mk3 gti wont start

[Griff76]

Having loads of grief with my MK3 golf gti. Has been cutting out loads and now wont start. Been told its the immobilizer but had the alarm serviced couple of weeks ago!!! Tried to link to the ecu with hand held com but wouldnt link. Could it be ignition timing? has anyone got any ideas would be gratefull its driving me mad. Cheers Griff

[Wayne]

Start with the basics, have you got a spark and is the fuel pump running

[Griff76]

Start with the basics, have you got a spark and is the fuel pump running

all that seems ok, can bump it and runs fine but seems to cut out for no reason. Checked all earths wires under the bonnet etc. Wont even turn over with ignition. had problem with rev counter going crazy aswell!!!!!!! CHEERS GRIFF

[A8vgti]

Ok. So it will start off a push start? But not off the key? Have you tried a wire direct from the battery to the starter with ignition on? This is to test the ignition switch itself, not uncommon for those to fail.

The cutting out I would check the coil, it maybe breaking down, again common issue.

With regards to trying to connect wth the scanner have you tried to link up with the ABS ECU or the Airbag one? If you can connect to those it wont be the main wiring harness that you plug to. I had it with my anniversary, it turned out to be a broken wire at the fuse box end (small grey one plugs in at the top of the fuse box). If that all seems ok it could be the immobiliser box, if you follow the wiring back from the ignition ring reader it will be the other end.

This link maybe some help:- http://www.golfgtiforum.co.uk/index.php?topic=151417.0

[Griff76]

Cheers mate ill give that a go had the fusebox out today all the wires look good couldnt see the immobilizer box though. Had my alarm(toad) serviced recently,will my car have a seperate immobilizer coming off the ignition aswell? Ive got a gremlin somewhere!!!!!!!!

[A8vgti]

Cheers mate ill give that a go had the fusebox out today all the wires look good couldnt see the immobilizer box though. Had my alarm(toad) serviced recently,will my car have a seperate immobilizer coming off the ignition aswell? Ive got a gremlin somewhere!!!!!!!!

Depends on what year your car is? if its a AGG engine code it will have a immobiliser built into the car. It will be running the siemens management system. The immobiliser box it almost straight up from the clutch pedal, it will have two wires going to it. One from the reader (round the ignition switch) and the other going off to the fuse box.

All the issues could be connected to a immobiliser issue. Immobilisers cut power to different components. 1. starter motor 2. fuel pump these are standard. So yours not starting and the cutting out could be related to that?

My first port of call would be to connect to the ECU with your scanner. If all the wiring seems ok it could be you immobiliser box itself like cables in the link above. If you go through the thread there is a way to bypass the box and then you will be able to read your ECU.

[Griff76]

Sound for the advice bud, Ive had a mate round to look at it as well it starts if u bridge the starter with the ignition on think its the ignition coil. we put a voltmeter on it and theres power going in but not out. Maybe a new ignition(and keys) is this easy to get. cheers

[javalin]

if you bridge the starter and it starts - its not the ignition coil.  Its the wiring to the starter motor, or the ignition switch etc.....

[Griff76]

if you bridge the starter and it starts - its not the ignition coil.  Its the wiring to the starter motor, or the ignition switch etc.....

Yeah bud the ignition i was miles away!!! had a few beers n that. Ive got a 1.6golf in bits aswell (head gasket) so im swapping the ignition switch/barrell. cant get the splined collars off the steering column neeed to make a puller. Hoping this will sort it, ive got power going in  to the ignition but not coming out. Cheers 4 ya help, take it easy

[Griff76]

Cheers mate ill give that a go had the fusebox out today all the wires look good couldnt see the immobilizer box though. Had my alarm(toad) serviced recently,will my car have a seperate immobilizer coming off the ignition aswell? Ive got a gremlin somewhere!!!!!!!!

Depends on what year your car is? if its a AGG engine code it will have a immobiliser built into the car. It will be running the siemens management system. The immobiliser box it almost straight up from the clutch pedal, it will have two wires going to it. One from the reader (round the ignition switch) and the other going off to the fuse box.

All the issues could be connected to a immobiliser issue. Immobilisers cut power to different components. 1. starter motor 2. fuel pump these are standard. So yours not starting and the cutting out could be related to that?

My first port of call would be to connect to the ECU with your scanner. If all the wiring seems ok it could be you immobiliser box itself like cables in the link above. If you go through the thread there is a way to bypass the box and then you will be able to read your ECU.

its an agg but still couldnt find an immobilizer box, think bmy immobilizers ok unless its wired to the starter cos i can jump it or bridge the starter. im swapping the ignition had a voltmeter on it and its dodgy. Cheers bud, take it easy