CDI: Air in Fuel Line?

I'm currently working on a C203 Avantgarde that belongs to a friend.

The car is giving me a hard time.

Does air directly enter the supply line right after the filter?

The O-rings and return lines are new and have been inspected.

I'm still not getting bubble-free diesel even before the filter.

Does anyone have any ideas?


For testing, I used a larger vacuum pump to draw diesel fuel from before the filter. I do this with a transparent hose!

While the engine is running, I see air bubbles in the hose leading to the pump, and then the car stops.

Best regards, efistho.

Edit: Now absolutely nothing is coming out anymore, even though the tank is a quarter full!

The 203 likely has a saddle tank, consisting of a left and right half. It's probable that fuel is no longer transferred between the two halves. Consequently, the surge tank, from which the pre-filter pump draws fuel, has been completely emptied.

I've also found that out now.

How are the two fuel tank halves connected?

Isn't the electric pump supposed to be in the tank?

Meanwhile, after charging the battery, even the starter motor isn't turning over anymore.

(I haven't made any major attempts to get started!)

However, is driving permission granted via a key?

I'm going to visit Daimler today and try to figure things out.

Best regards,

Hello!

I believe it's a jet pump. That means the amount of fuel being recirculated also helps to transfer fuel between the tank halves. There's nothing electrical involved in that process; only the priming should be electrically powered.
It has nothing to do with the starter not turning. People should just remember that a well-equipped C203 can draw up to 20 amps when the ignition is on, and significantly more during preheating.

There's actually a suction pump located between the two fuel tank halves.

The CDI does not have an electric pre-feed pump. The fuel is drawn directly from the front of the engine. There is virtually no pressure between the tank and the engine.

It's possible the starter motor is faulty; I'll check the voltage.

Unfortunately, I cannot translate that word because it does not appear to be a recognized word in the German language. It may be a misspelling or a made-up word. If you can provide more context or clarify the spelling, I would be happy to try again.