Gasa XM 2.1 "Prestige"

[Gasa]

..no, a friend of mine who deals with it, I used to be interested in painting cars, but I hate doing that business more.

[Dieselman]

^ I think that people interested in mechanical works usually are not good at/interested in bodywork, especially painting. They don't have the patience for it.

[Gasa]

...painting requires a lot of patience, removing parts, protecting, and smoothing out all the irregularities on the sheet metal, which is why I had a friend finish it all, that's his job.

[Gasa]

I had a problem with the engine yesterday, I haven't tried it on a long trip yet, but for now everything seems to be fine again.
I was driving to a place about 45 km from my city, about halfway there my engine stalled, it happened when I was changing gears so I thought I hadn't pressed the clutch in time and that's why the engine stalled.
While driving I turned the key and the engine started again, I got there without any problems, after two or three hours I drove back home, it started normally and after 5 minutes of driving the engine stalled again.
After that I tried to start it about 15 or 20 times, it starts for 2 seconds and then goes out, it doesn't take gas and I see that during those 2 seconds it emits a lot of black smoke, and the "check engine" light is on.
I waited about half an hour and tried to start it again, then it started up completely normally, it didn't emit black smoke, it took gas and the "Check engine" light didn't come on. It worked in place for about 10 minutes and I decided to head back home. While driving, I felt it chop 3-4 times, but since I was driving it at 120km/h, it kept going.
About 5 km to the end of the road, it turned off again, then something occurred to me to open the tank cap to see what would happen. When I unscrewed the cap, I heard air being sucked in, a vacuum was created in the tank, I screwed the cap back on, after two attempts to start the engine, I returned home without any problems. This morning it started up without any problems, and during the day it also turned off without any problems, it works fine as if nothing had happened, the "Check engine" light didn't come on.
I've read on various forums that this has happened to people on other, newer cars, that a vacuum is created in the tank and that they had problems with stopping and engine power. I'll see if I can check the tank ventilation hoses these days. I don't have diagnostics to check if there's something else at issue why the engine wouldn't start.

This is a bit of a long post, but maybe someone has had a similar problem, or if so, knows what could be the cause.

[Dieselman]

The fuel tank vacuum sounds plausible, as the original fault description is one of either insufficient fuel, or an air leak into the fuel system.

The sudden stoppages, lack of starting and black smoke are indicators of fuel starvation, or air.
your car us fitted with the Denso Epic fuel system, so it's possible the injector sensor is misbehaving, causing the system to shut down, or timing irregularities.

Member Polonez's thread might be useful to you as it has sensor values and the Denso Epic manual in there. viewtopic.php?f=5&t=10290

Denso Epic fuel system info download/file.php?id=9001

[Gasa]

..probably that was the problem, the vacuum in the tank, I didn't have time to drive it around town, but this morning I tried it again and it started on the first try and it works fine.

[Dieselman]

A certain way to test is to connect a vacuum gauge to the fuel pipe and observe any vacuum build up, as you drive.

I wonder if the sanding dust from the paint job has clogged the breather?

[Gasa]

I'll see in one of these days to remove the protection from the rear wheel and check the pipes for ventilation of the tank.
I read on some forums that they had similar problems on Reno Clio dci, Mazda 626, and even on Honda XL 1000 engines, that they had the same situations, engine shutdown or loss of power.
The person with the Mazda says that the easiest way to solve the problem was to drill the tank cap with a 3mm drill bit and that he drove without problems for the next 70,000 km until he sold the car.
I'm not going to drill the plug, but I'm going to check the tank ventilation hoses.

[Gasa]

..for now it works, it doesn't turn off, I've driven 600 km and it hasn't turned off, I checked the air hoses, I removed the protection on the rear wheel, on one of the hoses where a plastic valve is connected, by blowing into it I noticed that there was a difficult air flow, that hose goes towards the tank and I couldn't see where it connects, in the end I applied the easiest solution and drilled a hole in the tank lid with a 2mm drill bit , so now there is always air flow.

IMG_20241228_112943.jpg

[Dieselman]

Were you suffering any air leakage into the fuel pipes issue? I have one car that when sitting overnight draws air in. I have already spent quite some time tracking down air leakage points, I clearly need to keep looking.