GolfGTIforum.co.uk
Model specific boards => Golf mk3 => Topic started by: JRW91 on 19 May 2013, 19:31
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Hi, i'm new to this forum, have read a lot on here but just never posted..
I've just recently bought a 1997 Mk3 GTI 16v with an ABF engine.
The car will not idle when the engine is cold, it just ticks over and then stalls. It will start with a bit of throttle and will drive off as long as you keep a bit of throttle on. Once it is warmed up (couple of laps around the block) it idles perfectly, and will start normally and go straight to a perfect idle.
So far i have cleaned the throttle body, given the car a full service (new spark plugs, oil change, oil filter, fuel filter)
I have scanned the car using the u281 scanner, nothing showing up on there.
I have checked all the vacuum lines. All seem to be okay.
I have taken the ISV of, given that a good clean. Although i think that this is where the problem lies..
There is no 'buzz' or 'hum' from the ISV.. nor does it vibrate. Could anyone give me some helpful tips on how to test to see if this is the faulty part? i.e how to give it direct current to see if opens/shuts?
I have a multimeter.. but don't really know how to use it :whistle: Could somebody give an idea of how to test that power is running to the ISV and that it is getting the correct signals? Something to do with ohms resistance? Just not sure what i am looking for. As there may be a problem with the wiring harness/loom? I have given a visual check :nerd: but cant see anything that looks suspicious.
If there is anyone nearby who would be willing to give me a hand that would be very helpful! There will be beer tokens involved :smiley:
Any help would be massively appreciated as its starting to drive me up the wall! Been working on it for a good week..
Thanks!
Jamie
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get someone with vcds to run an actuator test - this will keep opening and closing the ISV (you should hear that if you listen with your ear next to it). If it does not make a sound put your voltmeter to voltage (20V range) and measure if a voltage comes there when the actuator test is running. If not you're probably looking at broken wire (they are white and black).
If you get voltage there and it's not clicking then the valve is f**ked. you can try to clean in with brake cleaner, has helped a lot with ISV on my 2E when it had once acted up.
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Will i be able to run an actuator test using a cheap ebay cable such as..
http://www.ebay.co.uk/itm/FTDI-FT232RL-KKL409-1-OBD2-Cable-VAG409-Interface-VCDS-Lite-works-on-Vista-win7-/181050728196
and will this cable/software work with my car? As i understand VCDS lite has limited function?
Unless there is anyone in Southend/Essex who would be willing to run vcds for some beer tokens?
Cheers..
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yes should work with that cable, but not sure if vcds lite without registration will allow you to run actuator tests...
will try on my g/f's laptop if she lets me ... i have bitten the dog and spent 99$ to register it.
worth it really and if you struggle then you have support (and if you get a newer VW you can always upgrade to full VCDS .... actually it's 1$ cheaper to first buy the lite s/w and then upgrade :rolleyes: )
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Would be great to know if VCDS lite will allow me to run the actuator test before i buy the cable as i dont have $100 to shell out on the full software.
Already bought the handheld scanner but this only allows me to read/erase trouble codes.. Should've bought this cable in hindsight :embarrassed:
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VCDS lite will do the tests, just tried on my laptop (well that the function is available, as I only have a 1.8 AAM it won't allow me to test the N71 = ISV).... but only the registered version. The non-registered copy I ran in virtual PC mode came up with "Sorry! This function requires VCDS lite to be registred...."
However you can manually try the valve, have look which of the contacts goes to gnd (the black wire). put gnd to that one.... and then try 12v on the other (goes to the white wire), it should click (once) now and click again when you disconnect 12v again.
the valve does not have a readback - its just on or off that is why a faulty one is not in your fault code memory, it just does not know what state it is in .
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Could you explain how to manually test it in a bit more detail for me please, im really not very technically minded. Sorry..
Should i just run a wire from the negative side of the cars battery to where the black pin is on ISV, and a wire from the white contact on the ISV to the positive side of the cars battery?
Thanks for all your help..
