Abf over revving idle valve fully open.

certainly looks right, the part number for ecu sensor is 026906161.

if you get your ecu diagnostics up and running you can scan the codes plus check thru all the measuring blocks which show you all the ecu sensor inputs in real time, coolant temp, inlet temp, throttle position and engine speed being the main ones. lots of other interesting stuff to be read though

Who either fit the engine didn't put a diagnostic port on or I just can't find it. Is it something I can retro fit?

aye you need a wire from ecu pin 43, a live and earth to the port and thats it

New valve came today but as I plug it in it doesn't buzz. If I put a direct 12v feed to it it will snap open. Is this a dud part?

possibly, but do you see 12v on the isv black wire? need to test from this pin to earth as the white wire is pulsed

rubjonny said

possibly, but do you see 12v on the isv black wire? need to test from this pin to earth as the white wire is pulsed

Nothing on isv at all. Phoned up where I bought it from and without question they have sent another and don't even want broken one back!

Just put metre to the feed with ignition on and getting 11.7 volts. Is this right? Even with old unit if I touch wire on and off I can hear is open and close but one they have sent nothing unless I do it direct to battery.

that'll be ok yeah, next you can test for continuity from the white wire to the ecu pin 27

rubjonny said

that'll be ok yeah, next you can test for continuity from the white wire to the ecu pin 27

Great stuff

Waiting for new part to come so will plug it in and hope for the best but if its still the same and i check from the white wire what would be my next step.

the the black wire is ok and the white wire has continuity to ecu then you are getting unlucky with ISV or you have some ohter fault which is affectign isv function. diagnostics need to be installed asap

Put new valve on and takes a while to tick over and then doesn't drop below 2200 revs. What the hell am I doing wrong????

The part I bought is a cheap Chinese one for £60. I take it this is the problem with the parts I'm buying?

very possible, genuine VDO is what you want ideally but they'll be 3-4 times the cost if not more new

one thing to try since you have replaced the ISV is go thru the TB->ISV adaptation procedure, but again you'll need vag-com for this

Stop spending money, get your port wired in and check the codes and measuring blocks. then go thru the isv basic settings procedure, its in my sig 'abfbasicsetting.pdf'

dont forget to install the ABF label files so the measuring block labels are easier to understand:
http://www.clubgti.com/showthread.php?199583

rubjonny said

very possible, genuine VDO is what you want ideally but they'll be 3-4 times the cost if not more new

one thing to try since you have replaced the ISV is go thru the TB->ISV adaptation procedure, but again you'll need vag-com for this

Stop spending money, get your port wired in and check the codes and measuring blocks. then go thru the isv basic settings procedure, its in my sig 'abfbasicsetting.pdf'

dont forget to install the ABF label files so the measuring block labels are easier to understand:
http://www.clubgti.com/showthread.php?199583

Well I ordered a genuine vdo from a scrappers last night so will put that on first.  Can to talk me through how exactly I fit the diagnostic port as although it's only 3 wires I wouldn't know where to start. Thanks for all your help with this.

get the grey./white from ecu pin 43, add that to your port. live and earth you can splice to the ciggy lighter wirign as it is on a mk3 golf

ideally for an easy life grab the 16 pin port out of a later mk3 in scrappy, pull the ashtray and slide the plate sideways to find it.  chase the grey/white and yellow wires from it back to the diagnostics jumper block without cutting, and remove the jumper block too. plus take one of the grey/white single pin wires with a good length of wire to splice to your ecu wire.

follow the rer/white and brown wires back to where they tap into the dash harness and snip off. you should end up with this:


itsd a fair amount of work to chase the wirign out of the mk3 intact, but well worth it for when you come to wiring it back into the mk1!

Oh right that really does sound easy. Let's see if I can find a scrappers with one.

yeah wiring it in is easy, especially so if you get it out complete.

getting it out in 1 piece, well thats more of a pain! main reason is you got to take half the dash out the mk3 to get to the main dash harness, and once you get under the dash its a pain thanks to the knee bar which sits in front of the fusebox, so its a case of lower trims off and head in the footwell! drop the fusebox off its hangers that makes life a little easier.

dont be afraid to hack the hell out of the mk3 dash harness if it makes it easier to get the diagnostics wiring out, feel free to chop it up and generally ruin it, just make sure you dont cut the diagnostics wiring

rubjonny said

yeah wiring it in is easy, especially so if you get it out complete.

getting it out in 1 piece, well thats more of a pain! main reason is you got to take half the dash out the mk3 to get to the main dash harness, and once you get under the dash its a pain thanks to the knee bar which sits in front of the fusebox, so its a case of lower trims off and head in the footwell! drop the fusebox off its hangers that makes life a little easier.

dont be afraid to hack the hell out of the mk3 dash harness if it makes it easier to get the diagnostics wiring out, feel free to chop it up and generally ruin it, just make sure you dont cut the diagnostics wiring

Thanks again. Going to put port in as think very useful for the future but in the mean time hoping that when the genuine ISV comes tomorrow it will just work as so bad at this sort of stuff

Ok new valve came and sits at about 3000rpm. I now have a lot of smoke coming out the exhaust so really don't know what's going on. For someone with very basic mechanical knowledge what are my possibilities of what's going wrong and am o at point I need to take it to a garage?