Idling rough!

[allaboutthevtr]

Hello i was wondering if any one can help me!
Ive Just recently brought a Saxo VTR 2002 model. Now from cold the car starts up fine, no problems atall with idling! But if i go for a fairly long drive, get it all hot etc .. When i come to stop and switch the engine off, if i turn it back on again, its starts to idle dropping bellow 1000rpm then jumping back up and back down etc.
Its been fitted with a pipercross induction, but where you have the breather hose coming off the crack case to the actuall air filter. They have bodged the hose on to the filter area. So ive gone and purchased a breather filter and blocked the hole up, ensuring i dont have an air leak. But the problem still happends, with the idling when hot! Just wondering if any one has any ideas, id be greatfull :y:
Cheers

[JamesR]

Any pictures of your engine? so i can see whats happening?

[Mochachino]

Coolant temp sensor the blue one :y:

Engine thinks its cold when you switch it back on when its actually hot, therefore shoots more fuel into the engine causing it to idle high to compensate for the extra fuel being added.

MAP, ICV and LamBda can also play a part in this.

[allaboutthevtr]

Unfortuantly Saxo_vtr123 i carnt upload any pictures, as im at work :) But thank you for trying to help me :)
db_sax - Cheers for the advise mate, i mean the temp sensor would be the best option and the cheepest out of the other possibilities. So i shall get on the old buzza to citreon and get the engine temp sensor (blue one) Give that a go :D. I was gona but some fuel additive, through the sytem cleaning the injectors etc, thought that would help or sumin, but ill try the temp sensor first. cheers :D

[allaboutthevtr]

Oh yeah i forgot to mention, i have no warning lights on my dash! Could this still be a temp sensor? As i was gona get it plugged in today and see if it brought any thing up, but wernt to sure if it would as its not registering no faults!
Cheers

[Mochachino]

Fuel additive doesn't do much anyway, many people say it can damage the injectors. Try a tank of V power to clean your fueling system.

Dodgy idles can be a pain on saxo's. Might be worth testing a few sensors off other VTR's that you know work, or it can get a bit expensive, or a diagnostics at a garage for around £40.

[Mochachino]

Oh yeah i forgot to mention, i have no warning lights on my dash! Could this still be a temp sensor? As i was gona get it plugged in today and see if it brought any thing up, but wernt to sure if it would as its not registering no faults!
Cheers

Not sure about Mk2's as they're ECU's are more sophisticated than a mk1. Irc they only show the warning on the dash for more critical faults or when its in Limp mode. A diagnostics will show up any problems and has a fault history as well, so shows any problems that may have occurred in the past.

[Liam_]

Sounds like it may be the ICV or coolant temp sensor to me. Try removing the throttle body and then the ICV - give them both a clean and see how it goes.

Failing that, a new coolant temp sensor (blue plastic which screws into the top of the thermostat housing) isn't much.

[allaboutthevtr]

Ohryt i see, whats V power then?
Yeah you know, its a right pain! Well i mean ill get it plugged in, see if it brings anything up! If it dont ill still go ahead and replace the temp sensor, as i can get parts dirty cheep for cars as i work for volkswagen :0) So its not so much the cost of it, just how long it takes to correct the issue. Does that sound like sumin you would do, from this stage?
Many thanks

[Mochachino]

Sounds like it may be the ICV or coolant temp sensor to me. Try removing the throttle body and then the ICV - give them both a clean and see how it goes.

Failing that, a new coolant temp sensor (blue plastic which screws into the top of the thermostat housing) isn't much.


Guide to Cleaning ICV here:

http://www.saxperience.com/forum/showthread.php?t=174710

[Mochachino]

Ohryt i see, whats V power then?
Yeah you know, its a right pain! Well i mean ill get it plugged in, see if it brings anything up! If it dont ill still go ahead and replace the temp sensor, as i can get parts dirty cheep for cars as i work for volkswagen :0) So its not so much the cost of it, just how long it takes to correct the issue. Does that sound like sumin you would do, from this stage?
Many thanks

Yeh i went along this route on my old engine, cleaned ICV no difference, replaced it, replaced the MAP sensor, re-wired the coolant temp sensor, new lambda and loom. Diagnostics brought nothing up. Then the whole engine died with LOADS of problems so bought a new one.

V-power is Shell fuel! Has cleaning additives in :y:

[Liam_]

Guide to Cleaning ICV here:

http://www.saxperience.com/forum/showthread.php?t=174710

Aye, the ICV is in the same place on the 98bhp VTRs. The throttle body is slightly different though as it slots into a plastic sleeve on the inlet manifold.

Remove airbox, remove the screws facing into the inlet manifold for the TB, unclip the throttle cable and it will slide out. Worth giving it a clean as the back of the TB gets well gunked up if the car uses the standard oil breathers. :wacko:

[allaboutthevtr]

Allryt guys cheers for all your help db_sax and LeeumH
Many thanks, ill give it a go!
:D