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Model specific boards => Golf mk2 => Topic started by: hasekna on 08 September 2009, 18:52

Title: Abf cutting out
Post by: hasekna on 08 September 2009, 18:52
Hey guys well I've got my mk2 abf on digi up and running, have been generally sorting lil bits and bobs out with it. It's developed a slight problem. Somtimes when i go to pull off, when i initially press the throttle(so its litterally just beginning to open), it'll just lose everything and nearly stall, but on continueing to press down the throttle it then picks up again and revs fine. It somtimes does this on slowing down to turn off on a junction, it'll nearly die. Any ideas? I've changed the fuel pump today and it's still a bit like it. When the coil blew we took off all the ignition system to check it and somebody noted that the dizzy cap was worn, could this be the cause of my problem? It's annying when trying to pull out of a junction or reversing, because i'm having to rev it high to keep going.

Cheers, Paul
Title: Re: Abf cutting out
Post by: K3VWT on 08 September 2009, 20:14
Sounds fairly typical of a weak mixture. You might have an air leak in one of the pipes attached to the inlet system.
Title: Re: Abf cutting out
Post by: Diamond Hell on 08 September 2009, 21:33
Has the throttlebody been cleaned out?

Have you checked the ISV is functioning?

VAG-COMed it to see if it's whining about anything?
Title: Re: Abf cutting out
Post by: hasekna on 09 September 2009, 12:06
Cheers for the replys. There's no vag-com port connected to it. I havn't looked at the throttle bottle yet what do you recomend just take it out and a bit or carb cleaner or somthing? Will the isv buzz like an 8v one? You say the inlet system, do you mean the pipe going to the ecu, one of the pipes i've blocked off, the brake vaccum pipe ect?
Title: Re: Abf cutting out
Post by: hasekna on 09 September 2009, 12:52
Hey. I've just been reading through the abf conversion checklist thread and looking at where the pipes go on the throttle body. It says the one on the back should go to the ecu, i think i may have put mine on the warm air flap. But i can't seem to find another connector for the ecu pipe to connect too. It's an abf from a mk3 L-reg
Title: Re: Abf cutting out
Post by: hasekna on 09 September 2009, 13:06
The pipe i'm holding is the ecu pipe, is this going to the right place? There dosn't seem to be anywhere else to plug it into?

(http://i87.servimg.com/u/f87/12/27/73/07/dscn1429.jpg)
Title: Re: Abf cutting out
Post by: rubjonny on 09 September 2009, 13:27
that vac pipe is for the vac canister which i assume you have binned, the ecu vac connection is either on the back of the rocker cover if its a later one, or it comers off a nipple on the chunky brake servo pipe non-return valve on the early ones
Title: Re: Abf cutting out
Post by: hasekna on 09 September 2009, 13:37
So the one where my finger's going to?

(http://i87.servimg.com/u/f87/12/27/73/07/dscn1510.jpg)
Title: Re: Abf cutting out
Post by: hasekna on 09 September 2009, 14:00
Ive just tried swapping them pipes over and it seems a lot smoother and responsive, hopefully that's it fixed lol! Thanks for the help.
Title: Re: Abf cutting out
Post by: danny_p on 09 September 2009, 14:30
that would explain it, the ABF ecu is speed density based if it;s vac line isn't connected to the manifold where it cannot get a true manifold pressure reading it will get pissed off
Title: Re: Abf cutting out
Post by: hasekna on 09 September 2009, 19:03
Have been riding about in it a bit more today. It still does it. It seems to run fin on start up, but once it's warmed up so to speak it occasionally idle's lumpy and drops away when i first press the throttle? Have had a good look round all the inlet pipes and everything seems ok.
Title: Re: Abf cutting out
Post by: danny_p on 09 September 2009, 21:34
IAT ??
Title: Re: Abf cutting out
Post by: hasekna on 11 September 2009, 17:46
IAT ??

What's that mate?

After driving it a lot more now, i've realised the following.... 30 odd miles to a tenner isn't right! I think it's running massivly rich. When I bought the mk3 the bloke said that it failed mot on emmisions, this is proberly why lol! He said that the lambda sensor needed replacing, could a duff sensor cause this sort of problem. Could the ecu go into some sort of safe mode whereby it chucks in loads of petty to er on the safe side? Also, if you guys do think this is the case, would you advise trying one out of a scrappy ect?

Cheers
Title: Re: Abf cutting out
Post by: oakgreengolf on 11 September 2009, 17:48
what are the plugs like?
Title: Re: Abf cutting out
Post by: rubjonny on 15 September 2009, 11:20
if you disconnect the sensor it'll go into a safew map, it wont be ideal but it certainly shoulnt use that much fuel.  i think you might have to break out the multimeter and do continuity testing on the ecu pins

http://vwtech.no-ip.info/downloads/g3abfecu.pdf
Title: Re: Abf cutting out
Post by: hasekna on 15 September 2009, 18:55
I've disconected the lambda and it seems to run a bit better, dosn't stall out at all now. still tries to die now and again, but generally its ok, I don't think it's running quite as much petty now either. When i bought the mk3 the bloke said it had failed the mot on emmisions, and that the garage had said it needs a new lambda. Which ecu pins should i do, all of them?
Title: Re: Abf cutting out
Post by: Diamond Hell on 15 September 2009, 21:25
Did you just hook up the lambda out of the donor?

If so you need to replace it by the sounds of it.  If the lambda has failed it'll run like a bag of spanners until you disconnect it.
Title: Re: Abf cutting out
Post by: danny_p on 15 September 2009, 21:54
new lambda needed then.   they get pissy with duff ones.    then leave the battery disconnected for 1/2 hour  then reconnect and turn ignition but dont start it ,  open throttel fully - hold it there then release and turn the ignition off.  then  start it