revs stuck on. very high!

1. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

   #1 1st December 2009, 19:55

   Just pulled into my garage and revs stuck on at same as what it was when I pulled in. Then when I pressed throttle it went up more and stayed up, then after a couple of seconds went back down to normal.
   I had my cambelt done over the weekend but all seems fine there I think. Engine and oil temp about normal. I know I'm goin to need a HG soon as I have a very slight leak I think. Could this be the prob or is it maybe ICV or temp sensor?
2. Mochachino Saxperience Hardcore! Joined: Nov 2007 Guantanamo Bay Posts: 28700 oyster card

   #2 1st December 2009, 19:59

   I thought temp sensor when i read the first line. As your needing a HG done anyway, get that done then see about replacing any sensors.
3. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

   #3 1st December 2009, 20:14

   Its very strange. Its the first time its done it, and literally stayed at bout 4k revs, then higher lol
4. RustySkull Saxperience Post Whore Joined: Oct 2009 Basildon And Corringham, Essex Posts: 5179 MK1 Focus RS, Discovery TD5, Renault Trafic 2.0

   #4 1st December 2009, 20:17

   Idle Control Valve mate, mine did that I cleaned the Valve and it works fine now, just take it off and clean it with Carb Cleaner
5. Mochachino Saxperience Hardcore! Joined: Nov 2007 Guantanamo Bay Posts: 28700 oyster card

   #5 1st December 2009, 20:17

   Does sound like the temp sensor as they stay at a certain rpm. Its just when the Temp sensor thinks the engine is colder than it is, therefore shooting more fuel in as this is what they do when theyre cold, but becouse its shooting more fuel in its having to let more air in too so the idle control valve opens up giving you the high rev.
6. RustySkull Saxperience Post Whore Joined: Oct 2009 Basildon And Corringham, Essex Posts: 5179 MK1 Focus RS, Discovery TD5, Renault Trafic 2.0

   #6 1st December 2009, 20:29

   Quote:

   Originally Posted by db_sax Does sound like the temp sensor as they stay at a certain rpm. Its just when the Temp sensor thinks the engine is colder than it is, therefore shooting more fuel in as this is what they do when theyre cold, but becouse its shooting more fuel in its having to let more air in too so the idle control valve opens up giving you the high rev.

   Temp Sensor wouldn't take it to 4,000rmp, a sticky Idle Control Valve would mine often went to 3,000/4,000 or it'd rev to 2,000 then to 0 then 2,000 really fast until I drove or turned it off.
7. Mochachino Saxperience Hardcore! Joined: Nov 2007 Guantanamo Bay Posts: 28700 oyster card

   #7 1st December 2009, 20:31

   Quote:

   Originally Posted by db_sax Does sound like the temp sensor as they stay at a certain rpm. Its just when the Temp sensor thinks the engine is colder than it is, therefore shooting more fuel in as this is what they do when theyre cold, but becouse its shooting more fuel in its having to let more air in too so the idle control valve opens up giving you the high rev.

   Quote:

   Originally Posted by Bikekid450 Temp Sensor wouldn't take it to 4,000rmp, a sticky Idle Control Valve would mine often went to 3,000/4,000 or it'd rev to 2,000 then to 0 then 2,000 really fast until I drove or turned it off.

   A Temp Sensor would
   
   Also i said Stay at a certain RPM, you have about 64 different RPMs in ur description..
8. Mochachino Saxperience Hardcore! Joined: Nov 2007 Guantanamo Bay Posts: 28700 oyster card

   #8 1st December 2009, 20:34

   Quote:

   Originally Posted by SaxoAL Just pulled into my garage and revs stuck on at same as what it was when I pulled in. Then when I pressed throttle it went up more and stayed up, then after a couple of seconds went back down to normal. I had my cambelt done over the weekendan but all seems fine there I think. Engine and oil temp about normal. I know I'm. Goin to need a HG soon as I have a very slight leak I think. Could this be the prob or is it maybe ICV or temp sensor?

   Just rmembered the test to see if its the temp sensor. When its idling high at 4k, unplug the temp senor and see if the revs drop
9. RustySkull Saxperience Post Whore Joined: Oct 2009 Basildon And Corringham, Essex Posts: 5179 MK1 Focus RS, Discovery TD5, Renault Trafic 2.0

   #9 1st December 2009, 20:34

   Quote:

   Originally Posted by db_sax A Temp Sensor would Also i said Stay at a certain RPM, you have about 64 different RPMs in ur description..

   It could be the Temp Sensor, But a sticky Idle Control Valve also does the same.
   
   And yeh my car has a mind of its' own haha
10. Mochachino Saxperience Hardcore! Joined: Nov 2007 Guantanamo Bay Posts: 28700 oyster card

    #10 1st December 2009, 20:39

    Quote:

    Originally Posted by Bikekid450 It could be the Temp Sensor, But a sticky Idle Control Valve also does the same. And yeh my car has a mind of its' own haha

    ICV go at all sorts of random RPM's.
    
    I did a guide for cleaning and replacing the ICV a few years ago, have a search if you need it
11. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

    #11 1st December 2009, 21:32

    Sweet, thanks guys will check that out now.
12. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #12 2nd December 2009, 00:12

    Like Danny is saying, it does sound alot like the coolant temp sensor. Its the green one on the thermostat
13. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

    #13 2nd December 2009, 08:02

    Sweet. I'll order a new one today. Is it easy to get to Tom?
14. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #14 2nd December 2009, 08:05

    yer right where the bleed vavle is on the thermostat
15. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

    #15 2nd December 2009, 08:49

    thanks mate, I'll try and change that today. Last time I did one, on my old 1.4, it was only a tenner or so, so may aswell try it.
    
    Just noticed on my way in to work, the jolting juddering I get when driving only seems to be around 3k rpm and only when sitting at that rpm or when decelarting down to that rpm?
16. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #16 2nd December 2009, 08:52

    i paid £6.50 at euro car parts few months back. Dont forget to bleed the cooling system again
17. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

    #17 2nd December 2009, 10:16

    one of my suppliers just asked me if it is a green plug, or a green plug with yellow ring on it?
18. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #18 2nd December 2009, 10:19

    I thought they were green and blue? Im going to say green as thats what i bought
19. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

    #19 2nd December 2009, 10:22

    100% the ICV, mine did the same thing.
    Cleaned it and hey presto, all was good again.
20. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

    #20 2nd December 2009, 10:25

    I should say unless the engine is running at some super rich ratio (it won't) there is no way in hell the engine can rev to 4k+ at idle throttle opening, the ICV is holding the throttle open a touch which registers on the TPS as a part open throttle and as a result the ecu chucks the correct amount of fuel in to match the air. Thus the revs go up. If the throttle isn't open, the engine can't chuck that much fuel in to make it rev, it'll just bog down.

    1 user thanked this post: tyler1400
21. Walnaldinho L-plater Joined: Apr 2007 Posts: 36

    #21 17th September 2010, 17:52

    Mine has been doing this the last couple of weeks.
    
    Tends to be around 1500-2000rpm it get's stuck on. Drops again if I take my foot of the clutch (hit biting point).
    
    Do you guys suspect the ICV or temp sensor for this, or something else?