TDI Fuel Pump Problems: Troubleshooting Guide

Hello everyone,
I have a 1Z in my VW T3 bus, and my ESP (Electronic Stability Program) pump was leaking. Therefore, I wanted to replace it with a spare pump.
Unfortunately, I don't have an OT marking, so I did some digging.
I secured the timing belt to the pulleys with cable ties, keeping it under tension, and then replaced the pump.
I'm quite sure the belt hasn't slipped.
With the new ESP, the engine starts but misfires and has no power.

I then wanted to use the VAG diagnostic tool to check and adjust the fuel injection point.
Measurement value 2 in block 1 of the basic settings is always set to 255, regardless of how I adjust the pump.


What now?
I suppose I have to identify the OT (overtime) and do everything correctly this time.

How do I find the 1Z OT?

Best regards,

Lukas.

Hi,

Quote:

With the new ESP

new or washed with Perw... uh, EBOOK?

First, disconnect the KW (cooling water) from the OT (oil tank) and the NW (water) / pump... This has been discussed many times before and should be findable through the search function.

Best regards, Rainer.

Hi Lukas,
Stupid story, a motor without an OT marking , who messed that up?
Could you not have taken the flywheel and clutch from the JX model?
No matter... now you have to make your own OT marking.
You need to figure out a way to prevent piston 1 or 4 from reaching the top dead center (TDC) position.
I'm referring to a foreign object protruding into the combustion chamber and blocking the piston (the fuel injector or glow plug would be possible access points).
Then, rotate the engine until the piston hits the top, mark this position. Rotate the engine backward approximately 340 degrees until the piston hits the top again, mark this position. Place a measuring tape and mark the midpoint between the two reference marks as the Top Dead Center (TDC) mark.

And then, as always: Engine at TDC (Top Dead Center), place the ruler at the back of the camshaft, and adjust the injection pump so that the plunger is 0.55mm past TDC.

Best regards, Kurt.

Hello Kurt,

kuestenkuddel wrote:

You need to come up with something that prevents piston 1 or 4 from reaching the top dead center (TDC) position. I'm referring to a foreign object protruding into the combustion chamber and blocking the piston (the fuel injector or glow plug would be possible access points). Then you turn the engine until the piston hits that point,

set a mark, rotate it backward approximately 340 degrees until the piston hits again, } set a mark, attach a measuring tape, and mark the center of both auxiliary marks as TDC (Top Dead Center). }

"I prefer to use a manometer (pressure gauge) for this, as it's simpler and surprisingly accurate. Remove the old spark plug, insert a suitable tube, and seal it (using two-component adhesive). Insert the manometer into the fourth cylinder (it's easier to access than the first). Rotate the first or fourth cylinder close to Top Dead Center (TDC), fill the tube with liquid (oil, ink, etc.), and carefully rotate the engine. As the piston moves downwards, the liquid is drawn towards the engine; as it moves upwards, it's pushed out. At TDC, the liquid remains stationary. The thinner the tube, the more accurate the measurement."

Best regards, Uli.

Are the operating temperatures of 1 and 4 the same?
Or have I misunderstood something?
Regards,
Lukas.

weichsand wrote:

Are the OT values of 1 and 4 the same? Or have I misunderstood something?

It doesn't matter if you only want to mark the Top Dead Center (TDC) position. The pistons of cylinder 1 and cylinder 4 are always in the same position. However, cylinder 1 will then be in the compression stroke, while cylinder 4 will be in the intake stroke, or vice versa.

However, to properly calibrate the ESP, the "correct" OT (operating temperature) must be found, as it is no longer a matter of indifference.

Regards,
Jens.

Hi,

weichsand wrote:

Are the OT values of 1 and 4 the same?

Yes, for the 4-cylinder engine. The mark on the flywheel indicates the top dead center (TDC) for cylinder 1 and cylinder 4. The ESP (eccentric shaft position) or NW (needle valve) rotates only half as often as the crankshaft (KW), which is why there's a distinction between ignition TDC and overlap TDC. The crankshaft doesn't care about any of this, so you can use either cylinder 1 or cylinder 4 to mark the new position on the flywheel.

Best regards, Uli.

And how do I find the right occupational therapist?
Does it then depend on the camshaft and is determined by the ruler?

And I thought I understood... Now everything is all mixed up in my head again.




sorry


Lukas.

Oops.
Okay, one more time:
The top dead center (TDC) for cylinder 1 is at the ignition TDC.
Cylinder 4 is also at top dead center simultaneously, but with valve overlap.

One more rotation, and cylinder 4 fires at top dead center.
and at the same time, the 4th piston is at the top of its stroke, which corresponds to the valve overlap phase.

And you always see the marking at the top of the keyboard (keyboard).
The crankshaft rotates twice for every one rotation of the camshaft. Please examine the size of the timing belt pulleys.

That's against the rules now – no tutoring on basic knowledge.

Edit: threatening finger hovering over the minus sign .

Thank you.
arrived, I'm going to keep my mouth shut now .
Oh man, I was standing around doing nothing.
Best regards,
Lukas.