safety69 Posted February 7, 2007 Report Share Posted February 7, 2007 I have a 1997 1.6 a3 and its got a problem, and i can't pin point whats causing it. The problem is, that when the car is idling if i touch the accelerator sometimes the idle goes erratic, and sometimes drops so low the car will stall. I've had the throttle cleaned out, and also a full diagnostics check and showed no faults. I thought it maybe could be the mass air sensor, but surely would have came up with a fault code. any help much appreciated, to help me solve this problem. cheers Link to comment Share on other sites More sharing options...
safety69 Posted February 7, 2007 Author Report Share Posted February 7, 2007 could it be the ecu? Link to comment Share on other sites More sharing options...
kite Posted February 7, 2007 Report Share Posted February 7, 2007 Try running the car with the MAF unplugged if its better, the MAF is fooked Link to comment Share on other sites More sharing options...
safety69 Posted February 8, 2007 Author Report Share Posted February 8, 2007 tried it without the MAF plugged in, and is actually worse than with it plugged in. its not nice to drive because everytime you pull away you have to rev up a bit more to make sure the revs stay up and doesn't stall. anyone have this problem or know anything else which i could maybe check, starting to think more and more that maybe its the ecu playing up Link to comment Share on other sites More sharing options...
safety69 Posted February 8, 2007 Author Report Share Posted February 8, 2007 any ideas of what i could do, taken to audi and they say they would change the throttle body and MAF, but can't guarantee any results. Link to comment Share on other sites More sharing options...
kite Posted February 9, 2007 Report Share Posted February 9, 2007 What about trying a local independant. Link to comment Share on other sites More sharing options...
weedavey Posted February 12, 2007 Report Share Posted February 12, 2007 I'm having a similar problem. Here is my original post. Idle Problem Hi guys. Looking for some help on an idling problem. Sorry about length of post but I want to give as much detail as possible. Sitting comfortably? Last weekend I disconnected the battery on my 99 A3 1.8T. I gave it a good charge with the cold snap coming up, only took about 3 hours trickle charging. I put the battery back in and this is when the idling issue started. When the car is cold, i.e. the choke is on the car is fine. As soon as it warms up driving is normal but when I go to stop, the rev counter bounces between 1000rpm and 500rpm. I mean the needle will bounce between the two until the car comes to a complete stop!! Once stopped the car will idle normally!! The engine hasn't cut out yet, but I'm worried it will. Probably when I'm turning right, across the path of a speeding bus!! It's so strange. As soon as the clutch goes in it starts to do this and it will keep doing it while the car is moving. Once I come to a complete stop it's fine. I'm guessing it's a sensor. I'm no mechanic though. I don't want to go to the dealer as they're just too over priced. A friend is a Peugeot mechanic and he connected a SnapOn diagnostic reader to the car this morning. The only fault code it picked up is P1602 Intermittent voltage low. From reading around this could be to do with me disconnecting the battery? Does this sound right? Link to comment Share on other sites More sharing options...
weedavey Posted February 12, 2007 Report Share Posted February 12, 2007 I've been scouring the web for possible solutions to this. The two most common "possible" reasons are... Faulty MAF or Vacuum pipe leak. The mechanic who checked for fault codes for me said there may be a leak in the vacuum pipes. He had a brief look but it might be worth a proper shifty. As for the MAF I disconnected it about half an hour ago and the problem was still there. I THINK I can rule it out. Can anyone confirm that with the MAF out I should have at least experienced different symptoms? Is there an easy way of checking for pipe leaks or cracks? Link to comment Share on other sites More sharing options...
safety69 Posted February 12, 2007 Author Report Share Posted February 12, 2007 forgot about the vacuum pipes! I'm in the same boat as you, its a hard problem to pin point. it could possibly be one of the hoses, with the weather temperature up and down can cause the hose to expand and contract causing it to crack/split. I'm going to take a look at mine tomorrow. Link to comment Share on other sites More sharing options...
weedavey Posted February 12, 2007 Report Share Posted February 12, 2007 I'll have a look too by the weekend. Not that I know what to look for really but I'll see what I come up with. I'm thinking it has to be something like that if there are no fault codes from the OBD. Link to comment Share on other sites More sharing options...
safety69 Posted February 17, 2007 Author Report Share Posted February 17, 2007 I haven't had the chance to look at the vacuum hoses yet, but i'm going to check the vacuum hose on the throttle body and also the fuel pressure regulator, could anyone tell me if there are anymore that are worth checking? cheers Link to comment Share on other sites More sharing options...
AudiLad Posted February 18, 2007 Report Share Posted February 18, 2007 I had exactly the same problem with the idle! I have a 1998 Audi A3 1.6. I got the car services but the problem still remained. I then put some petrol treatment down the tank but made no difference. I got a junior mechanic to spray some stuff down the throttle body and the car was sweet as a nut! The revs were smooth and there was no eratic idling at all. When he sprayed some of the stuff down the throttle body the can was nearly empty so I presume it was not properly. A few months later the problem returned but only idles eratically sometimes and not all the time like before. I am going to get the throttle body cleaned properly this time and see how I get on. Hopefully the revs should stay smooth for much longer than before. Link to comment Share on other sites More sharing options...
safety69 Posted February 18, 2007 Author Report Share Posted February 18, 2007 cheers for the info mate. I did have my throttle body cleaned out and it did make the engine alot smoother and the idles behaved themselves. But it did return as you said, but about 2 weeks on, and i thought it has to be something else if i've had it cleaned out, but i most probably need a new throttle body. Link to comment Share on other sites More sharing options...
weedavey Posted February 19, 2007 Report Share Posted February 19, 2007 Well it pains me to say it, but after 2 odd weeks of the annoying idle issue it has disappeared!!! I was doing a lot of town driving on Saturday and after a couple of hours I noticed that it was not doing it!!! I tried and tried to get it to do it again but for 3 days now it has been fine!!! I did nothing. I thought on Saturday that the outside temp may have been warmer, but then I was up early on Sunday morning and there was a frost over here and again it was ok. I'm lost. I am terrified that the problem will return. I had no idea where to start looking for this and now I'm even worse off!!! Aaaaaarrrrrgggghhhhhh!!! Link to comment Share on other sites More sharing options...
