Rough Idle?

[mercury 0]

Hi guys,

 

did a search on issues with rough idle (needle bouncing up and down sometimes)

 

could this be caused by dirty throttle bodies? I read on a previous post that he just cleaned it with carb cleaner and it helped. Where there any other areas i should clean or look at regarding rough idle?

 

car is a 1.9 series 1 205 gti.

 

Cheers,

Merc

[Ethos 0]

Hi mate,

 

Clean throttle bodie, clean idle control screw, clean breathers, check for any air leaks, could always re-track the afm etc...

 

Lots to do for the idle!

[mercury 0]

Hi Ethos,

 

thanks for that. I will start witht he throttle body and work my way to the list.

 

Will i have to remove the throttle body or just spray some carb cleaner/wd40 srtaight on there?

 

Cheers,

Merc

[Ethos 0]

To do it properly remove it as you'll need access to both sides properly. Use carb cleaner as well....

 

[mercury 0]

Hi Ehtos,

 

do you know if there is a writeup anywhere ont he web on how to remove it?

 

Is it a fairly straighr forward job with existing bolts and wires being re-used when putting it all back together?

 

Cheers,

Merc

[Ethos 0]

Trying to remember, I think you just have to unplug the TPS, remove a few bolts and it pops off. You might have to take the throttle cable off too, but you might be able to get away with leaving that on if you clean it over the engine.

 

A post from pugtorque a while ago;

 

"Give the whole of the intake including the throttle body, AFM, SAD & all breather hoses a thorough cleaning with some carb or brake cleaner & check them for condition.

 

Even take the throttle body off to clean both sides of the throttle plate, remove the idle speed adjusting screw & use some cotton buds to clean the bypass in the throttle body. Whilst this screw is out, clean that until it shines.

 

Once ts all back together get the car hot so the cooling fan has cut in & if necessary adjustteh idle speed to aropund 1000rpm instead of 900rpm to help things out.

 

Graham. "

[mercury 0]

Trying to remember, I think you just have to unplug the TPS, remove a few bolts and it pops off. You might have to take the throttle cable off too, but you might be able to get away with leaving that on if you clean it over the engine.

 

A post from pugtorque a while ago;

 

"Give the whole of the intake including the throttle body, AFM, SAD & all breather hoses a thorough cleaning with some carb or brake cleaner & check them for condition.

 

Even take the throttle body off to clean both sides of the throttle plate, remove the idle speed adjusting screw & use some cotton buds to clean the bypass in the throttle body. Whilst this screw is out, clean that until it shines.

 

Once ts all back together get the car hot so the cooling fan has cut in & if necessary adjustteh idle speed to aropund 1000rpm instead of 900rpm to help things out.

 

Graham. "

 

ok so heres a pic of it,

 

is it ok to spray right in that hole that closes and opens when u pull on the throttle cable?

 

 

 

Also what is the TPS and the SAD?

 

the AFM is this right? (pic below)

Edited August 15, 2008 by mercury

[mercury 0]

Also is this the idle screw you recommend spraying with carb cleaner?

[mercury 0]

oh and here are some more pictures to help illustrate.

 

 

I removed the hoses, battery etc

 

also how do you re-track the AFM? would you need to send it to a specialist or can you DIY?

 

Cheers,

Merc

Edited August 15, 2008 by mercury

[Guest Hogan's Pug]

I am also interested to know if that screw in pic is the idle screw?

[welshpug 1,622]

Also is this the idle screw you recommend spraying with carb cleaner?

 

nope, the large brass one to the right of it.

 

I am also interested to know if that screw in pic is the idle screw?

 

as above

[Rock Lobster 28]

yeah the idle screw is the large brass one on the throttle body, the TPS is the throttle position sensor which is also attached to the side of the throttle body, and last but not least is the Supplementary Air device, the basically allows more air into the engine but by passes the Throttle body, its located just below the distributer (ish) quite easy to spot.

 

I think there is an excellent article somewhere on the main site that tells you all about the AFM etc and what they do, very useful. Hope this helps a little and doesn't just seem like rambling!

 

Huw.

[Guest Hogan's Pug]

ahh i see thanks. also can i ask on the inlet manifold where the oil filer thing sits there is a little bolt that holds it on, if this bolt is out you can hear the inlet sucking air in, and my car runs (kinda badly), but when i screw the bolt in it stalls. any ideas?

[pug_ham 240 3 Cars]

Engine bay layout

 

That bolt on the inlet manifold needs to be there for it to run properly.

 

Refit that bolt & start again from scratch with all the settings until you get a decent steady idle, it is possible with a little work & a nice clean throttle body.

 

Graham.

[Guest Hogan's Pug]

yea i thought it did, i think the person had taken it out so it ran at idle when he sold it.

[Rock Lobster 28]

thats sly!

 

I'm curious what is meant by re-tracking the afm? is there info on this site about it? haven't got time to do a search right now but will be back on later.

[leon 1.9 0]

I SHOULD say 'use the search' but as sometime search results seem rather random on here, look at this page:

http://frwilk.com/944dme/afm.htm

 

Its for Porsche 944 AFMs, but 205 gti's use the same type. Retracking gives the potentiometer in Air Flow Meter a good contact as most are worn inside nowadays.

 

The main site also has more info on it.

[shalmaneser 26]

I SHOULD say 'use the search' but as sometime search results seem rather random on here, look at this page:

http://frwilk.com/944dme/afm.htm

 

Its for Porsche 944 AFMs, but 205 gti's use the same type. Retracking gives the potentiometer in Air Flow Meter a good contact as most are worn inside nowadays.

 

The main site also has more info on it.

 

great link!

 

cheers

[leon 1.9 0]

Can't remember who originally put the link up, but it is a great help! I'm not promising all the figures are the same, but the figures are around in different threads/ or member's heads.

[Rock Lobster 28]

brilliant, thanks mate!

[Guest Hogan's Pug]

yea haynes manual is really good, explanes idle adjustment, throttle bodie and afm really well. worth gettin one i think!

[RINRIN 1]

Yesterday I start to clean the throttle at 1 PM. I start dismounting the parts around throttle. In the beginning the I took a pic

 

After dismantling I start cleaning the throttle

Before

 

After

[RINRIN 1]

and I start to assamble everything back. Then the problem starts with the oil hose under the oil catcher.

I thought I can change it (also I need to) then I go and bought one. When I came back I recognised that It is not suitable and I changed the way of the hose. When I am doing this I need to pull alot of wiring looms. Also the hoses after AFM looks air leaking and I removed it and renewed the pipes for leaking.

 

At the end I managed to do it and start the engine.

The idle was at 2000rpm and I start to turn the idle screw and It came to end at 1600rpm. I couldnt make it lover.

And I start to turn the Throttle screw to change the position of throttle but at the end I get 1400rpm.

Also when I get in the car I saw that oil pressure switch is not functioning any more.

Please help how can I lower the rpm to 1000 (what is the problem) and where is the oil pressure sensor ( what could be the problem)

[RINRIN 1]

Any help?

[RINRIN 1]

Ok, I adjusted the TPS. First I dismantle it and check the resistances and both is OK and I put it back and made the "cit" adjustment I was doing this yesterday night so I couldnt go for a run but today I will adjust the idle screw. I hope at the end I will have a steady idle with full loads.