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take the isv out - as i would advise against running from battery (if the two wires straight from battery touch you can cause quite a spark)
use an old audio system power supply that is roughly 10-15V... connect negative to the terminal where the black on goes to (to find out which this is put multimeter in ohm - resistance mode and measure the connectors in the plug against gnd e.g. negative battery terminal - where it shows 0 or very low this is the gnd one - obviously do this with battery disconnected)
then connect + 12 to the second pin in the isv... click - if not try to soak the valve bit in brake cleaner... take a slim glass jar for example, pour brake cleaner in and stand the valve in there - so that the electrics are not submersed.
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Right.. I took the ISV out.. hooked it up like you said, connected it up to a 12v battery charger i have. It buzz's and vibrates :)
So i guess this means that my ISV is actually ok..
So the next point of failure must be in the cabling leading up to the ISV.. Any ideas where to start with this, how to go about fixing or replacing?
Thank you so much for your help!
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stick your multimeter probes in the plug and set it to 20V DC meausrement. Then start the car and see if you have 12V there... might not show anything if it is a slow cheap one.... alternatively use an led test lamp (if you don't have one you can make one from simple components that will do the trick).
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Okay, plugged the multimeter in. Got a reading of around 7 but the car was erratically idling. Would it be a gunked up connection restricting the power?
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probably ok, if you're measuring dc.
the ecu pulses the output, to look at the waveform you'd need an oscilloscope.
have you checked the temp sensor already?
it's in a different location on the abf (since the manifold goes round the front) but the procedure is the same there.
you can measure the temp sender in situ at first (cold in the morning when it shows just about 50-60 and then when it shows 90).
http://www.motor-talk.de/forum/aktion/Attachment.html?attachmentId=719242
poor cold idle could be due to that as well....
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where is this thing located???i'd love a pic from the AAM engine as mine is the same. tried to find it on the net, but no luck.;)
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Cool, I will get testing that as soon as i get in from work :)
Only question is though.. again i'm still new to all of this, and cant find the answer on here, where on earth is the temp sensor on my 1997 mk3 golf gti 16v?
Thanks for all the help :)
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where is this thing located???i'd love a pic from the AAM engine as mine is the same. tried to find it on the net, but no luck.;)
look at the pdf i've linked... all in there (photos are actually from an aam but its the same for abs, 2e, ady, agg)
on abf I think it lives on the side of the cylinder head. would need to check but dont have time today, need to party ;)
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sorry i meant the ISV.
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Okay tested that! all seems to be fine with the temp sensor!
Found a broken vacuum pipe from the little nipple just below the ISV.. fixed that and now the isv seems to come alive when the ignition is switched to on.
Now it will not start at all though!!!!!
It is making all kinds of buzzing and vibrating noises, seems to be coming from one of the pipes running to the fuel rail?
I can no longer connect to the engine with my obd2 reader either!!
Major frustration!!!
Any help would be massively appreciated as i need this car to get to work.. now that it wont start im buggered!!
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(http://i1315.photobucket.com/albums/t588/jrw91/1_zps04b60860.jpg) (http://s1315.photobucket.com/user/jrw91/media/1_zps04b60860.jpg.html)
This is the pipe in question..
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That's the fuel return pipe... Doubt that's where the buzzing is from unless your injectors are randomly firing.. Which I doubt on the basis of your posts
Also the isv is powered by 5v feed controlled trigered by the ecu, if you've rammed 12v up its backside I doubt it's done it much good.... Although the are just a motorised stepper to produce an air gap that opens an closes, so can't see it mullering it to much, fuse 15 is the one for isv (engine electrics) I would have checked this but if you saying you have buzzing and your sure its isv then that's not the problem... They are quiet simplistic really
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The fuel pipe seems to have just sorted itself out on its own.. and the car will now start again.. all be it with a bit of throttle applied to stop it from stalling.
I have removed the ISV again and have left it since last night full of WD40 and capped off at both ends, hopefully this will really clean the bugger out.. i will dry it and reattach it tonight to see if this has helped at all.
Did have 7v running to the ISV so i don't think it will be the fuse, although i will check it just in case.
Thanks for all the help guys.. will keep you all informed of any changes, in the mean time any more helpful ideas would be appreciated!