hi I am having bad idle issuies with my 99 1.8t agu,basically as soon as the car is started the revs go up and down from 1400rpm to 2000rpm droping up and down really fast between this rev range then once its calmed down maybe 60 seconds later, when its back to 900rpm and I touch the revs it then gos upto 1400 rpm again stays there for 3 seconds then drops back to 900rpm,then when I start driving it will stick at 14000rpm at junctions and can pull away in 1st or 2nd gear without really needing to use the accelerator,i have recently replaced temp sensor for a original one as first one I bought was cheap rubbish,the temperature does seem to take a while to get to 90,also changed camshaft sensor for original both parts ordered from vagcom,I have no error codes now,i was thinking thermostat but woudnt the car overheat?,i also have bad juddering under heavy acceleration but that's another story, would really appreciate some advise thanks
help needed pls really bad idle
- Thread starter makster1978
- Start date
Try cleaning the throttle body and doing a throttle body adaptation first.
14000 rpm at junctions, I'm guessing you mean 1400 rpm
14000 rpm at junctions, I'm guessing you mean 1400 rpm
lol yes 1400,had the car in vagcom last week and they said they cleaned the throttle body,the car was in for the juddering problem I have but left there unfixed they tried new maf new ignition module and replaced fuel filter and pipe,what does the adaptation involve? thanks for reply
Yes there is, there's a stepper motor in the throttle body that opens the throttle a little bit to allow it to idle.
The proper way to do the adaptation is with VCDS.
The poor mans way is to unhook the negative battery terminal and the plug on the throttle body for 10 mins.
Plug them back in and turn the key to the first position and leave it there for about 4mins.
You should here the stepper motor in the throttle body cycling through its sequence.
If that doesnt help i'd be checking spark plugs, vacuum lines, pcv hoses, coils, injectors, FPR, etc.
The proper way to do the adaptation is with VCDS.
The poor mans way is to unhook the negative battery terminal and the plug on the throttle body for 10 mins.
Plug them back in and turn the key to the first position and leave it there for about 4mins.
You should here the stepper motor in the throttle body cycling through its sequence.
If that doesnt help i'd be checking spark plugs, vacuum lines, pcv hoses, coils, injectors, FPR, etc.
"Poor man's way" of adapting a cable throttle body after cleaning it (no need to disconnect battery) is after refitting it, turn the key once, wait for the TB to stop making noises, then it's aligned.
Coolant temp has to be between 5 and 95 degrees aswell.
Yeah, it should just do the adaptation on the first turn of the key but it doesn't always seem to work, disconnecting it seems to force it to adapt maybe its just a placebo
Yeah, it should just do the adaptation on the first turn of the key but it doesn't always seem to work, disconnecting it seems to force it to adapt maybe its just a placebo
cheers guys looks like its the poor mans way,i think vag was pulling my chain saying they done a load of tests £100 down and drove car away the same as it went in there,really frustrating,i am going to change the thermostat,i hear lambda sensor sometimes doesn't throw a code up so that's probley next concidering the mpg is bad and nearly failed mot on emissions 2 days after i serviced it,car cut out this morning as well in 3rd gear going to work
disconnected the negative and throttle body sensor nothing happened and couldn't here anything at all
Did you reconnect and then turn the key to the first position and just wait, you should hear it then
yes wernt sure which to disconnect so did the top one and the bigger one underneath I followed your insructions with the battery and waiting for 4 minutes with the key turned and defernatly was no sound
Like this
It wont do it if there are any pending error codes and coolant temp needs to be between 5 and 95.
Now it works for me if i just disconnect the top plug, i can leave the battery as is and it resets on first turn of the key
It wont do it if there are any pending error codes and coolant temp needs to be between 5 and 95.
Now it works for me if i just disconnect the top plug, i can leave the battery as is and it resets on first turn of the key
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cool,not quite first turn of key doesn't light up the dash 2nd turn does maybe I will have try again cheers,was checking fuel preasure regulator tonight which looks shot at and a little nik in the small pipe to it but doesn't look like a air leak but I will change it I think,process of elimination now with no codes and vag not fixing it,nowere else to turn apart from here
just noticed your description under the link,the car was stood in the back for a few hours before trying so I will try it afer a run.appreciate the help
I couldnt get the adaptation to work last week either then I realised it was 3 degrees outside the car
