I Have A Problem, And I'm Unsure Of It's Solution...

[chocolate_o_brian 0]

I'll try keep this simple as it's a bit long winded.

 

Basically on cold morning like we've had recently, about 6.30 I go outside to start the car up. It has a new starter motor so fires up first time nice and quickly. I can then do one of 2 things.

 

First, I would leave it to idle itself. Recently this has resulted in either the car dropping to low revs and stalling (with battery light on) or trying to idle at 500-600rpm, which sounds awful and as though the cars in pain.

 

Second, start the car as above, but immediatley sit the car at 1500rpm or so with foot on throttle holding it there. This for about 20-30 seconds sorts the problem out of the car stalling at it then sits at about 800-900rpm after throttle is released. But if I say rev the car gently to 2000rpm it misfires terribly, making a ber-ber-ber sound noise which does vibrate the car a little.

 

It's worse when cold and awful when frosty. When the weather is warmish like the recent summer/autum weather, from cold the car wasn't too bad.

 

I'd love for someone to tell me what the problem is? I've thought of fueling for the misfire, blocked fuel filter, erm air leak, low battery charge (light comes on intermitantly when cold). I have a feeling the fueling is out slightly, as when setting of the car is jumpy and bogs down in 1st gear. But I am sure the horrible lumpyness and gastly misfire/stall/low idle is something else.

 

Any advice is appreciated, as I'm on a tight budget currently.

 

Thanks

 

Andy

[DrSarty 90 1 Cars]

I know this doesn't exactly answer your question technically - as the problem could be your SAD (supplementary air device), I(A)CV (idle (air) control valve, or you may have a breather hose off or split which is messing up your idle mixures - but no cars should be started up in the morning, whatever the weather and in particular in the cold, and left to run/warm up.

 

This is the second thread I've seen recently where the owner has said they do this, and whilst I do appreciate it's their car to do with as they please, this action is actually bad news for many components in the engine, including the exhaust system.

 

My old man always told me to drive the car straight away, taking it no higher than 3,000rpm until you get a temp reading on the gauge.

 

Sorry to not try and answer technically, but if you change your habit which is actually bad for the car, then maybe it'll not only clear the problem but increase the reliablity of your engine and create less problems (read: expense) in the future.

 

Just a thought.

Edited October 30, 2008 by DrSarty

[jackherer 543]

My old man always told me to drive the car straight away, taking it no higher than 3,000rpm until you get a temp reading on the gauge.

 

Thats basically what the 205 handbook says too.

[chocolate_o_brian 0]

I know this doesn't exactly answer your question technically - as the problem could be your SAD (supplementary air device), I(A)CV (idle (air) control valve, or you may have a breather hose off or split which is messing up your idle mixures - but no cars should be started up in the morning, whatever the weather and in particular in the cold, and left to run/warm up.

 

This is the second thread I've seen recently where the owner has said they do this, and whilst I do appreciate it's their car to do with as they please, this action is actually bad news for many components in the engine, including the exhaust system.

 

My old man always told me to drive the car straight away, taking it no higher than 3,000rpm until you get a temp reading on the gauge.

 

Sorry to not try and answer technically, but if you change your habit which is actually bad for the car, then maybe it'll not only clear the problem but increase the reliablity of your engine and create less problems (read: expense) in the future.

 

Just a thought.

 

No, totally understand what your saying. I think I was misunderstood. Recently, as in the last week or so, most mornings it's been frosty, so I've had to demist the car, which meant leaving it running for a couple of mins while the fans were on full whack. Usually (and with my old Impreza Turbo too), I would start the car, give it 20secs for the oil to rotate and lubricate the engine, and then move off.

 

The problem has increased as the weather has deteriorated basically. And it's worrying as the car sounds like a bag of spanners when I start it up. Oil level etc. is fine, so I'm hoping its a similar trait to the my97-98 Scoobs (mine was a my99 thus different engine layout and ECU) where they have a little piston slap, as the car quietens down when warm.

 

The issue is its so lumpy and jolty when I first start it up and move off straight away. It's almost impossible to get a biting point on the clutch as the revs keep dropping when reversing or moving out of a parking spot. Can you see what I mean?

 

Sorry if I caused confusion. To re-itterate the car only gets left runnign when cold if I have to de-ice/mist it and need the fans on.

[chocolate_o_brian 0]

No, totally understand what your saying. I think I was misunderstood. Recently, as in the last week or so, most mornings it's been frosty, so I've had to demist the car, which meant leaving it running for a couple of mins while the fans were on full whack. Usually (and with my old Impreza Turbo too), I would start the car, give it 20secs for the oil to rotate and lubricate the engine, and then move off.

