Running: Why You Die After 5 Minutes (Cold)

Hi!

My engine (1Z) is having some strange problems. Now that it's colder, it starts perfectly, but after about 5 minutes of running, the power slowly decreases until it completely shuts off. I suspect the problem is related to the fuel filter or the return valve. Has anyone else experienced something like this? If I manage to get past that initial warm-up period, everything works fine again. The filter is only 2 months old, but maybe there's a manufacturing defect? But if that's the case, it shouldn't run properly even when warm, right?

Hoping for your help, without a car, everything is useless!

Greetings,
Felix.

Hello there.

Maybe avoid using winter diesel? The filter/pump could get clogged until the fuel warms up. Would that be a possible solution?

The thought had crossed my mind as well, but I had already filled up my tank at Aral twice in the meantime! It really shouldn't be happening, especially since a colleague who also fills up there hasn't had any problems.
I took another look at the check valve; it's making a bit of a rattling noise, but it seems to be working.
Okay, here's the translation:

'Also, after I changed the filter, and it was still warm, I noticed a diesel smell. Then I saw that it was leaking from the return hose of the ESP (Exhaust Gas Recirculation system) near the return valve. This had never happened before! But at the time, I didn't think much of it, which is strange, isn't it? It seems like there's more resistance in the return flow, possibly due to the filter.'

Clubman wrote:

My suspicion lies in the area of the fuel filter/return valve.

Hi Felix,

Have you replaced the return valve along with the seal? If possible, check immediately after the engine stops to see if there are any air bubbles in the lines leading to the ESP. Also, check for air bubbles before a cold start!!!

Mileage (always specify!)?

Best regards, Christian.

Have you already drained the diesel filter?

Oops!
Oops, my mistake! I probably left the old O-ring in place during the last filter change, which I don't understand because it should have been clipped inside the filter, but it must have been stuck to the bracket. So there were two, which, as you know, is one too many .
This created an air gap, and when the cold diesel fuel didn't want to flow properly, it tried to get through with air instead.
But I would like to sincerely thank you all, and I will definitely remain loyal to this page!

Until the days...
Felix.