BKD Won't Start After ZK Renewal

Hello, diesel experts,
Due to water in the first cylinder (as I inquired about previously), the cylinder head was replaced on a BKD 2.0 PD TDI engine this weekend. The cylinder head came with new valves from AMC. Additionally, the turbocharger and camshaft bearings were replaced during this process. All seals were also replaced, along with the timing belt kit including the water pump, glow plugs, and all screws that need to be replaced according to the repair manual, etc. The timing belt was installed perfectly using alignment tools. Otherwise, it can be assumed that everything was done professionally by experienced experts. However, despite all this, there was a setback at the end of the lengthy operation: the engine simply won't start. There is absolutely no spark!

All errors have been cleared, and there are no new errors in the MSG. The starter motor is turning as usual, but there is still no ignition. With starting fluid, it starts briefly, and then the control system seems to be working correctly.

Diesel is leaking from the adjustment screw on the tandem pump. After disassembling the tandem pump again and inspecting the distribution pipe in the common rail, it was observed that it is also wetted with fresh diesel. This confirms that diesel is being supplied to the injectors. However, without a pressure gauge, the pressure cannot be determined. Nevertheless, it was working until recently, so there is a suspicion that the tandem pump is not the source of the problem.

The troubleshooting continued, and we disassembled the ZK cover again to inspect the PDEs. Once again, the adjustment of the set screws was checked: set the pivot lever to the UT position on the PDEs, rotate the PDEs to the stop using the set screw, then rotate them back 180 degrees and tighten the set screw.

Then we moved on to the electrical components. We noticed that no error codes were generated in the error memory when one or more PDE connectors were disconnected. Is that actually normal? Also, disconnecting the camshaft sensor didn't trigger any error entries in the engine control unit (ECU)... is that normal?

Anyway, we're now at the end of our rope, as we don't have a TDI every day, and our experience with the machine is rather limited.

Was könnten wir übersehen haben? Bitte mal einfach ein paar Gedankengänge schreiben, sind für jede Hilfe dankbar. Feedback guaranteed!

Best regards,
Micha

Hello, is the fuel pump in the tank working?

Hello, is the fuel pump in the tank running?

He also needs to start in that way. The pump in the tank is a simple pre-feed pump with a maximum of 0.5 bar. The operating pressure, starting from approximately 2200-2500, is then only 0.25 .

The question about setting the timing: How was it done? Was the crankshaft pulley stopped using a wrench, and the timing belt locked with a mark on the timing belt wheel? Was the camshaft aligned with a dowel? Or was the timing set by aligning a mark on the flywheel with a mark on the camshaft wheel?

Background: 3- and 4-cylinder TDI pump-injector engines from VW Volkswagen, Audi, Seat, Skoda (or equivalent) - see the table below - only for diesel engines!
Not suitable for 2.0 liter TDI pump-injector engines with a cam shaft with an oval flywheel.

Here lies the difference with the KW marking tool!

When marking the top dead center (TDC) position, the TDC mark must be visible on the flywheel.

Even a completely misadjusted engine that's barely compressing can be started easily with the "Killer-Start" starter fluid.

The fuel pump is running, the filter housing is full, there is definitely a fuel leak, and fuel is spraying out of the control screw on the tandem pump.

@T3Surfer
The timing chain was installed with the crankshaft locked at Top Dead Center (TDC) using a crankshaft locking tool and the camshafts secured in place. TDC was additionally checked using a traditional method with welding wire through the spark plug hole (to ensure it hadn't reached the Upper Top Dead Center position). This particular BKD engine has a round timing chain wheel on the crankshaft, not an oval one. Afterwards, the tensioner was precisely adjusted, the crankshaft was rotated twice, and the positions were checked again (crankshaft at TDC, both camshafts can be locked in place – yes).

mullemaus wrote:

RedR32 wrote: Hello, is the fuel pump in the tank running? He also needs to start in that way. The pump in the tank is a simple pre-feed pump with a maximum of 0.5 bar. The operating pressure, starting from approximately 2200-2500, is then only 0.25

.

Why is it installed then?

@micha I would recommend running a complete diagnostic scan of all control units (ECUs) again using the diagnostic tool.

Why is it installed then?

To avoid a dead end. A PD, just like a CR, operates without a fuel pump. The early PD models, for example, didn't have one at all.

The actual fuel pump is the tandem or fuel pump 2 @ V277 .

Micha007 wrote:

The fuel pump is running, the filter housing is full, there is definitely fuel leakage, and fuel is spraying out of the control screw on the tandem pump. @T3Surfer The timing chain was installed with the crankshaft stopper at TDC and the camshafts pinned. TDC was additionally checked using a welding wire inserted through the spark plug hole (to ensure it hadn't reached the UTC). This BKD engine has a round, not oval, timing chain wheel on the crankshaft. Afterwards, the tensioner was precisely adjusted, the crankshaft was rotated twice, and the positions were checked again (crankshaft at TDC, both camshafts can be pinned -- yes).

What was the condition of the gearbox after being removed? Was it wet with diesel or dry from being stuck?
The welding wire OT search is not 100% accurate; please search more precisely for the SWING ARC OT marking .

@micha I would like to run a complete diagnostic scan of all control units (ECUs) again using the diagnostic tool.

I already did.
Besides the steering angle sensor on the ABS and LSSTG systems, there are no other errors. However, this can only be confirmed after a test drive.