 

The problem has increased as the weather has deteriorated basically. And it's worrying as the car sounds like a bag of spanners when I start it up. Oil level etc. is fine, so I'm hoping its a similar trait to the my97-98 Scoobs (mine was a my99 thus different engine layout and ECU) where they have a little piston slap, as the car quietens down when warm.

 

The issue is its so lumpy and jolty when I first start it up and move off straight away. It's almost impossible to get a biting point on the clutch as the revs keep dropping when reversing or moving out of a parking spot. Can you see what I mean?

 

Sorry if I caused confusion. To re-itterate the car only gets left runnign when cold if I have to de-ice/mist it and need the fans on.

 

I've pm'ed my mate who's clued up more so than me and has one of these for a track car. He does think it's the SAD, as the issues are when cold. Just curious if this is also causing the bunnyhop effect when travelling at uber low speed in traffic? Not pleasureable to drive. May also check the fuel filter too.

[GLPoomobile 958]

Sounds like a possible collection of poor settings on various components, compounding to make for poor running. Jerkiness at low speed (kangarooing) is very common and has tarred the 205 GTI since they early days, just like it's reputation for hedge chasing. It can be made better (some people, like Jackherer will say it can be cured, but I'm not convinced, unless you replace the archaic Jetronic management), but it can bit of a complicated affair, checking and adjusting quite a few things to get everything spot on. But the fact that you say the kangarooing is quite bad certainly leads me to believe you have some problems which are then showing up even more with the cold weather.

 

My initial impression of the cold start up would be a dodgy SAD, as Dr Sarty said. Possibly not opening up enough. The ECU Temp sensor will be telling the ECU that the engine is very cold, and so it will provide extra fuel, which the SAD should then compensate for by opening up to allow more air in (like a choke basically), which in turn will help the engine maintain a higher idle as it warms up.

 

The misfire could be a number of things relating to fuelling or ignition, so that's as far as my advice goes as I start to get out of my depth then

[richsmells 2]

Provided the car doesn't pink under load, and your sad is working, dialing in a bit of advance can help with sorting out dodgy idle. This will also raise the idle speed, so you will need to adjust this with the brass idle screw (which should be nice and clean). The misfire could be down to damp ignition components. Certainly mine did something very similar, and on REALLY cold mornings still does but after a decent setup and adding a bit more advance it's fine.

Edited October 31, 2008 by richsmells

[chocolate_o_brian 0]

Sounds like a possible collection of poor settings on various components, compounding to make for poor running. Jerkiness at low speed (kangarooing) is very common and has tarred the 205 GTI since they early days, just like it's reputation for hedge chasing. It can be made better (some people, like Jackherer will say it can be cured, but I'm not convinced, unless you replace the archaic Jetronic management), but it can bit of a complicated affair, checking and adjusting quite a few things to get everything spot on. But the fact that you say the kangarooing is quite bad certainly leads me to believe you have some problems which are then showing up even more with the cold weather.

 

My initial impression of the cold start up would be a dodgy SAD, as Dr Sarty said. Possibly not opening up enough. The ECU Temp sensor will be telling the ECU that the engine is very cold, and so it will provide extra fuel, which the SAD should then compensate for by opening up to allow more air in (like a choke basically), which in turn will help the engine maintain a higher idle as it warms up.

 

The misfire could be a number of things relating to fuelling or ignition, so that's as far as my advice goes as I start to get out of my depth then

Hmm... see what your saying. Appreciate the input.

 

So definitely will check the SAD, check all hoses for air leaks/cracks, and I should really go to a respectable garage and have the fueling mixture checked. I remember the fueling was very lean at M.O.T. time and failed on this. Maybe needs another tweak from a mechanics ear. From what you've said re. the SAD, the idle is very low when cold, so presume this needs checking, as the extra fuel being inserted isnt being met with enough air. Is that the basic jist of what you mean? If so, could this be over fueling when cold causing misfire? Or am I jumping the gun?

[richsmells 2]

Sounds feasible, but the only problems i've had with a SAD is that they close too early, causing the engine to "hunt" and stall before it is sufficiently warm. Like I said, provided everything else is okay and you have no leaks, adjust the ignition advance a tiny bit at a time. This cured the low idle problems on mine.

 

Check your ecu temp sensor and replace if necessary. This controls the cold start fuel enrichment.

 

Also your throttle position switch should audibly click when you open the butterfly from the idle position, this tells the ECU when the car is idling, part throttle or full throttle. Possibly not at fault but worth checking if you want to eliminate all possibilities.

Edited October 31, 2008 by richsmells