Idle issue. Anyone got any ideas, because i'm all out!

[jon_r]

OK, so start the car and it idles spot on.

Touch the throttle, drive away etc then come to a junction, or anything and the car idles at 2000 rpm (maybe more). Occasionally it settles at 1500rpm and then 'hunts' and will rev between 1500 and 2000. If you then stab the throttle the idle settles to where it should do.

To try and cure this i've replaced:

Throttle body. No change.
Throttle cable. No change
Replacement idle valve which i was assured was in 100% perfect working order. This made the revs sat at 2500 rpm and not 2000 and it spluttered at low revs!

I've had the whole inlet apart to try and find a missing seal or something, it all looked fine.

Could it be lambda, it's all i've got left to try?!

 

[jamesd1263]

Might be an air leak somewhere, try seating the inlet again! May be that

 

[jon_r]

I've already tried that a couple of time, no luck so far.

 

[jicholasnackson]

Do you ever have it sometimes when you are parking the car might randomly stall?

And sometimes when slowing down to lights if you dip the clutch early, the car will like splutter and then stall?

 

[jon_r]

No it never stalls, or splutters. Just idles at 2000rpm

 

[ciaran1380]

spray some gt85 or wd40 around the joints and see if the idle drops

 

[Jonathan]

Next time it is idling high, don't touch anything, pop the bonnet and push the throttle body against its end stop using the black plastic disc the cable attaches to, to see of it was on the end stop or not quite. If its hard on the end stop and the revs stay high its definitely not the butterfly sticking (on the 'new' TB).

 

[jon_r]

See the original throttle body did that so that was the first thing I replaced. I've not checked if the new one does it because it came straight of a car that was running fine, but I can check.

 

[Russ_16v]

You got time to drive to Wiltshire? Come see me, we can swap bits back to back off mine and il find out what it is mate, im still saying icv or tb dude, takes a while to get it all set up right and working lol


my guide in the guides section will sort out the tb sticking, and id resort to buying a new genuine icv.

Or if you cant come and see me, send me your tb, il do the guide thing and il send my icv for you to try

 

[jon_r]

Russ, i'll pm you.

I've tried refurbing my original tb and the spring feels really tight, the recoil on the butterfly could snap your finger off so i'm convinced it's not that!

 

[Rob]

Take some proper time cleaning it with some proper lubricant (not wd40) and see how you get one.

My ph1 had the exact same thing and what fixed it was cleaning the life out of the throttle body. Like mentally. Took it off the car, toothbrush, wd40 and silicone spray.

Literally filled it up with wd40. Scrubbed any moving parts with the tooth brush, repeated this many times.

Then silicone sprayed the whole thing, several times.

Also, is your throttle cable route good and true? If it's not as smooth as it could be, it might be catching slightly.

Also also, your throttle cable isn't catching where it goes through the bulkhead is it? They can frey there so not return to fully closed? Operate the cable by hand and check.

 

[jon_r]

Rob, a brand new Renault cable was fitted yesterday and I made the route as smooth as possible, there are no sharp kinks etc. The old one was almost new as well.

I've done all of that with the tb already, but i'll try again tonight. Used a whole can of carb cleaner on it!

 

[Rob]

Cleaned it up with carb cleaner, great, but did you lubricate it?

Only other thing is, look inside the TB for signs of catching?

If it's heating up then catching on the inside, there should be some markings. A whole lot of balls and some wet and dry could sort it out

 

[Revels]

Mine does this too. But now nudging the throttle doesn't make it come back down like it should.

I need to clean the tb (apparently) so that's a job for Si one weekend TBH.

 

[Budgie]

My bet is the throttle body too.

I had to just use a bit of wet and dry around the inside to make it 'close' properly.

 

[Rob]

You have to be careful how much you use though because you could make it not seal properly, bit of a b*****d really.

 

[Chip-mk1]

When its doing it, stick a pair of molegrips on the pipe to the ICV or crush it/ bend it with your hands, that way you know if the air is getting past the ICV or not to rule that one out.

Unplug the brake servo line and block that off as well.

Just work through it systematically trying to rule out everything one by one.

 

[jon_r]

Will do. I'll try later if I get any time.

I'm all for cleaning the throttle body (again), but I find it hard to believe both have exactly the same problem - especially when the second one came from a car that was running perfectly.

 

[The Dominator]

Have had the same issue with mine for 4 months tryed everything- Its now being looked at in the garage

Replaced everything possible, will let you no the outcome when it is sorted

 

[jon_r]

Please do!

 

[jon_r]

Ok, engine started, open throttle, revs stuck at 2k.

Pulled off the brake vac pipe and revs rose. Put back on and it settled back to 2k.
Unplugged ICV and nothing happened?
Next I pulled out the sensor at far end of inlet plenum (not sure what this one is? - it was quite loose!) revs rose, then fell, then it spluttered then stalled.

Next I tried the tb described as 100% fine, except it would appear it isn't:

http://i207.photobucket.com/albums/bb251/wrx_king/mk1-172/da30c69c.mp4

Im aware engine sounds noisy, the car is in a really, really enclosed space and I couldn't be arsed to push it out!

 

[Chip-mk1]

Did you try restricting the ICV pipe?

If ICV isnt shutting properly then disconnecting it wont stop flow, but restricting that pipe will.

 

[jon_r]

Nope, I gave up on everything else once I found the tb doing that.