STA3 Posted February 20, 2007 Report Share Posted February 20, 2007 Been reading your posts with interest maybe there is hope mine will sort its self out, only been running it for just over one week since the problem arose. Here is my original post http://www.tyresmoke.net/ubbthreads/showflat.php/Cat/0/Number/1084205/an/0/page/3#1084205 Link to comment Share on other sites More sharing options...
weedavey Posted February 20, 2007 Report Share Posted February 20, 2007 Hi STA3. Just read your post and we have exactly the same problem. It did however make two points click in my head. Firstly the temp guage. Mine was the same. Normally runs at 90 but while the problem was there it was about 70 or lower. I did notice that on Saturday when the problem disappeared the guage was at it's normal 90. I will look on the way home tonight to see where it runs. Secondly this also only began for me after the battery was disconnected. Anyone shed any further light? Thermostat? Idle temp sensor? Link to comment Share on other sites More sharing options...
STA3 Posted February 20, 2007 Report Share Posted February 20, 2007 Hey, don’t know if this helps but I took my car out this lunch time with my mate sat in the passenger seat with a laptop plugged into the VAGCOM port. Firstly no faults came up which I guess is good news so the temp sensor has been fixed, secondly the coolant temperature reading was exactly the same as my gauge was showing ie running cold so thermostat must be stuck, booked in for replacement next week. Also we logged the idle as the car cruised to a stop out of gear and the requested idle was a consistent 860 rpm but the actual idle was between 630 and 750 until the car came to a standstill where it settled at 860. I hope a new thermostat and then disconnecting the battery for 15 mins to reset the ECU will solve my problem. I have been told to leave the car idling for 10 mins after re connection whilst the ECU relearns its settings. Will let you know how it goes. Link to comment Share on other sites More sharing options...
weedavey Posted February 21, 2007 Report Share Posted February 21, 2007 Nice one! Well last night there was chaos on the roads around Belfast, it took me 2 hours 45 minutes to travel 4 miles home!!! So it wasn't the best night to be watching the temp gauge! I was out for an hour over lunch though and the temp never rose over 75. It always used to sit at 90 so I think you're on to something. Link to comment Share on other sites More sharing options...
weedavey Posted February 21, 2007 Report Share Posted February 21, 2007 I found some post where people were saying that the thermostat was affecting idle. They all mentioned that it also had an effect on fuel consumption. I've noticed mine has went down drastically lately, have you noticed this? There was this link also which lets you check the actual coolant temp using the aircon controls.I'll test it later tonight. Climate Codes Link to comment Share on other sites More sharing options...
safety69 Posted February 21, 2007 Author Report Share Posted February 21, 2007 I finally got round to cleaning out my throttle body myself using a throttle body cleaner, was very clean to look at, but the cloth showed alot of black build up. I then disconnected the battery and left it a short while before starting the car, and leaving it to idle for about 5 mins.Eversince i have done this i have had no problems at all, more to say the car is smoother. I'm glad i've got to the bottom of it, but has been very very annoying. It might be worth trying "Weedavey" if it's only occured since you disconnected the battery. Link to comment Share on other sites More sharing options...
Motormouth Posted February 24, 2007 Report Share Posted February 24, 2007 dupe post sorry Link to comment Share on other sites More sharing options...
Motormouth Posted February 24, 2007 Report Share Posted February 24, 2007 Can I join your club , mine has just started doing the same. Its a A3 1.8T 2002, it has a new lamba 2 yrs ago. I started the car this evening from cold and noticed revs went to and stayed at about 1500rpm, usually its around the 800rpm. Turned off car and restarted it still the same problem 1500rpm again. Drove it for a bit then parked up and idle was fine 800rpm'ish, turned car off and restarted and fine. Will see what happens next cold start. Frigging car had no problems with it for 2 years and then within the space of two months its been hit need new bumper, needed new alternator (still fecked) and now this grrrr Link to comment Share on other sites More sharing options...
weedavey Posted March 1, 2007 Report Share Posted March 1, 2007 Welcome to the Idle club Motormouth!! I'm due a service in a week or two, so hopefully that will help. Last night to add insult to injury I decided to remove my old car phone kit as I have a new bluetooth one. I cut the wires to the cradle and now my radio just says TELEFON. GREAT!!!!! Now I have to listen to the sound of my own voice!!! Link to comment Share on other sites More sharing options...
Vic Posted March 1, 2007 Report Share Posted March 1, 2007 Supermarket Fuel??! Link to comment Share on other sites More sharing options...
safety69 Posted March 1, 2007 Author Report Share Posted March 1, 2007 When i first heard about this fuel debate i laughed. But as the stories have unfolded, i've heard that silicon was present in the fuel and messing with the oxygen sensor. But since i've cleaned my throttle body and re set the ecu i've had no further problems. Link to comment Share on other sites More sharing options...
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