I have a mk3 golf gti anniversary 16v The key turns fine in the ignition barrel but it can take 1- 20 attempts to giggle it in the right place to get it started. It’s now still hard to start but just as soon as the engine starts it cuts out. I thought originally just replace the ignition barrel but could it be an issue with the ECU detecting the immobiliser so cuts off? Any suggestions welcome please.
Probably ignition switch failure, common on mk3s , but the immobiliser will need checking with VCDS/Vagcom for a 'engine start blocked by immobiliser' code.
do you need to do the jiggling to get the ignition lights to show up on the clocks? also when it cuts out, are the lights still on or do they go out? short term if you unplug the ignition switch and loop the red to the black that will switch on the ignition, then jump[ red to red/black that'll get it cranking. if it starts and runs fine then yep, its the ignition switch. Not too fun to change with the mk3 as its got spline adaptor, you can just about get to the switch screw in situ but its wedged deep between the column and lock housing. If you get a new switch you can plug it to the loom and turn it with a screwdriver
The ignition lights come on fine, it just the issue with the starting. I’ll have to check if the lights stay on afterwards. I’ll have a look over the weekend. Hopefully it’s it the ignition switch then nice cheap fix. Thank you RubJohnny
ah so it just wont crank? try switching on the ignition, then run a wire from battery live straight to the starter motor to get it cranking (or red to red/black above) if it cranks over every time you try then again its ignition switch. if it still cuts out after, then this may be the immobiliser as well! when you get vagcom plugged in if ecu flags immobiliser code then scan the immobiliser box address 25 and it will tell you why if its a key signal low error, bag another reader coil, they dont need coding in so straight swap
Just started the car again and once you have started the car you keep the key held still on fully turned right, the engine remains on. One you let go of the key the engine stops. Ignition switch is the issue?
yep sounds like it, the immobiliser is only active while the engine is cranking and a second or so after starting. once its idling you can move the chip away from the reader coil and it'll stay running just fine the ignition switch is a bit tricky, issue is with the spline adaptor pressed on you cant pull the ignition lock off to work on the switch. A decent gear puller should do the trick, the 3 legged pullers can do the job but its fiddly. I found clamping a set of mole grips loosely in palce butted up to the lip of the adaptor ave them enough to grip onto, but even then sometimes the adaptors are well stuck! Another way to attack it is if you remove the lower stalk trim and look close between the switch and the column you'll see the little screw buried in there. With a bent thin screwdriver you can just about reach it. To make life easier if you remove the nut & bolt holding the UJ to the bottom of the column you can pull the column out with the ignition housing attached then attack it off the car (can even leave the wheel and stalks on if you go this way)