Ill try again tomorrow on the ICV. I know the car ran Without a pipe on the ICV though.

 

[Chip-mk1]

no pipe isnt restrictive though

 

[Russ_16v]

Mine does this too. But now nudging the throttle doesn't make it come back down like it should.

I need to clean the tb (apparently) so that's a job for Si one weekend TBH.

b****cks mate im so sorry,il dig that spare one out and send it for you to try too

 

[jon_r]

no pipe isnt restrictive though

Gotcha. I'll try that tomorrow.

 

[jon_r]

Right I've spent the last hour + cleaning the original throttle body up. It's virtually like new now so if this doesn't work the issue is elsewhere. It virtually snaps your fingers off on closing!!

Currently soaking in grease spray overnight.

 

[Russ_16v]

Spot on mate, making sure its properly lubed is the key - though im still leaning towards icv lol

 

[jon_r]

But in the video above I can twist the throttle body shut and it cuts the revs. Would the ICV cause that?

 

[Russ_16v]

How did i miss that vid?! Full r****d lol

yeah thats the tb sticking mate, as you hold the cable holder it closes the butterfly up - another issue iv found is the butterfly spindle wears, so if you grab the butterfly you can actually move it side to side, and it sticks due to the butterfly moving on the spindle and catching on the edges of the tb

if that doesnt work dude, post it to me and il have a look at it and try it

 

[Jonff]

Mine was doing exactly the same thing in the video. I tried cleaning it following Russ' guide several times to no avail. In the end I just dismantled it and cleaned it that way instead then soaked all the moving parts in oil to lubricate it. Improved things a hell of a lot but I do occasionally get the revs sticking still. Only thing I can think is the spring has become weak and might be the same problem you're experiencing?

 

[Chip-mk1]

But in the video above I can twist the throttle body shut and it cuts the revs. Would the ICV cause that?

The ecu adjusts the iscv duty cycle to match what's needed so a sudden change to even less airflow from the itb can still cause a dip but I have no sound to listen to the video to say if that's likely or not in your case.

After changing throttle body did you take the battery off and leave the ecu to reset?

 

[jon_r]

No, left that all hooked up. I've gone out and disconnected it all before work, so it'll all be reset this evening when I'm home.

Mine was doing exactly the same thing in the video. I tried cleaning it following Russ' guide several times to no avail. In the end I just dismantled it and cleaned it that way instead then soaked all the moving parts in oil to lubricate it. Improved things a hell of a lot but I do occasionally get the revs sticking still. Only thing I can think is the spring has become weak and might be the same problem you're experiencing?

There is about 1mm of side to side movement on the spindle on this tb, so i'm wondering if this is causing some of the issue. I guess i'll find out if it's worked later.

The spring feels pretty strong to me, it really snaps shut, but it's hard to tell how worn it is without compairing with a new one.

 

[Dan519]

There is about 1mm of side to side movement on the spindle on this tb, so i'm wondering if this is causing some of the issue. I guess i'll find out if it's worked later.

absolutely it will!! you should be able to tighten that up by tapping the circlip a little further on (the one beneath the TPS on the end of the shaft)

The ICV on these are a little vague in their self centering, they take about 3 seconds to calibrate each time the car is started and if they don't get a chance to zero they can wander. If you turn the ignition on and off a few times and leave it on for 10-15 seconds at a time this should help is find its correct zero point (although I'm very dubious that it's even an issue at all for you now)

 

[jon_r]

Dan, I'll try and tighten the circlip up as much as I can later. I assume a small socket over the end of the shaft will sort it?

When I put the new ICV on I did turn the ignition on and off a few times and went for a 10 minute run out. It idles perfectly when it's not faffing about at 2k! I have a feeling i've got 2 good ICV's and it's been the TB's all along. Keen to get home and try it now!

Cheers

 

[Dan519]

yes, small socket and give it a tap, just make sure the spindle is moving freely and smooth afterwards (ie not over tightened)

I'm sure you're right and it's just the TB all along

 

[Chrisgti6]

My brother currently has a 306 Cabrio with a very silmilar problem. we've traced that to an air leak on the inlet. I started stripping it down on Saturday after trying the ICV etc and found the o-ring on the bottom of one of the injectors was split and missing a piece.

I found it was definate a leak by stalling the car and listening for it drawing air in. With the car running and the pipe off the ICV I blocked the end of the ICV off, the car stalled and at this point a hissing noise could be heard from the center of the inlet manifold indicating an air leak. The rest was just locating where the leak was and after pulling the fuel rail off, I found it.

 

[davo172]

Could it be Lambda sensor , cant see Throttle body from what your saying and have done .

 

[Chip-mk1]

Could it be Lambda sensor , cant see Throttle body from what your saying and have done .

I cant see how a lambda sensor could cause this particular issue really TBH

 

[Jonff]

There is about 1mm of side to side movement on the spindle on this tb, so i'm wondering if this is causing some of the issue. I guess i'll find out if it's worked later.

The spring feels pretty strong to me, it really snaps shut, but it's hard to tell how worn it is without compairing with a new one.

The movement in the spindle, is that while the little torx screws in the centre of the spindle are in place and tight? Mine doesn't move until I undo those.

Also something else I tried was taking the butterfly out and flipping it around and putting it in the opposite way (if you get what I mean?) instantly it felt much better while opening the throttle body by hand where as previously it seemed to be catching slightly.