MK4 golf 1.6se 8v 1999 eratic idle (auto)

Evenin Chris :)

As mentioned about I have tried to do the alignment process and meet all the criteria to doing it eg no dtcs, battery level are all met etc but it gives me a error when accessing block 60. Has me stumped why its not letting me do it. A registered VAG COM VCDS lead from ross tech so not a cheap copy.

I'm starting to wonder if the TB is knackered somehow ... although on that hunch its far too expensive a part to gamble that on, although theres some on ebay for £80 last time I looked.

I wonder if the MAF could cause this type of problem as there a common fault item. From more searching on ukmkivs people say it could be the MAF, o2 sensors (theres 2 on mine each £120 from gsf) .. the ECU or a vac leak somewhere.

I think I'll disconnect the MAF and see if that improves things petrol wise as the ecu I believe will re-learn some basic settings. If it improves I wonder if thats grounds to replace that... or maybe log some data and compare normal readings.

Don't you just love the jobs which don't require this much effort lol...I do enjoy the chase but this ones driving me closer to lala land lol.

Sorry, I only skimmed the post, so missed that. Have you tried Ross-Tech? If you have a registered copy they may help. A couple of them watch the VCDS section of briskoda.net, so you could post there, including a full scan of your car. Maybe the block is different for your ECU?

How new is your VCDS? Is it a registered 4.09 with a serial lead or a later version with a USB (Hex+Key) lead?

What's your engine code? Is there a physical throttle cable or is it drive-by-wire?

Don't know. The symptoms you have are *just* like our Lupo did (except for the chnage in D, as the Lupo is manual) which a TBA cured.

Yep. Do that. Log the Lambda reading for the O2 sensors. Should be near as dammit 1 when warm, I think.

:-)

Hehe no worries I do it all the time aswell :) .. I gave them an e-mail but no reply yet. Might be the time difference I guess :) .. ahh I'll check out briskoda. I ddid try block 001 and 098 they all pop up but are not relevant for my car for the tb alignment as mines a dbw jobby. I only tried them out of interest and fristration lol

I'm using the latest vag com with a hex-can-usb bought from gendan on of ross techs suppliers. Very good aswell it is :) .. many Sunday afternoons gave gone playing with it .. the lead chappy :-p

Its the dredful everythings a pain in the arse AEH, its a physical throttle cable.

Yeah I know somethings wrong, theres not logical reason it won't let me perform the TBA, I meet all of the criteria but its just gives me an error pffft. I'm wondering if its the TB thats gone to TB heaven.

Will definitely check to rule out, my gut is leading me to faulty TB.

Thanks for the help, at least someone gave me some lol :) ... no one likes these niggly faults.

On Tue, 05 Oct 2010 22:58:15 +0100, Matthew.Ridges wrote= :

A quick check for any airleaks wouldn't be a bad idea.

Shakes head.

Been watching this thread develop - now why would a major problem just start. I refer to getting a "new" TB because it started to idle rough? Settings should not need any adjustment either. Just because you cleaned the TB. Unless you have fully dismantled the TB then it should be recalibrated correctly.

I would be checking for air leaks as well.

Its your handy work that created the problem and not something else. Go back over what you have done. New gaskets? make sure all the surfaces are clean, no old gasket left, hoses not split, hoses back in the correct position, have you broken something off when you made the repair?

Trust me, disconnecting or disturbing the TB can require a TBA on many VAG engines. Our Lupo played up in a similar way after the battery went flat. TBA cured it completely. Not a very sensible arrangement for sure, but it happened, and it has run properly ever since.

From

The vehicle's battery has been disconnected and re-connected *

The ECU has been removed and reinstalled *

The Throttle Body has been cleaned or removed and reinstalled *

The Accelerator Pedal has been removed and reinstalled

In some vehicles, the car will not run correctly, or may not run at all without performing a TBA after one of the above operations.

I'd *certainly* be checking for a leak before replacing the TBA though.....

I've just noticed that you say it's DBW, then that there's a cable.

If you have a cable throttle, you need block 098, not 060- from the Ross-tech site. Keep looking for a leak as well though.

OK this is the answer and why it happens.

When you clean the T body - spray and or rag as well, you are removing the deposit from the body.

After doing this, the position of the flap is altered ever so slightly.

Why - as the material builds up, the shaft which the flap is attached, this is connected to a computer at the end - plastic bit on the TB. Why its not noticeable as the car gets older, the computer learns and makes corrections ever so slowly.

Once you do a clean the TB the alteration is too large for the computer to compensate hence the erratic idle.

How to fix - you need to do a basic setup by attaching the computer to make those idle adjustments.

This you can't do yourself BTW.

Another hint is that some cleaners will enter the TB computer and dissolve the circuit board so be careful.

Hope this helps

Correct. AKA a TBA.

he should be able to: he has VCDS. This is the next bext thing to the dealer VAS machine.

Why didn't he do that in the first place -

He did.

Or rather, he tried to. He got an error accessing the block that should adjust it. It may be the procedure is different for his car.

BAH! I missed that!.. I have also been in to block 098 switched to basic settings and left it for over 30 seconds, usually a little message saying something in the right of the screen but nothing happens oddly.

I did :)

A wee bit harsh :)

Aparantly the TB on the mk 1.4 and 1.6 can be quite temperamental if disturbed from a lot of reading on ukmkivs it seems its quite a wide spread problem.

A new gasket was used, it was a rubber band type affair not the usual paper stle one so it was plug and play, cleaned up perfectly. Hoses are all fine, cannot find a vac leak for the life of me which is what I started initially suspecting due to the bouncing idle. Nothing was broken, and everything went back togetehr as it was, I'm pretty good at things like this and getting it all back together crrectly.

It was a relatively simple job to be honest so but turned into a git.

I've logged some live data so the maf is fine aswell. No error codes.

Bugger. I'd exepect 'ADP run' to be displayed.

Hi Chris, I really appreciate all the help :)

My thoughts exactly :-/ .. I'm wondering if the TB is goosed or possibly the idle control valve part. Theres a reputable vw scrap place I'm contemplating getting a used TB from and giving that a whirl and seeing how it goes, they seem to be going for about £50/60 which is not to bad. Although tommotor I'm going on another air leak hunt *the joy* usually bouncing idle points to air leak and have a good look around everything that was touched and see where I'm at after that and if that fails I'll give a new used TB a go :) and if that fails I'll get a bicycle lol.

New TB on today, it allowed me to align it in VCDS. Gave it a clean aswell, was from a breakers at a costs of £45 bargained down from £60 :) ... Looks like the spraying loads of carb cleaners in to the TB when cleaning it damaged the ICV/TPS doodah somehow I'm guessing.

But fingers crossed so far, its behaving absolutely normally.

..will post back any problems but alls well for once with the golf, big thanks to Chris and all who helped with this PITA problem.

In future I shall error on the side of caution and spray the carb cleaner on to a rag and wpe it as oposed to diresctily on to the TB as the can says. :)