high idle, please share your knowledge!!!

[lakini]

after the 92 metro warms up, the car idles to high. Every once in a while, it will come down. But usually it stays up there. I think this might even be a reason I failed emmisions. The guy(inspector) kept trying to kick it down, but it continued to idle to high.
I pulled the little rubber plug (driver side) out under the air cleaner & tried to adjust that screw. It would idle higher, but the screw would not turn in the direction any further to bring the idle down. I'm not even sure if that is the problem.
I hear people mention tps switch's & pcv valves on other forums. I don't know what these are or where they are located, and if they can even be the problem.
Once again, I'd appeciate any input. I need help!!!! Thanks Guys for sharing your knowledge.

[crazyinkc]

The PCV (Positive Crankcase Ventalation) valve is located between the air cleaner and the valve cover in the intake manifold. You should see a hose coming off the valve cover over to the air cleaner and it "T's" to the intake. The PCV valve is held in by 2 phillips screws and a small bracket. remove the hose and screws and replace the valve. My firts 92 had the plunger gone out of it so it had a large vacuum leak.

[mcalvo]

Lakini:
Some metros.. like mine (96 4dr 1.3) comes with an idle motor, I do not know for sure if it is a mechanical motor dough. This thing is responsable for a tictictic sound when your engine try to get back to idle state when the engine temperature is warm. At the beginning, I thought it was an electrical leak. Check out if your idel motor is ok.

Hope this helps,

MC

[graywebdesign]

My 94 1.0 with auto trans has a similar problem. I temporarly fixed the it by pulling off the small hose from the throttle body that comes from the Idle Up Solenoid and then plugging up the small vacuum pipe with a rubber cap. I also plugged up the open end of the hose to keep the inside of the solenoid clean. After doing this, my idle speed dropped to a normal speed, possibly even too low. The purpose of this system is to allow the ECM to increase the idle speed if it detects that either the parking/ headlights, the blower fan, the radiator fan, the stop lights, or rear window defogger are on. If after you try this, your idle speed is too low, you can probably raise it with the small screw on the side of the throttle body.

Hope this helps.

[graywebdesign]

Just some additional info on my 94 Metro 1.0. Since I also have air conditioning in the car, the factory also installed a second idle up selenoid in parallel with the normal idle up selenoid. So either one can increase the idle speed by letting more air into the intake manifold. This action is also controlled by the ECM. However, the previous owner had already disconnected and plugged up the lines for this selenoid. Apparently, he was also having a problem with idle speed. My 94 Metro has 106,000 miles on it.

[Crvett69]

is there a black rectangular box on the rear of the throttle body with a 4 wire plug on it? if there is thats your idle control moto. you can unplug it when its cold and idle is low and it should stay at the lower speed after it warms up and then you can use the screw to adjust for idle speed you want. also on one of mine it was having a similar problem and it was the sensor with the green plug on the throttle body that measures the water temp.
it was bad and after the car warmed up the idle would go up and down a few times then stay high

[lakini]

Thanks for all the info. I'll get on it.
I have an additional problem which I am not sure is related. I am only getting 25-27 miles to the gallon.
I have a bad exhaust leak which I'm fixing tomorrow, and the Converter is shot too.(also getting replaced tomorrow).
I am trying to figure out what is eating my fuel. The car runs fine. Can an exhaust leak and bad convertor be sucking fuel?

Dave (lakini)

[Crvett69]

if the convertor is plugged or mostly plugged it will make fuel mileage go bad in a hurry

[91metallicblue]

Here's a quickee band-aid solution that worked for me: remove your air filter, and see if there's a hole somewhere on the bottom of the filter case. If there is, turn on the engine then go to the hole and cover it with your finger. If the idle speed goes down, then you can simply put a piece of electric tape over the hole and it will run nice 'n quietly. Yes the 'source' of the problem(likely a faulty part) will remain, but if you were desperate to quiet that darned idle, it's a cheapie solution

[larry221]

Originally Posted by 91metallicblue

Here's a quickee band-aid solution that worked for me: remove your air filter, and see if there's a hole somewhere on the bottom of the filter case. If there is, turn on the engine then go to the hole and cover it with your finger. If the idle speed goes down, then you can simply put a piece of electric tape over the hole and it will run nice 'n quietly. Yes the 'source' of the problem(likely a faulty part) will remain, but if you were desperate to quiet that darned idle, it's a cheapie solution

Hey

My metro reacts exactly like this as it too has a fast idle problem and if I cover up that little hole under where the air filter would sit it idles down. But what is the REAL problem here does anyone know.?? I cant adjust the idle down any lower with the adjustment screw?

[mcalvo]

The hole you are covering has in the other side of the host, the PCV (positive crank valve) which helps your engine reciclyng gases. This valves acts just in one direction. If it is too dirty or in bad condition, would considerably increase gas consumption.

It is a "must do" and incredible $5 repair.

Hope this helps.

MC


BTW, by this time, I sold already my metro. I really miss its 35mpg. The monster I got gives me just 13mpg... Good deal dough.

[Creosote]

I had quite a time with this very same problem, High Idle and Poor Mileage.
The problem in my case was that coolant must circulate through the top of the throttle body ,that is where your coolant temp sensor for the ecm is located. mine had a piece of rtv silicone lodged in the throttle body that stopped the coolant flow and thus the sensor never sent the signal to the ecm that it was warmed up and the flow of fuel could be moderated.
It took a small diameter wire and a good half hour or more to feel the plug and fish it out.
I recommend anyone with high idle check the hoses and the Flow through the T.B.
Best Regards, Creosote

[popup]

In my case it was a vacuum leak in the vacuum hose that goes to the brake booster.

[geojim]

To elimate a leakly vacuum hose possibility, go down to your local parts store and buy 2 feet of every size vacuum hose they have. Should not cost but a few bucks. Change all the vaccum hoses under the hood; there are not that many. Then you can elimate that as a potential cause.