Idle Problem When Revved...

[DirtyFlare 0]

If my car is hot or not I still have the same problem.

 

The problem is when i blip the throtlle the revs will increase like they should but when I release the throttle pedal the revs will drastically decrese below the idle speed and then go up to the idle speed.

 

This happens all the time, the main problem is when the car is still cold and i come up to a junction and have to put the clutch in as i have to stop, normally resulting in the car stalling.

 

Can anyone give me an idea as to what could be casuing this?

 

Also when the revs go below the idle speed the water temp, oil pressure warning and stop lights come on untill the revs pick back up.

 

any help would be great

Edited December 1, 2006 by DirtyFlare

[mickie 3]

mine is totally the same at thew mo but its because i've put in a different camshaft, shims and lifters without setting them up right..

 

its tappy mine tho and im guessing its keeping some valves open causing it to stall

[j_turnell 137 3 Cars]

Try doing a search! Does your TPS click when you opperate the throttle by hand?

[pug_ham 244 3 Cars]

This is fairly normal procedure for this time of year when the electrical load is higher due to heaters etc being on.

 

Try a search like James suggests but really all you need to do is give the full intake system, AFM & throttle body a really good clean out with carb cleaner & set it up properly as mentioned in this post.

 

Graham.

[Guest srack]

also check for vacuum (air) leak.

i suggest to set the AFM to fit this time of the year ( we do it etc half a year over israel), along with the euro4 testing to make sure the CO is right.

setting the afm is easy, if you know what you are doing.

also - whats your idle rpm?

[DirtyFlare 0]

Try doing a search! Does your TPS click when you opperate the throttle by hand?

 

I did a search but couldn't find a suitable answer to my question. Also could some please tell me what the abriviation "TPS" stands for? Thanx

 

Try a search like James suggests but really all you need to do is give the full intake system, AFM & throttle body a really good clean out with carb cleaner & set it up properly as mentioned in this post.

 

Ok great, i will clean every thing and hope this helps also. the post is a great help thanx.

 

also check for vacuum (air) leak.

i suggest to set the AFM to fit this time of the year ( we do it etc half a year over israel), along with the euro4 testing to make sure the CO is right.

setting the afm is easy, if you know what you are doing.

also - whats your idle rpm?

 

My idle speed varies greatly. When cold it will sit at about 1,000 rpm when warm any where between 1 - 1.500 rpm.

[pug_ham 244 3 Cars]

Also could some please tell me what the abriviation "TPS" stands for? Thanx

Throttle position switch.

 

With the throttle closed you should get a closed circuit between pins 18 & 2, open circuit beween 18 & 2 or 18 & 3 with the throttle mid travel & closed circuit between 18 & 3 at fully open. (pin 18 is the middle pin of the three on the switch with pin 2 being the lowest & 3 top on the car).

 

Graham.

[jim21070 2]

I reckon it is pretty normal at this time of the year. I suffer it to a degree.

 

Got to agree with all of the preceeding.

 

This evening I took particular notice of how mine behaved.

 

Car starts normally from cold, idles at 1500 RPM (SAD Open).

 

Idles a bit jerkily with full electrical load on when SAD closes and before fully warmed up.

 

Pootling through town, fully warmed up, idles at 900 RPM fine.

 

Take it for a blast at 70 or so for a few miles, I come up to a roundabout and it nearly stalls before catching itself. Does the same again at the next roundabout. Pootle back through town, lots of start-stop, idles perfectly every time.

 

Arrive home, leave it idling with lights on. 900RPM solid all the time it takes me to start up the Xantia, wait for the suspension to rise and move it out of the way before tucking the 205 into its weekday sleeping quarters.

 

My conclusion: It does not like the ice-cold air it ingests whilst blasting along which cools the inlet tract right down, hence the near-stall when approaching a roundabout after a long, fast run. Pootling through town warms the inlet tract a bit and the idle behaviour returns to normal.

 

This is bourne out by the fact that I never have any sort of idle problems in warm weather.

 

What the inlet tract needs is a warm air feed in winter. I reckon if such a thing could be rigged a great deal of our cold weather problems would be resolved and the amount of mayonnaise we collect would be considerably reduced too.

 

Any thoughts? Mine is running the standard air filter and intake plumbing.

Edited December 3, 2006 by jim21070

[DirtyFlare 0]

Throttle position switch.

 

With the throttle closed you should get a closed circuit between pins 18 & 2, open circuit beween 18 & 2 or 18 & 3 with the throttle mid travel & closed circuit between 18 & 3 at fully open. (pin 18 is the middle pin of the three on the switch with pin 2 being the lowest & 3 top on the car).

 

Graham.

 

Where is the Throttle position switch located in a 1.6 gti engine bay?

 

Thanx for any help

[Richie-Van-GTi 72 2 Cars]

TPS is on the front of the throttle body, helkd on by 2 7mm bolts IIRC.

[scumbag 0]

Between the black air filter box and the afm unit, where the hoses join, there is a hole on the seal. Any chance this could cause my bouncy revs? Sunday I am going to clean out all the AFM, throttle body and all with carb cleaner. Hopefully this may help. I think I may try just taping the hole for a bit to see if there is any improvement!

[pug_ham 244 3 Cars]

Between the black air filter box and the afm unit, where the hoses join, there is a hole on the seal. Any chance this could cause my bouncy revs?

Personally I don't think so, anything before the AFM won't be the reason for your bouncy revs.

 

Graham.