mr2haz 0 Posted April 26, 2008 My GTI 1.9 has only covered a few hundred miles in the 6 months I have owneded it but is has never run right. When warmed up the idle is all over the place and when coming to a stop the revs drop and the engine cuts out. I have just replaced the SAD but still no joy. It has also had a service when I bought it including new sparkplugs and HT leads. What would be my next step? Share this post Link to post Share on other sites
welshpug 1,657 Posted April 26, 2008 check that the throttle switch is adjusted correctly and working, you should hear it click just as the throttle butterfly hits resting point. Share this post Link to post Share on other sites
mhyphenl 10 1 Cars Posted April 26, 2008 check that the throttle switch is adjusted correctly and working, you should hear it click just as the throttle butterfly hits resting point. Also I saw elsewhere on the forum that giving all the breather hoses and in particular all the airways in the throttle body a good clean helps, that sorted mine and I had the same problem, revs dropping to nearly nothing when you take your foot off the gas, especially if you do it suddenly! That and the throttle switch should sort it!! Share this post Link to post Share on other sites
mr2haz 0 Posted April 26, 2008 Ok, what does the throttle switch look like and where is it located? Share this post Link to post Share on other sites
philfingers 5 Posted April 26, 2008 A haynes manual explains the setup and is a usefulo thing to have. it's covered in there. If you do an advanced search you may find it on here too Share this post Link to post Share on other sites
2-Pugs 57 Posted April 29, 2008 Ok, what does the throttle switch look like and where is it located? It's a small black plastic case about the size of a small matchbox, bolted to the front of the throttle body, just behind the slam panel With the engine off, as you move the throttle just off 'fully closed' you should hear it click. If it doesnt click or clicks too late, try adjusting it by undoing the two small screws it's held on with and rotating it slightly Share this post Link to post Share on other sites
Last Legend 0 Posted April 29, 2008 Sounds like a faulty fuel pump to me,(under the rear seat) pull up,drop in a new one, get them for around a tenner on ebay. Share this post Link to post Share on other sites
mr2haz 0 Posted April 29, 2008 I'll give them both a go. Do you have a link to the fuel pumps? Share this post Link to post Share on other sites
nick 3 Posted April 29, 2008 I would say the fuel pump would be the last thing on the list. Do a search, there are loads of threads on this (most common) problem. I would make sure you have absolutely no air leaks on the inlet and the engine breather system (including the dipstick) then do as above with the TPS. If that is set just right, it is then a matter of juggling with the tickover screw on the throttle body and the mixture screw (air bleed screw) on the air flow meter, you will just hit a sweet spot with the settings. I tend to set the tickover at 1k then wind the screw in until it speeds up then bring the tickover back down to 1k again, just trial and error really. Nick Share this post Link to post Share on other sites
mr2haz 0 Posted April 29, 2008 Is there a specific way for checking for leaks on the inlet and breather system or do I just need to remove and inspect the pipes? Share this post Link to post Share on other sites
Rob_the_Sparky 9 Posted April 30, 2008 You have a non-sorted car so your problems could be caused by a number of things, some more likely than others. THe most common causes of poor idle are: Retarded ignition timing Running rich (number of things can cause this: AFM, ECU temp sensor and adjustment most likely) Air leak past the AFM Dead SAD will generally cause poor cold idle and good or high warm idle Air leaks are not common, usually seen as a result of engine bay work and forgetting to put back in the screw that mounts the oil filler. This screw blocks a hole into the plenium so if missing results in an air leak. I'd start by getting the ignition timing right. Then see if you can back off the idle mixture on the AFM and while there check all the breathers are clear. Idle speed adjsutments may stop it stalling and are quick (adjust the idle screw, NOT the throttle position end stop) but will generally only mask the problem. Makes it more drivable but may result in an over high idle speed. You should fix the underlying problem when you get a moment if you adjust the idle speed like this. Rob P.S. Does not sound like a fuel pump. Share this post Link to post Share on other sites
mr2haz 0 Posted May 5, 2008 How do I know if the oil filter screw is present? Is it under the oil filter and so I would need to remove the filter? Is it a big or small screw? I have noticed a whole on a mount above the filter that would take a large bolt, is this it? Share this post Link to post Share on other sites
2-Pugs 57 Posted May 6, 2008 The screw that's been mentioned here is near the oil filler, not the oil filter. Here it is, pointing out my finger: Look behind the oil filler, it's on the inlet manifold just where it bolts to the cylinder head. It's easy to leave out, I have done it myself, and the car will not run properly whatever else you do because there is a lot of unmetered air entering the inlet manifold. Share this post Link to post Share on other sites
adrian_gti 0 Posted May 19, 2008 thanks for that pic... my cti has had a similer problem so will check this out. Share this post Link to post Share on other sites
2052006 10 Posted May 22, 2008 Has your AFM been re-tracked? Best thing I've ever done to sort out my idle when warm. Share this post Link to post Share on other sites
Simes 248 2 Cars Posted May 22, 2008 (edited) It's easy to leave out, I have done it myself, I remember that a few years ago on the PSC forum! Edited May 22, 2008 by Simes Share this post Link to post Share on other sites
mhyphenl 10 1 Cars Posted May 22, 2008 I remember that a few years ago on the PSC forum! Excellent suggestions there, I was having problems with cut out when taking my foot off the gas with my clutch down. It would just die, but cleaning out the breather hose connections on the throttle body sorted it!! However I have also left the bolt out before but never put 2 and 2 together as it were!! Share this post Link to post Share on other sites
mr2haz 0 Posted June 1, 2008 I have just checked and oil filler bolt is in place so that isn't the problem. Share this post Link to post Share on other sites
mr2haz 0 Posted June 24, 2008 Is there anyone local to me who could have a look/help me out with this as I need to sell the car soon. Share this post Link to post Share on other sites
jackherer 543 Posted June 24, 2008 Possibly, where in Essex are you? Share this post Link to post Share on other sites
mr2haz 0 Posted June 24, 2008 I am in Ilford but I would come round to yours if that is cool? Share this post Link to post Share on other sites
mr2haz 0 Posted June 25, 2008 Problem solved! Removed, cleaned and refitted throttle body. I noticed a blockage on the throttle body where the pipe from the oil filler cap goes onto the top of throttle body. Thanks everyone. Share this post Link to post Share on other sites
mr2haz 0 Posted June 28, 2008 I have taken the car for a drive up the M11 to discover all is not well. On acceleration all is fine but holding the car at steady speeds the car judders. It is not a heavy judder but the car is going smoothly. This is at its worst at around 2.5k-3k rpm and is almost completely cleared by 4k. Any ideas on what this is? Share this post Link to post Share on other sites
jamiej 0 Posted July 1, 2008 my mk2 Golf did exactly that, you can accelerate through it though cant you, its only certain speed/RPM when it does it, right ? I think it was to do with an engine resonance and knackered engine mounts ... as rediculous as it sounds. I never sorted the problem on mine, i kinda just learnt to live with it, but the guy who bought it, said that he put a new mount in as it was required? ... whether or not that solved the problem. Hope this helps. Share this post Link to post Share on other sites