piece is installed. I didn't see anything to clean here so I re-install the piece trying to put it at the same position it was.

Well, finally I re-install everything and the engine is okey but the revs are high:

At hot running normal temperature:
-In NEUTRAL it is about 1250 rpm.
-In "D" it goes down to around 900 rpm.
-When the Air Conditioning is turned ON the revs go down a little but recover.
-When lights or fan is turned ON revs goes down a little.
-With the engine running I disconnected this "black piece" I described before, and revs go up to 2000 rpm. So I re-connected it.

Engine cold in the morning:
It started okey with revs a little high and then went down to ~900 rpm... I am not really sure, but I think revs go up after a while when the engine reach normal running temperature.

What should I do to lower the revs to normal ? What is this "black piece" ? Should I clean and remove the FIT valve ?


Thank you

JR

 

Does the engine still stall? Or, is that symptom gone and now only has a high idle? Does the engine currently rev up and down or is the idle high and steady?

 

It only has a fast and steady idle.

Cold in the morning, the engine goes to 1500 rpm and when hot to the 1250 rpm in NEUTRAL, 900 rpm in "D".

By the way, Now I know the "black piece" is a sensor, the "TPS". I believe it has to be calibrated at 0.5 Volts with the throttle closed and 4.5 Volts WOT ??

Another thing... Around 5 years ago, the engine had also idle problem (revs going down and stalling) the mechanic closed the vacuum hose connected to the EGR valve and the engine was okey again. The hose is still closed. I cleaned the EGR valve which seems to be fine (moving softly). Should I re-open the hose ??

Thank you again

 

Those things you described are pretty much normal for all cars. It does that on purpose to make up for the new amount of load the AC pump puts on the belts. And the same for the lights or anything electrical. The engine revs so the alternator can maintain a constant power output. Since if there wasn't enough juice, you go and turn a few accessories on and the "sag" in power would stall the engine (because of not enough power to produce spark of power the fuel pump) At the same time, if certain electronics run without adequate power, they tend to short out or suffer from some other damage. Hence why when people put a large sound system in their cars, they need a capacitor or a second battery or else some of the larger amps burn out.


anyway
I Just bought a '92 and a few days after I drove it around, it did the same thing. I'm new to Hondas but not cars in general.

Went from around 900RPMs to about 1600RPM for a few seconds and back down for a few seconds repeatedly. put it in drive and it was fine. It has only happened once but i see that its a trend and would like to know too.

My guess would be for you to go and check all your grounds and battery terminals. If the engine components aren't grounded properly, it will cause all sorts of problems. If any of them look crusty or corroded. Clean them with a wire brush (battery disconnected first just in case)

Again I don't know if this is the solution but it helps anyways since older cars will have more corrosion and weak grounds as time passes.

 

hi,i had a similar problem too with my 90 accord..but mine had a manual tranny,when i first bought it,the idle would play alot(850-1500) when it was on operating temperature(nuetral) on gear it was ok. my co-worker told me it was my tps that was bad or dirty.so i took chances and went ahead to just cleaned my whole throttle body w/throttle body cleaner.i let it dried up,install a new gasket,installed throttle body,fired it up and let it idle till it gets hot and what do know the problem is gone...and that was the nite i won my first race with my cb7! lol..well i hope this info would shed lite on your cb7 as well gudluck.