Lupo 3L AYZ geht aus - Ideensammlung gezielte Fehlersuche | Posts 32+

Quote:

Yesterday evening, I replaced the supposedly new male connector with a new Bosch filter. During the initial start, I left the "Knackfrosch" bypass in place, and after no more bubbles appeared, I properly installed the also new "Knackfrosch" connector.

Did you perhaps install the fuel filter dry and, due to excessive force, damage the O-ring and/or the fuel filter itself? Mann filters are used in millions of vehicles and are generally very reliable.

The hose clamps on the "Knackfrosch" (presumably a product name) are not exactly ideal – hairline cracks quickly appear when they are tightened.

Hello,

Yes, I initially installed the new "Knackfrosch" (a type of fastener) without any lubricant. However, it could still be installed properly (it was a bit tight, but without excessive force).

However, it's likely that nothing broke due to the clamps, because this new, somewhat noisy filter is now fully installed along with the Bosch filter and is working properly.

"The filter had spring band clamps installed. Just to be safe, I bought new clamps on Monday - now, according to the part number, they are supplying hose clamp fasteners."

I noticed that hose clamps aren't very good when I was working on the connector for the clear hose. I ended up slightly crushing a fitting.

Bye.
peace

Hello,

The car has become a repeat offender – it runs out of fuel due to air bubbles, even with a full tank. When I finally made it to the gas station, about 27.5 liters went into the 34-liter tank. After 860 km, there were approximately 6.5 liters left. This is roughly the fuel level at which the problems occurred last time.

Since I had experimented with an external tank without any findings, I thought I could rule out any problems with the tank .
At least the tried-and-true trick of using a bypass helped get rid of the crackling sound again.

What would be the next logical step now?

Bye.
peace

Quote:

What would be a logical next step now?

If the problem "always" occurs at fuel level X, it's likely that he's drawing air into the tank, although it might only happen intermittently when the fuel level is around that critical point.
That's probably why it's also running with a bypass for the "Knackfrosch" (a type of valve or component).

because in a closed system, the air above the filter – as mentioned before – cannot escape back into the tank, and the filter is no longer being filled with "fresh" fuel.

I think you'll need to check the fuel tank.

Hello,

It took a while before I could do anything again. Last week, I ran out of gas again – with the tank about 1/4 full, even though I had already bypassed the fuel cutoff switch. Luckily, I had a 20-liter canister in the car, so it wasn't a major problem.

"Another (used) carburetor arrived today. I tested it by draining most of the fuel from the tank. I didn't see any air bubbles in the carburetor. The 25km ride home afterwards went smoothly. Let's see if the problem has been resolved."

There was an O-ring in the intake manifold that was a little stiff – at least compared to new O-rings, but it wasn't brittle or completely hard.

Bye.
peace