Revving up to 2k to 3k on it's own! Help!

26th September 2011, 10:10

Hey everyone,

This is really starting to grind my gears! My Saxo is revving right up to between 2k and 3k rpm. It's ok when I first start it but as soon as I press the accelerator it shoots up! It does it randomly.

I've changed the Idle Control Valve for a shiny new one, my old one was covered in black sooty stuff. It seems to have made it worse and do it more often! I tried doing the ICV reset thing with turning the ignition on 2 clicks, 3 times then starting her.

Any advice would really be awesome! Would rather not take it to a garage cos they're getting expensive nowadays!

List of things to check / replace:

* Idle Control Valve - Replaced with new one, made problem worse... over revved more frequently
* Clean Throttle Body - Garage did this when I tried to get them to fix it
* Check Battery - Halfords checked and battery is on 75%
* Disconnect Battery for Reset - Did this for atleast 3 hours but the problem still happens
* Reset ICV by turning ignition on and off - Did this plenty of times but nothing changed apart from when I first fitted the new ICV
* Engine Coolant Temperature Sensor - Replaced this and the problem is still happening!
* Map Sensor
* Coil Pack
* Air Leak

26th September 2011, 10:42

it not misfiring? coilpack...

26th September 2011, 12:44

no its not misfiring. it starts up fine but as soon as i start driving the revs shoot up.

29th September 2011, 10:51

Update:

I've replaced the ICV and it seems to have made it worse... now I don't know if this is because the new one is cleaner or faulty. The old one was completely covered in some black sooty looking stuff. Might clean it up and refit it as I'm still having the same problem.

I've now started replacing the sensors... got an engine coolant temperature sensor coming soon. This seems to be mentioned a lot when this fault happens. If it's not that it could also be the map sensor.

29th September 2011, 10:52

check your battery just in case. When the battery loses amps and voltage, the car revs up to compensate through the alternator.

29th September 2011, 11:07

Quote:

Originally Posted by Manu

check your battery just in case. When the battery loses amps and voltage, the car revs up to compensate through the alternator.

oh really? i did not know that! Damn... could I have wasted money on these things? I'll get that done on my lunch break. I don't know how old the battery is, I haven't replaced it but only had it 6 months. I have noticed that when I have my music loud the car loses revs as if it's struggling. I only have factory speakers nothing fancy...

29th September 2011, 13:07

Halfrauds checked my battery for me and its fine and holding charge. Needs replacing at some point just cos its so old but its not effecting the problem at the mo.

29th September 2011, 13:12

if it's still working then good, you know it's not the problem. Try unplugging the battery overnight so you're sure you get a full reset then start again from there. I remember having the same problem on my previous 106, turned out to be the coilpack.

29th September 2011, 13:25

Quote:

Originally Posted by Manu

if it's still working then good, you know it's not the problem. Try unplugging the battery overnight so you're sure you get a full reset then start again from there. I remember having the same problem on my previous 106, turned out to be the coilpack.

I disconnected the battery the other night for a good 3-4 hours. The problem still persisted! I'm pulling my hair out! Is there a way of checking the coil pack?

29th September 2011, 16:24

Do you have an air leak? Way to test this is spray WD40/easy start round the inlet where it joins the head - if the revs rise, air is getting in.

29th September 2011, 16:55

Quote:

Originally Posted by Gandi699

Do you have an air leak? Way to test this is spray WD40/easy start round the inlet where it joins the head - if the revs rise, air is getting in.

Thanks Gandi, I'll do that tonight. I could have possibly knocked something when fitting the new ICV making the air leak worse... maybe thats why it does it more often. How can I find an air leak?

29th September 2011, 16:59

Check all the pipe work and around the seals from the inlet to the head. The WD40 will show up where the leak is if you test a part at a time

29th September 2011, 17:04

imo i don't think it would be the coilpack they usually play up when they get hot with the icv you would be best trying an original part from another saxo if u can get hold of one as I find aftermarket ones never quite work right so that could still be the problem, does sound like an air leak how the revs are shooting rite up though

29th September 2011, 17:16

It will most likely be the coolant temp sensor.

30th September 2011, 10:13

Update!
My Coolant Temp Sensor arrived yesterday but unfortunately was the wrong shape... =/

Although I did take the sensor out my car and it was covered in junk, so I cleaned it and put it back in... drove around for ages and it didnt over rev, thinking I fixed I went home and parked up. Couple hours later I went out again and the problem started happening again.

I'm going to the scrappy tomorrow and picking up sensors, ICVs, anything I can get my hands on that might help fix it.

2nd October 2011, 10:52

mine does this allways 2 and 3k i usually take the battery lead of for few hours and its fine

2nd October 2011, 11:15

mine used to do that soon as you put clutch in it drops ?

3rd October 2011, 11:15

Update!
Went to the scrappy on Saturday and picked up a handful of sensors. I replaced the engine coolant temperature sensor and it seemed to have fixed the problem. At first it was over revving but my mate fiddled with the throttle cable and it stopped. I think the throttle cable is getting stuck some how.

It hadnt revved up since then until this morning. Going to have a look at the throttle cable tonight.

3rd October 2011, 19:13

If it's not that mate i would try disconnecting the battery, I had the same problem and it was that!

3rd October 2011, 19:39

sometimes if its an ebay icv they fuck up, i tried 3 of them from ebay and sending them back always rubbish idling so i went to citroen and bought the oem one brand new and the problem dissapeared altogether

4th October 2011, 13:33

Quote:

Originally Posted by kyle4256

sometimes if its an ebay icv they fuck up, i tried 3 of them from ebay and sending them back always rubbish idling so i went to citroen and bought the oem one brand new and the problem dissapeared altogether

How much did it cost from Citroen though?

6th October 2011, 00:53

Hi mate just wondered if you've fixed yours yet mines drivin me up the wall pretty much given up fixing it tbh ive tried:
coilpack
temp sensor
crank sensor
icv
map sensor
throttle position sensor
checked for air leaks
cleaned tb

only things I have left are lambda sensors, ecu, battery and alternator as far as im aware!

6th October 2011, 14:32

check the breather pipes, or check for air leaks in the manifold. you can get leak detection spray for this.

6th October 2011, 20:28

Christine.

You need to disconnect the battery after replacing the ICV, the ecu needs to reset.

Other than that, if you want to pop it over i dont mind having a look.

11th October 2011, 13:53

Still not fixed it yet and I did disconnect the battery for a good few hours and that didnt seem to do anything. maybe that was before the new ICV... hmm... I'll try that again later.

When it over revved my mate moved the throttle cable about and it stopped it. Could it be the throttle cable?