Clinically Dead: 1Z as a Nebelwerfer!

Hello everyone! My 1Z engine (just under 200,000 km) now only starts with a miracle. A while ago, half of the interior electronics failed (climate control, eSD, blower, etc.), and it wouldn't start then either. I bought a new Climatronic control unit on eBay and got wiring diagrams. The 'new' control unit didn't work either, so I used a multimeter, and after eliminating a faulty fuse with high resistance, the electronics started working again. But the engine still wouldn't start. I thought it might be related to the connection between the climate control and the injection control, but it probably wasn't. In any case, I can crank it for ages, and all that comes out the back is cubic meters of white smoke. I'm at a loss! I can rule out the mass airflow sensor and other fuses, as well as the timing belt tension and the glow plug system; those have been thoroughly checked. I received advice that the injection timing might be caused by the sheared-off nose of the timing belt pulley on the crankshaft... so maybe I should replace that. That seems logical, BUT if that were the case, wouldn't it have stalled a long time ago? AND why does it run, with full power and perfectly fine, except for occasional misfires, when I *do* manage to get it started? The other day, I even drove for an hour in the evening, but the next morning, it wouldn't start again... PS: Could it also be the control unit? It's been chipped (but has been running smoothly for the past 60,000 km, only 15 extra horsepower from 90 to 105 hp)???? I would really appreciate some specific advice. Before changing the wheels, which isn't a problem, should I have the injection timing checked by a good mechanic (like '5051')? Or should I just go ahead and replace the timing belt pulley? Does anyone know this problem? Thanks, Merry Christmas, Matze.

Head poetry?

'Maybe water is leaking into the combustion chambers overnight. I've experienced that before. Then, after being idle for a long time, it only started after a lot of cranking and it smoked like a steam engine. During normal operation, there were no noticeable issues. Then, suddenly, it completely failed. Nothing worked anymore. I replaced the seal and it ran again.'

What do the others say about it?

maxximat wrote:

... I received advice that the start of the engine knocking might be due to the sheared-off nose of the timing belt pulley on the crankshaft....

Have I understood correctly that the nose of the crankshaft sprocket is completely missing? And how are you planning to correctly align the crankshaft sprocket with the timing marks with that? Your ESP/camshaft timing is definitely going to be messed up!
I find it rather baffling that someone would drive that thing around the countryside.
But please continue driving it. The timing chain wheel might continue to rotate over time, and eventually, the valves will meet the pistons. Then you'll have enough time to start looking for a new engine.


Haehnleins "Kaltstart Megatread" should help you with your problem.

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
+
Okay, I'm ready. Please provide the German text you want me to translate.

I would like to join Bertil.

Have you checked relay 109, the bane of all TDI drivers' existence?

Okay, thank you very much for the initial tips. The issue with the head gasket is indeed still a logical possibility, but I hope it's not the problem, because I had it replaced preventatively (???correct???). But if it is, it would explain the white smoke. In that case, I'll check the coolant level, as that's where it would likely be leaking from. I've also considered the tip about the sheared groove in relation to the 'skewed valve' results, but I'll still check the valve timing, as it doesn't take long. My biggest hope is that it's relay 109, because I recently had electrical problems with a fuse having a high resistance, so I'll replace the relay just to be safe. Can anyone tell me exactly what that relay is for and what it powers? Where could I possibly measure the current draw from it? Does it click when I turn on the ignition? Thanks in advance, Matze.

When you're sitting in the driver's seat, you'll find the 'thing' on the left side, underneath the dashboard, near the fuses (at least in the G III model, so it should be the same for you).

The other questions will be answered by the species here.

Merry Christmas to all forum members!

Hello Maxximat!
I received advice that the start-up problem might be caused by a missing piece of the timing belt pulley on the crankshaft...., so it should be replaced at some point. That makes sense, BUT wouldn't it have already started if that were the case? AND why, for goodness sake, does it run with full power and perfectly fine most of the time, if it's actually 'damaged' like that?

The advice isn't bad at all. I had the exact same problem with my 1Z a few weeks ago (see also https://community.dieselschrauber.org/en/viewtopic.php?t=4616): excessive smoke until the doctor arrived, cubic meters of white smoke, but hardly any or actually no noticeable issues while driving. Nevertheless, after examining the fuel system and electronics, I simply bought a timing belt kit and a new crankshaft pulley and started the operation. Lo and behold, even though a 12.9 screw was installed, it came off easily with a normal 1/2-inch ratchet without any resistance and with minimal effort, and the pulley already showed signs of wear.
If you have diagnostic capabilities, such as VAG-Com or a 5051 scanner, then check the fuel injection timing or the duty cycle of the fuel injection control valve (measuring block 4, value 4, target LL 2...10). Otherwise... 200,000 km... How old is your timing belt? It should have been replaced at 180,000 km.

Best regards,
Dominique.

maxximat wrote:

AND why, for God's sake, does it run at full power and flawlessly, except for occasional glitches, when I finally manage to "get it started"?

It's been written before, but it's Christmas time:
While the engine is running, the EDC adjusts the fuel injection timing within a defined range, meaning it's not unlimited.
However, this is not the case when starting the engine, so any incorrect settings will immediately become apparent.

I just read your responses, and I'm relieved, especially about Dominique's opinion. I hope it's just that stupid timing gear, because I've already ordered it. I change the timing belt every 50,000 km, and I had a major service in March, including the head gasket, glow plugs, belts, pulleys, seals, etc. And it ran well since then! Well, until the day the air conditioning stopped working along with other components, and since then I've always thought it was the air conditioning, because according to the wiring diagrams, it also has connections to the fuel injection system! But I'll also try the suggestion about the 109 relay, because my friend who has to tow me already has a 1Z! By the way, does anyone have any other ideas, solutions, or does anyone know if there could be an electrical problem where, after a previous malfunction, the air conditioning might need to be somehow 're-registered' or something like that? Thanks in advance.

Hi everyone, I don't know if anyone is still reading this, but I wanted to quickly thank you all for the good tips and ideas, and wish you a happy new year! I can now confirm Dominique's experience: I was also able to loosen the sprocket (according to the manual, 90 Nm plus a quarter turn) with a ratchet. However, I was mistaken in assuming there was a groove in the sprocket. The sprocket is flattened on the inside on one side, and I noticed very slight traces that, in my opinion, indicate that it had been worked on (i.e., worn out) on the crankshaft. The crankshaft itself was undamaged. You can already see the problem when you check the timing more closely (as you need to remove the VDD to use a ruler, and the pump dowel should be inserted). In that case, the crankshaft simply comes loose. So, I replaced the sprocket, and Reais 109 also replaced it at the same time. The engine started up as if it hadn't been trying to test how easily I could get frustrated for the past two months. Everyone have a good year and safe travels. Best regards from the Mecklenburg Lake District, Matze.

Hi, great feedback!

Happy New Year!

Best regards, Rainer.