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Discussion Starter · #1 ·
Im not sure if this is an electrical or engine problem so ive posted in the general forum.

Basically i returned from holiday to discover a dead battery tried to recharge it but after a couple of jump starts in 3 days concluded that it was dead. So i got a replacement battery fitted by the RAC, i know its easy to do yourself but not on the side of the road with no tools or battery [;)].

Since the new battery was fitted my car at idle the revs dip from 900 to about 600 a couple of times and level out. I think also the fuel consuption is up slightly and the car may have a litttle less power at low revs, but seems fine at higher revs.

Its been like this about a week now as i thought it could be because the fuel had been in the tank for 3-4weeks whilst i was away, but the tank has been emptied twice and refilled, to no avail.

Anybody give me any suggestions as to the cause and therefore the solution of this problem so that i can go armed to the garage with some information.

Many Thanks
 

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Have you taken the car for a good drive? Might be that the ECU needs to "re-learn" it's settings? iirc you need to take the car for a good drive, through the rev range in all gears.

HTH

Oh and by the way, iirc I'm sure you're not supposed to jump start the car as it can cause damage to the electrics...hope it's not this that's causing your problems
 

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Discussion Starter · #3 ·
Cheers for the advice dave.

Im pretty sure its been given a fairly decent drive, but i'll take it out and show it a good time on the way home from work tonight.

When i said jump start i meant from an RAC style battery pack rather than another vehicle so i should hope that thats not the cause of the problem because thats sounds expensive [:)].

Thanks again i'll let you know if it helps, any other thoughts?
 

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rough idle could also be a dirty throttle body...could just be a coincidenct that it happened after having to replace the battery. There's info on rough idling in my FAQ post, and some specific causes on the 1.8T
 

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Discussion Starter · #7 ·
Im a complete movice when it comes to things under the engine bay so how would i go about re-aligning the throttle body? is it as daunting as it sounds?

Dave looking at your thread there could be a few things to cause the problem but i need to find someone with vag-com in my area to help me diagnose it, any ideas of anybody with the cable and software around the norwich area?

Cheers for the advice folks.
 

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try unpluging the MAF first, and cleaning the air filter. then you need a vag com to re align the TB. but i read on the vortex you can re align without a vag-com, but it may be a myth, quote from VWvortex:

if you have a VAG COM i can explain how to do it... if not all you need to do is open the driver's door and put the key in and turn it to the on position but don't start the car. leave the door open and the key on but not started for at least (2) minutes. then turn the car off for 2 minutes and then finally turn the key on and start the car... you should be ready to go....

for vag com you need to go to engine(1) then to basic settings (4) and then type in "060" in the space for the block number and then hit go... it should take a couple of seconds and it should say ADP ok on the right when it's finished. oh and all this is done with the key in the on position with the car NOT started.

hope this helps

myk3
 

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Symptoms exactly the same as mine when battery "died" a few months ago. When battery is disconnected, the ECU reverts back to factory base settings. I followed instructions in Haynes manual and it solved the problem. Take the car out for a run of at least 15 minutes, covering as many engine speeds as possible. On completion, let the engine idle for at least 10 minutes and operate as much high-current drawing equipment as possible (power steering, windows, heated rear window etc) and get the engine fan going. After that, the ECU should have learnt proper settings. Worked for me, so best of luck.
 

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Discussion Starter · #12 ·
Cheers guys I shall give all these suggestions a try either at lunch or if not then this evening.

Many thanks for the advice i just hope its not another expensive problem with my motor and that one of these things fixes it.
 

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if you have a VAG COM i can explain how to do it... if not all you need to do is open the driver's door and put the key in and turn it to the on position but don't start the car. leave the door open and the key on but not started for at least (2) minutes. then turn the car off for 2 minutes and then finally turn the key on and start the car... you should be ready to go....

hope this helps

myk3
Has anyone tried this? Does it work? I think I need to clean my tb but have been a bit reluctant in the absence of vag-com

Thanks & appologies for hijacking your thread
 

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Discussion Starter · #15 ·
if you have a VAG COM i can explain how to do it... if not all you need to do is open the driver's door and put the key in and turn it to the on position but don't start the car. leave the door open and the key on but not started for at least (2) minutes. then turn the car off for 2 minutes and then finally turn the key on and start the car... you should be ready to go....

hope this helps

myk3
Has anyone tried this? Does it work? I think I need to clean my tb but have been a bit reluctant in the absence of vag-com

Thanks & appologies for hijacking your thread
I will be giving all these suggestions when i get home this evening so i'll post up the results for you. I may as well try it, whats the worst that could happen.......
 

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Ideally you do need to align the throttle body using Vag-Com. Unfortunately you do need Vag-Com to align it properly, we covered this a couple of months back in a thread that I can't find!! doh.. Anyway, someone on Vortex made some videos proving that the bonnet / door open / ignition on procedure simply primed the TB for use. I've got the vids on my HD if anyone wants them to host
 

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Discussion Starter · #17 ·
Right I tried these suggestions last night and it has improved the idle of my car but not made the problem go away entirely.

So my next course of action will be to take my car out for about an hour of fun driving at the weekend to see if i can teach it a lesson.

Failing that i will have to pester somebody in my area who has a vag-com.

Does anybody know if driving my car in this conidition will damage it in anyway?

Once again thanks for the advice
 
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