mk2

Yeah, it's going to happen to everyone I reckon. I spotted a ghetto strap fix on here a few years ago but can't find it. Was an elegant solution from what I remember. Anyone have any ideas where it might be?

You already have the immobiliser response code... it's the ECU that's given that code above, not the immob? Positions are the same, so you might be right. Might have been changed before? @lupogtiboy, do you have a relay position diagram? I can't find one for the Gti.

Yeah, the immobiliser... There's a pick-up coil around the ignition key barrel. You could very carefully, remove the chip from your only working key and tape it to the pick-up ring. But you might already be getting a key symbol on the dash? Not sure if your version of GTi has it.

Superb! ❤️👍🏻

You won't get a code for crank sensor... Fuel problem then?

Can you smell any fuel at the exhaust? If not, could be fuel system related, like pump, filter, pressure regulator, that sort of thing. Not ECU. Not temp sensor. Not ignition or plugs. And like @lupogtiboy says, crank sensor? You'll get no or intermittant sparks if it's the crank sensor.

You could add some washers to either push it down or angle it? Does your Hex work in other cars ok? Lupos use the k line for data with the standard power supply connections. So it should work. The power pins are different lengths to the others, so it is possible that the unit isn't pressed into the socket properly.

Could be switch indicator stalk assembly (there's a how to I wrote). Could be the light switch (it pulls out- in the off position, press the switch in, then while pressing in turn to on. Then pull it straight out...). Could be wiring. Can you flash or use high beam?

Yeah, it's a special bolt, with two different threads. They fail on every Lupo. Or the welded nut that it screws into falls off. I think I may have written a how-to with lots of pics, on here somewhere.

You did good 👍🏻🏅🎉😀 Mower ball joints?

Is that a tiny ball joint? If it is, there are loads of equivalents you could use... machinery joints, mower joints, door mechanisms etc etc. I don't have a GTi. More pics?

I go from below. Socket. One of the things I remove when pulling out the alternator... Let me guess- rusty and leaking swage join between the flexy hose and the steel pipe?

@RAB is the 3L expert... Your question has been asked quite a few times in the past. Search through @RAB's old posts and the answer is there. I think the system just needs recalibration, where the clutch actuator movement sensors are used. The 3L was never sold in the U.K.

Dead crank sensor won't affect power at all. so yeah, it does sound like there is a power problem. But where is the break in the supply circuit...? No idea. But the symptoms for ignition switch are the same. It's not the barrel, but the switch behind it. Apparently it is quite a lot of work replacing the ignition switch. Have you tried wiggling the switch with the key in? I have never ever seen a failed ECU, but there is always a first time.

Do you have a spare key? It does sound like the immobiliser. Starting then cutting off a second or two later. If it is, then one trick is to remove the transponder chip (super, really carefully) from inside the key and glue/tape it to the induction pickup around the ignition key barrel. It is also the way to have a spare key if you only have one transponder chip and need two keys, and don't want to pay VW $$$ for a new key. The other fault if it runs then cuts off randomly is ignition switch (power) or the crank sensor. Neither of these will throw a code on VCDS. Easy to change the crank sensor first? If you connect a light bulb to the solenoid coil, you might be able to see if it flickers or is deliberately turned off... It does sound like a wiring fault. Someone wrote a how-to change the ignition switch on here if you search. Not easy, but cheap! Bypassing the ECU injection pump solenoid control is interesting... How well does the engine run? The SDi is drive-by-wire, where the injection quantity and timing is directly controlled by the ECU. The throttle pedal is also just a sensor. I've never tried that experiment. I hope this is not a way to bypass the immobiliser. I've done experiments bypassing/disconnecting the injection timing advance and the injection pickup sensor; the engine runs really badly. late edit- just read the entire thread again. It does sound like the crank sensor?

Fairy liquid mixed with kerosene or diesel. Or to remove Diesel engine oil gunge residue, fairy mixed with cellulose thinners. No other washing up liquid works, only green fairy. I don't know why 🤷🏻‍♂️ But in both cases, low-medium revs, not a hot engine and a very light drizzle/spray into the air inlet to avoid flooding the engine. Does a nice job cleaning the backs of valves. They changed the formulation of brake and clutch cleaner to stop bad people making "phosgene" out of the stuff...

New batteries always help. Just keep an eye on it as flattening a brand new battery shortens its life a lot. Typically, you will get no fault code if the ignition switch or crank sensor is intermittent because the computer simply thinks that you've either switched off the engine (on purpose) or the engine isn't running. It uses the crank sensor to tell if it's running and set the ignition timing for sparks (and other stuff). Let us know what you find so we can all learn

My first thought about the flat battery is a "leaky" alternator. You'd need to confirm that by measuring the "off" current in the output cable. Should be less than a mA. Then I remembered that there is a known problem on all Lupos with the ignition switch, so might be that? Power to the lights switch cluster is the way to check that. The starting problem sounds like either the crank sensor or ignition system (coil?). But again, it could be the ignition switch being loose. You'll need to use some diagnostics like VAGCOM/VCDS.

@Rich can you get your verniers out and some pics...

There is a known issue with the rear brake shoes. The handbrake cable lever which attaches to the shoe, which then applies force evenly to both shoes via a connecting bar and through the self adjusting wear compensator wedge gets stuck. Chances are there is still a decent amount of material left on the shoes, but the wedge can't move to take up any slack because the handbrake lever won't budge. So when you apply foot pressure the hydraulic cylinder moves to just fill empty space- no brake action. The solution is to remove the shoes, both sides. Then once out work the handbrake levers loose on the rivet, so they move easily. Clean well. Apply a single drop of oil on the pivot, just to help it stay free. Reassemble. Fixed. Do the same if you buy new shoes. 👍🏻 Before you start, take a pic of each side once you have the drums off so you know where all the bits go. It can be confusing! Black plugs means the air:fuel ratio is wrong. Not enough air, or too much fuel. Most common reason is the coolant temp sensor which fails in EVERY vdub of that era. Could be blocked air filter, but unlikely.

Superb! Well, I'm not really surprised at that fuel economy considering that slab on the roof and all that weight in the back... I bet you were hitting bumps stops all the time. Love the pics. More please! Why didn't I hear about this before you set off?!

@Skezza knows how to do cluster mods if you ever want to swap it over to a miles based speedo...

Gorgeous!

Even though I don't own a GTi, I have a feeling they are they exact same as Polo 9N ball joints. @Rich and I and a few others here on CL were researching the similarities. If you can accurately measure one of yours (pics?), I still have an old 9N polo BJ sitting on my bench for reference. Regular Lupo BJs have a 10mm thread and a smaller cone. Welcome to Club Lupo pics of car?

How much €?