introducing myself + ask for help

[mike_surrey]

Hello Everyone,

my name is Michal, l live near London and I drive black 2000 Focus 1.8 Zetec manual.

I have a problem with the car and I thought to ask for your help. My car is revving itself, usually straight when I start the engine. It is getting worse now, it revvs itself when no gear is selected also when I drive and press clutch it starts revving. Sometimes it stays within 2-3k but recently revvs to 4k - which is frustrating. The car accelerates by itself when in a gear (I don't touch the gas pedal). It sometimes stops doing that after I keep the clutch for one-three minutes and gets 'normal'. But recently, before going to normal, the revvs drop down too low so the engine almost stalls and then, after 3 seconds it gets to normal idle mode. I did the ECU reading which shown nothing. I have read on the internet that this could be Throttle Position Sensor or idle control valve sensor. Unfortunately my funds are limited so I would like for your suggestions without trying both. Thanks.

[Sponsor]

[mac.mogul]

Doesn't really sound like a throttle positioning problem, it sounds more likely to be a dirty IAC valve BUT it could also be a dirty MAF sensor.

Both of these are easy to clean but I'm not familiar with the 1.8 so hopefully someone can chime in with detailed instructions.

One thing you might do that could improve the condition would be to disconnect the battery for about 20 minutes and then reconnect it. This will reset the ECU to its defaults and could possibly remedy the problem, at least temporarily. It won't hurt anything if you try it.

[mike_surrey]

Thank you very much for suggestions -I am going to disconnect the battery and see if it helps.

[SonicZXIII]

i honestly would clean and oil your entire throttle body... the 1.8 im not sure if it has it but check for a TPS (throttle position sensor) sometime this will act up and cause it to rev uncontrollably. the other thing i can think of is the throttle cable sticking,

[Ian.Deasy]

The early 1800 had a calibration issue that would hold the revs up. Might be worth checking your car is running the latest software. That will involve a trip to a Ford dealer.
The other potential area of concern is the crankcase vent pipe to the back of the inlet manifold. It usually crushes in on itself then splits giving and air leak that leads to all kinds of errayic idling.
On top of that I would check the idle speed control valve. They are known for sticking, they are a bit of a pig to get too as they live on the underside of the inlet manifold, but if you can get to it they are only held on with 2 8mm bolts. Take it out and immerse it in brake/carb cleaner for a while, that usually frees them off, but while its off its worth checking eBay as you can pick them up new for around £40. I got one for my wifes 2.0 Maverick (same basic engine) and its been fine.