Poor starting and erratic idle

[stephenrs2]

diagnostic help required.

My car (RS2) has developed starting issues, which seam to be getting progressively worse. typically when cold the car will not keep the engine running unless you keep the car at 2000rpm for a few minutes, after which it can still idle roughly. When arriving at junctions and dropping into neutral the idle will hunt and sometimes cut out. When pulling off again the engine will bog down, although not all of the time.

Additionally it can give a fairly violent missfire when you are trying to accelerate hard.

Any ideas what may be causing this problem?

I have been to the Audi main dealer here, who tested the electronics on vagcom and he came up with nothing.

this is driving me nuts as it is getting worse not better, your help would be appreciated.

Regards
Steve

[VaudiGR]

the erratic idle could be from the ISV valve.You must take it off and clean it with carb cleaner spray.
The misfire could mean a lot of things,but adding the fact that you also have problems in acceleration,you probably have some vaccum hose cut or damaged.Check or change with samco 4mm vacuum hose all hoses,and clean the ISV.

On cold start the problem could also be a faulty temp sensor which is located at the back of the motor block,part white.you could try to change that as well which doesnt cost much.

usually these problems are often with this car and dont come up on the diagnostic.try to look for these things i mentioned above

cheers
Vasilis

[stephenrs2]

I've already changed the temp sensor at the rear of the block, which made no difference. I've also fitted new spark plugs, and discovered an old one was loose, again no better.

I'll take a look at the vaccum lines ans ISV, where do I get the samco hose from?

Regards
Steve

[AlWyn]

Samco RS2 hoses are special order only from S2 Central user name on the S2 forum (adu hoses same as late S2 aby) Take off your whole maf and leave it overnight submerged in a bath of IPA (isopropyl alcohol) dirty wires and internals of the maf affect measured air flow and mine were filthy (also get about 4-5 more mpg now plus some extra poke) cheap and easy job, get the IPA from any decent chemists.

[stephenrs2]

can I soak the ISV in isopropyl alcohol as well as the MAF, or do I have to strip it to clean it? Now have said alcohol so will be doing the MAF tonight.

[AlWyn]

Stephen, chuck it in, the IPA isnt highly corrosive or anything it just lifts dirt and cr-p off anything it comes into contact with. Computer bods spray internal computer components with IPA and as soon as its dry its non- flamable (when its wet, well shall we say it goes up well) Take it youve no boost leaks?

[stephenrs2]

not sure about the boost leaks, I used to have a Maestro Turbo (it really was a great car!) and it had a boost leak which is not the same as this.

When I get the MAF and IVS back on I will be able to take it for a run and test. Given that disconnecting the ISV made such a difference, I am convinced I'm on the right track. Fingers crossed.

Steve

[AlWyn]

Maestro Turbo! your not allowed to use that sort of language on here! Only joking, i remember a whole group of Cosworth boys laughing at one that was up at Goodwood. The car ran 300+ brake and the Ford boys werent laughing as it passed most of them on the track! Moto build or something iirc. Keep us all posted re your RS2 probs.

[stephenrs2]

As it happens my Maestro came from Moto Build, along with their race tuned engine and hybrid turbo. I didn't run it up at the 300bhp range, as I never had their bottle to wind the turbo up that much (they tended to snap camshafts over 300 bhp) so I kept mine at a very respectable 270bhp. I always used to enjoy the look of suprise when you pulled away, from supposedly quicker cars, rather the same with the uniniciated for the RS2 performance.

I imagine them saying "How did that family estate car just pass me?"

[VaudiGR]

you can find any samco dealer wher you can get a 4mm vaccum hose.That is not needed to be a special order from the s2forum.buy 2-3meters of that and replace every vaccum hose you find.I also use plastic fasteners everywhere to secure them in place(sometimes not needed though but just in case).

[stephenrs2]

no problem, I've tracked one down via the Samco in France.

Steve

[stephenrs2]

finally got to the bottom of all the problems, and thought I'd share the results with you.

The misfire was being caused by a loose spark plug, a nice cheap fix, although I did change them, as I had gone that far.

2nd problem re poor starting etc, was down to a failed MAF. I had a new one fitted by Audi main dealers in France, including their time to fault find and then set my car up afterwards, a very cheap 275 euros. the MAF itself was 158 euros, is this cheap?

Anyway car now running like new so well happy.

Cheers
Steve[/b]

[AlWyn]

Sounds good to me Steve. Enjoy the performance and the sunshine