205 developed a rough idle...ne1 know how to fix?

205 developed a rough idle...ne1 know how to fix?

Author
Discussion

Uberloin

Original Poster:

39 posts

199 months

Thursday 15th May 2008
quotequote all
Hi,

I have recently checked and adjusted the valve clearances and spark plug gaps on my 205 1.1

Since then the car seems to accelerate a little more crisply at higher revs but is a bit rough and stuttery from idle where it wasn't before.

The valve clearance checking and adjustment was carried out by a competent amateur mechanic (he services his own cars and they are all longstanding high milers)

Last time I checked the spark plugs, i made no attempt to adjust the clearance between the electrodes; I was just checking their colour, which was fine. This time round the colour remained fine, however, he adjusted the spark plugs to the compromise between the two sets that were shown in the haynes manual as the spark plugs used weren't covered. He said as it was due for a service in a month they would (and should)be replaced.

I have noticed that the haynes manual attributes such problems to a number of things. I told him and he says the carb probably needs adjusting to compensates for the altered running of the engine. I'm really not so sure, so I thought I'd seek out a second opinion.

Bear in mind this engine has 146200 miles on it, but has been well serviced and had engine oil and filter changed at the appropriate times. Any ideas what to do?

shalmaneser

6,046 posts

202 months

Friday 16th May 2008
quotequote all
cleaning the carb is the first step to make. After that air filter. Only then start turning screws.

odyssey2200

18,650 posts

216 months

Friday 16th May 2008
quotequote all
Normally valve clearance settings have a few thou tollerance.
Did you do them to the tighter of the tollerance?

Uberloin

Original Poster:

39 posts

199 months

Saturday 17th May 2008
quotequote all
Well I don't know how you would negotiate between tolerances in this instance. We used feeler gauges. He did comment at how two of the valves were very hard to get right - i.e. a tiny turner clockwise and it was stiff, and a tiny turn counter-clockwise and it was quite loose...

Anyhow, we did it when the car was still slightly warm, so I redid it myself with it cold (left overnight) and the low end stuttering has stopped but it has started making a rapid ticking noise. I think one of them must be loose and is tapping?

I'm pissed off because I did it diligently and clearly incorrectly. :-(


Uberloin

Original Poster:

39 posts

199 months

Saturday 17th May 2008
quotequote all
Just another thought...

From what i've been reading this lack of middle ground on those two screws could be the cause of the problem - two worn adjusters. Still it was better before we buggered it up so :@

Uberloin

Original Poster:

39 posts

199 months

Saturday 17th May 2008
quotequote all
Ok i've redone it all - i'd used metric rather than imperial - no wander they were tapping. anyhow, i still had problems with 1 or two of the screws having no middle ground.

Tapping has gone - sounds much more normal and idle is a bit less harsh but ain't great...

What is there left to do?

r1ch

2,916 posts

203 months

Saturday 17th May 2008
quotequote all
Air flow metres always make crap idle.

Uberloin

Original Poster:

39 posts

199 months

Sunday 18th May 2008
quotequote all
r1ch said:
Air flow metres always make crap idle.


so what do I do about this?

Also, should I buy some replacement adjuster screws?

r1ch

2,916 posts

203 months

Tuesday 20th May 2008
quotequote all
Just buy a new AFM, or a reconditioned one.

Just make sure you get the relevant one for your engine. 1.6 and 1.9 air flow metres are different (though they look the same, just have different codes)

Most of the time, the air flow metre is the cause of crap idling. Leave the adjustment screws for now imo. Head over to www.205gtidrivers.com if that doesn't work and ask on the forum, that websites a bible for all things 205.

shalmaneser

6,046 posts

202 months

Tuesday 20th May 2008
quotequote all
r1ch said:
Just buy a new AFM, or a reconditioned one.

Just make sure you get the relevant one for your engine. 1.6 and 1.9 air flow metres are different (though they look the same, just have different codes)

Most of the time, the air flow metre is the cause of crap idling. Leave the adjustment screws for now imo. Head over to www.205gtidrivers.com if that doesn't work and ask on the forum, that websites a bible for all things 205.
It's a 1.1 carb model, not a gti. It doesn't have a AFM.

Simes205

4,663 posts

235 months

Tuesday 20th May 2008
quotequote all
shalmaneser said:
r1ch said:
Just buy a new AFM, or a reconditioned one.

Just make sure you get the relevant one for your engine. 1.6 and 1.9 air flow metres are different (though they look the same, just have different codes)

Most of the time, the air flow metre is the cause of crap idling. Leave the adjustment screws for now imo. Head over to www.205gtidrivers.com if that doesn't work and ask on the forum, that websites a bible for all things 205.
It's a 1.1 carb model, not a gti. It doesn't have a AFM.
I wondered when someone was going to point that out.

Check the ignition side of things and also probably worth cleaning out the carb.

Uberloin

Original Poster:

39 posts

199 months

Thursday 22nd May 2008
quotequote all
Yeah - no afm on my car lol.

The point is, the idling was fine before. However, on long motorway trips the engine started to feel intermittently tired, which resolved somewhat when i blew hot air into the car. The coolant was done at the service and its not leaking and its topped up. That was only 10 months ago/9500 miles ago. I was told the valve clearances may need adjusting so with help I undertook a check. Some were a bit loose but acceptable adjustment was nigh on impossible - they were like switches on two of the screws - tight or lose. This is, i'm told a sign of worn adjustment screws which have developed an edge, partly because they havenot been adjusted in a long time. Either way I don't know what is causing the rough idle other than perhaps needing new spark plugs...

It has a service in a week. I have asked my mechanic to check and replace the screws if necessary. I don't think the carb needs a clean its performance is not awful and it has remained economical.

Thanks so far for all suggestions.

btw the ignition timing was done 1 month ago due to the belt slipping causing it to go way out.

Edited by Uberloin on Thursday 22 May 18:27