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Model specific boards => Golf mk3 => Topic started by: mani12354 on 11 May 2011, 08:45

Title: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 11 May 2011, 08:45
Hi everyone,

this issue on the car is properly haunting me :| when its idleing it miss firing, when held at 3rpm when driving it shake backwords n forwards, also running really rich. PLUS! it wont connect to the computer for some odd reason :|

i have cleaned the following and done a compression test.

new fuel filter
new fuel pressure regulator
new spark plugs
new distributor cap
new ht leads
cleaned the injectors
cleaned the throttle body
new battery

had it seen by 3 mechanics << LOL! :shocked:

i so need help with this car i dont no what more it can be oh plus the car aerial has no signal for a bizzarre reason :|

cheers

mani


Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: thai-wronghorse on 11 May 2011, 09:13
Ecu related problem maybe?
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 11 May 2011, 09:18
where can i get a new ecu from???  :shocked:
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: thai-wronghorse on 11 May 2011, 09:24
It could also be a vacuum leak, id check all the hoses before buying another ecu although that wouldn't explain not being able to connect to Vagcom.
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 11 May 2011, 09:28
question is which vacum  could it be?
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: thai-wronghorse on 11 May 2011, 09:29
IF it is the ecu then heres a few but remember they're not all the same so check the code on yours plus you'll need the matching immobilisetr key chip with it or you'll have to get it reprogrammed.

http://shop.ebay.co.uk/i.html?_from=R40&_npmv=3&_trksid=p3902.m570.l1313&_nkw=abf+ecu&_sacat=See-All-Categories
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: thai-wronghorse on 11 May 2011, 09:32
question is which vacum  could it be?

The thin cotton covered tube that runs from the rear of the throttle body to the ecu quite often perishes due to the heat from the manifold below.
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 11 May 2011, 09:38
thing is also u smell petrol around the engine bay! :O like it over fueling
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mk2_abf on 11 May 2011, 10:05
throttle position sensor  must be faulty try unplugging it the revs might drop could indicate a fault
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: Leon27 on 11 May 2011, 10:22

Ecu related problem maybe?

+1 to that. You tried a new ECU relay? If you push through from 3k to after 4k and the fault clears then try a new relay (no.30). Fuel smell could be a secondary fault or something else is wrong.
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 11 May 2011, 10:56
i cleaned the throttle position sensor and tryed disconnecting it still didnt solve my problem  :shocked:

@ leon, umm where can i get a new ecu replay from??
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mk2_abf on 11 May 2011, 11:43
another thing to check is the wiring from throttle postion sensor follow where it goes they usually clipped to the rocker cover, theheat off the engine over time can make the wires really brittle and start to break down
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: Leon27 on 11 May 2011, 16:51
another thing to check is the wiring from throttle postion sensor follow where it goes they usually clipped to the rocker cover, theheat off the engine over time can make the wires really brittle and start to break down

Happened on mine as well. Well worth a look.

ECU relay 30 is availiable from VW or Trade Parts Specialist (TPS) Not that expensive £15ish? and very much over looked when diagnosing
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 12 May 2011, 08:37
 :grin: i dont no what i done but i fixed the mpg geting between 30 - 40 mpg on the motorway :D but the stuttering is still there at 3.000 rpm : :cry:
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: trigolf on 12 May 2011, 09:38
As previously mentioned replace the vacum pipe that runs from the back of the inlet manifold and along the bulkhead to the ECU  - which sits under the plastic trim at the bottom of the windscreen. Check the crank sensor wiring loom  - it gets brittle from the heat from the engine block.
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 12 May 2011, 09:47
i checked the vacum pipe thats why im geting better mpg and where is the crank sensor any pictures???  :undecided:
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: thai-wronghorse on 12 May 2011, 10:42
Was the pipe split or loose then?

The crank sensor is situated just behind the oil filter to the left. Its a lot easier to access by removing the front engine mount bracket.
Title: Re: mk3 2.0 gti 16v abf (96) idle and miss firing at 3,000rmp
Post by: mani12354 on 12 May 2011, 10:59
nope it was tight as anything  :O but i noticed one thing when i went to start my car after it didnt start then i banged the terminal on the battery and it sorted out my mpg do u fink it could be a lost batterry?