The use of welding wire during the open trench (OT) search was solely to differentiate between the open trench and the utility trench (UT). The markings were positioned opposite each other on the installed marking tool.

Spark plugs: dry or wet? We hadn't even thought of that... I'll let you know what happens.

What's puzzling me, as I've already mentioned, is that with VCDS, I can access all control units and read all error codes, including those of the MSG (Motor Steuergerät). However, when I disconnect the PDE (Pressure Differential Sensor), there's no error entry.
One more time, the question to everyone: is this normal?
Only when I disconnect the main connector do I get 5 error messages: 4 glow plug errors and 1 PDE (Pressure Differential Sensor) error.

I just spoke with VW (the service department), and they said that their diagnostic tool supposedly detects a faulty PDE (which is a broken coil). They also claimed that a faulty wiring harness would supposedly be indicated.

Then I received the tip that it can take up to 10 minutes to bleed the system after changing the ZK (ignition coil), and that during this time, 2 to 3 starter batteries can be drained.
I haven't been trying for that long, but what do the experts here say about this statement?

Heute oder morgen Abend werde ich die Vorverkabelung erneuern, vielleicht hat die einen weg bekommen beim Umbau. Hat ja auch schon 150 runter und kann ja nicht schaden, weil davon hört man ja auch öfters. WI am reporting from the ground.

But maybe someone else will have some more ideas...?

Sure, here is the translation of the text from German to English:

'Micha'

mullemaus wrote:

RedR32 wrote: Why is it installed then? To avoid a dead end. A PD, just like a CR, operates without a fuel pump. The early PD models, for example, didn't have one at all. The actual fuel pump is the tandem or fuel pump 2 @ V277

.

I swear on a stack of pancakes that there will be (starting) problems in everyday operation if the internal tank pump fails. The suction pressure of the tandem pump on the cylinder head is not sufficient to draw fuel from the tank during starting. Therefore, an internal tank pump is a reliable solution.

Why is it installed then?

To avoid a dead end. A PD, just like a CR, operates without a fuel pump. The early PD models, for example, didn't have one at all.

The actual fuel pump is the tandem or fuel pump 2 @ V277 .

I swear on stone and bone that there are (start) problems in everyday operation if the internal tank pump fails. The suction pressure of the tandem pump on the cylinder head is not sufficient during starting to draw fuel from the tank. Therefore, the internal tank pump is a reliable solution.

I have 2 vehicles here without an internal fuel pump, one of which has had a defective internal fuel pump for about 2 years, and the customer finds the repair too expensive. They have all been running for years, both in summer and winter .




With the CR enabled, it would run (with reduced performance), but after being turned off, it would no longer start. Keyword: PWM control .

Quote:

I have 2 vehicles here without an in-tank fuel pump, one of which has had a defective in-tank pump for about 2 years, and the repair is too expensive for the customer. They have all been running for years, summer and winter. icon_wink.gif

I have some running too...

It only becomes problematic if the diesel engine creates steam bubbles in the supply line, or if the connector on the fuel level sensor allows air to enter.

Hi Micha!

Micha007 wrote:

... The ZK came with new valves from AMC. ...

Please create a 13/18/23 log for approximately 10 organ seconds and upload it here.
Have you reconfigured the PDUs for the new rack, or were they already installed?
The next step would inevitably be: measure the pressure at the tandem pump (i.e., get a pressure gauge!). There should already be 1 bar of pressure at the starting speed.

Generally speaking, errors are only recorded for components if the Main Software Test (MStG) is able to detect an error or implausibility in that component. For example, with the water temperature sensor, this is only possible during operation or during the engine starting process.
Regarding the NW sensor: Is this sensor (!!) also from the old head?

Best regards from Munich!

EDIT: AND PLEASE provide a complete vehicle scan with a full parts list!!

NW-Sensor: es ist der alte vom alten Kopf. Was heißt 'mit Geber'. Ich geh mal davon aus, das der G40 ein Hallgeber ist mit 3-pol. Cables!?

'We installed the new head gasket. We took our time and were very careful throughout the process. We replaced all three rubber rings and the valve lifter. Then, we pressed the head into the pre-oiled seat (I could clearly feel the stop), and secured it with new screws, tightening them to 3 Nm, plus 90 degrees, and then another 180 degrees.'

13/18/23 Log: I'm happy to do that.
Ich habe VCDS 10.?? (06 glaube) voll freigeschaltet/registriert, mach aber nicht jeden Tag solche Experimente. Und bevor ich die Batterie wieder leer sauge, würde ich es beim 1. Get it right.
Please describe the procedure for creating a log file again, briefly.

Maybe it will already work after the pre-wiring is updated!???

By "sender," I meant the counterpart to the NW sensor, or the sensor wheel located behind the NW wheel.
Has this been taken from the old one? If not: Please check if it's the correct part for THIS engine!!! If it was taken from the old cylinder head: Was anything bent or broken during installation?

Before we can help you with VCDS: Please enter your VCDS serial number in your profile .

Best regards from Munich!

The donor wheel has been taken from the old head.
Only the valves and bearing shells were replaced on the head (along with various screws, of course!). Nothing was bent, and the assembly can't be done incorrectly due to the groove on the shaft.

I will gladly provide the serial number tomorrow; I need the device to do so. Or, is the serial number already available in a scan or log from an earlier date?

Never mind, I found it, I'm going in now...
I hope you can give me some instructions, as I'd like to work on the car again tonight.