Don't worry. By construction, you can drive _normally_ with the cap off and the fuel will not get out.

Hi Alex,

if we assume that the judering is caused by the vacuum, why it happened then only higher ambient temperatures?
Do you have an idea?

Higher ambient temperatures could mean lower atmospheric pressure which would mean the pump would have to work harder to open the valve? Just a thought.

At higher temperatures the fuel and vapour in the tank would expand so the vacuum would form much quicker? No Longer the owner of a 2013MY Fuji White GS

"Fiat Lux" a philosophy not a car

Certainly hope I haven't thrown a red herring in there with the fuel cap thing but it certainly sorted me and it would kind of make sense that a vacuum may momentarily starve the engine of fuel. FL2 TD4 GS 60 reg Facelift - so many issues
2019 DS. Terribly unreliable.
Sold DS for a 2021 Mitsubishi Outlander PHEV. Fingers crossed....
Sold Outlander for a 2014 SD4 SE Tech because I’m mental
Now greatly regret selling the Outlander. MPG of the FL2 is atrocious and so are the fuel bills. Fun though 😎
Couldn’t afford the fuel bills so back to an older Mitsubishi Outlander PHEV. Significantly better than I remembered it to be…

Chuck - I don't think so - the symptoms are the same as those discussed in the separate long topic about things to do with fuel caps and vacuums:
http://www.freel2.com/forum/topic20985.html
Perhaps the two threads should be merged (this is on the Customer Relations Forum after all ) No Longer the owner of a 2013MY Fuji White GS

"Fiat Lux" a philosophy not a car

So it is Westville I never look at the sections the posts are in!

Would be magic if this was such a simple fix. Think Dan could be getting quite a few orders.... FL2 TD4 GS 60 reg Facelift - so many issues
2019 DS. Terribly unreliable.
Sold DS for a 2021 Mitsubishi Outlander PHEV. Fingers crossed....
Sold Outlander for a 2014 SD4 SE Tech because I’m mental
Now greatly regret selling the Outlander. MPG of the FL2 is atrocious and so are the fuel bills. Fun though 😎
Couldn’t afford the fuel bills so back to an older Mitsubishi Outlander PHEV. Significantly better than I remembered it to be…

I looked at merging them, it may become unreadable as it merges in date order, much better if people searched first and create a new thread only if it's nedeed

Hi,

i have done a little bit brainstorming.
please let me know if it is possible or not. (am no car mechanic, please do not laugh )

We have two fuel pumps, one in the tank and one for the rail pressure at the engine.
There is vacuum in the tank, so the tank pump can not supply enough fuel to the high pressure pump.
At this situation a vacuum will be produced in the fuel hose.
Caused by the vacuum air can intrude into the fuel system (at connectors etc.)

This fuel/air mixture will arrive the engine. Based on the kind of air (moist or dry) the engine starts juddering.


Is it nonsense or possible?

Am I not right in saying that the pump in tank is for maintaining fuel delivery when off roading 2014 SE Loire Blue SD4 Auto (MY15)
Gone - 2011 GS Baltic Blue, Retrofit Electric Leather, Side Steps, 19"SC's, Roof Rails, TT Sat Nav Mod, Retrofit Premium Audio, Retro fit 2013 Xenons with DRL & Sig Strip (Clutch at 47k)
Gone - 2007 GS Narvik Black, Privacy Glass, 19" SC's, Side Steps,Roof Rails, Roof Spoiler, Lamp Guards, Retrofit Electric Leather (Clutch at 115k)
Gone - 2007 SE Santorini Black (Clutch at 120k)
BT IID (best money ever spent on a car)

Please don't merge threads, this is trying to find a solution to a strange situations.

As for the pumps...
There are 3 pumps.
- the one in the tank, electrical, for equalizing the two sides of the saddle type fuel tank.
- the lift pump or low pressure fuel pump, on the same body with the high pressure pump, mechanical, used to "suck" fuel from the tank and deliver it to the HP pump
- the high pressure fuel pump, mechanical, which rises the pressure for the fuel rail.

alex_pescaru wrote:

Please don't merge threads, this is trying to find a solution to a strange situations.

As for the pumps...
There are 3 pumps.
- the one in the tank, electrical, for equalizing the two sides of the saddle type fuel tank.
- the lift pump or low pressure fuel pump, on the same body with the high pressure pump, mechanical, used to "suck" fuel from the tank and deliver it to the HP pump
- the high pressure fuel pump, mechanical, which rises the pressure for the fuel rail.

They are right...

Chuckalicious wrote:

Certainly hope I haven't thrown a red herring in there with the fuel cap thing but it certainly sorted me and it would kind of make sense that a vacuum may momentarily starve the engine of fuel.

↑↑↑↑↑↑↑

What he said.

My hesitation was fixed with a SW update - Yes, Alex, according to the Update this should not work, but it did, my car went to the dealers 3 times, and this immediately fixed it, in my case.
It may be worth noting I have a "pre release" MY 13 car on a VX12 plate.

Around town, I really hate the auto box on all the FL2's I have driven, though they are a much better drive in town when set to S

Off road, Auto rules - given no low range