Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Lazydocker]

Well... You must have managed to get further down the tank by now... How's it behaving?

[Kevin Wood]

Perhaps he's gone a little too far down the tank and is still pushing it along the A12.

Kevin

[feeutfo]

lag came back on the way back to Reading yesterday. Tank was about 1/3 full. Air temp was cooler too. Throttle pinned changing into third.... Berbump.

Only did it twice. Fine otherwise. I've filled it back up again now so i'll see what its like on the way to work at lunchtime and keep an eye on tank level when it occurs.

Other thought was to check vap pressure again. Wondered if colder air temp and hence retracting fuel volume and low fuel level would combine to affect vap pressure...? car reported 10°c when lag occured, sure thats much cooler than when it was set up on saterday.

[Kevin Wood]

I would check the vapour pressure under hard acceleration when tank is empty, then again in the same conditions after filling. The pressure in the tank will drop slightly with falling temperature and with falling level, but not as much as you might expect because, as the pressure drops, the remaining liquid will boil, bringing the pressure back up. A bit like a boiler in a steam engine.

Check the vapouriser temperature too. Maybe it's cooling off during a long period of cruising, reducing its effectiveness? :-/ Unlikely, as it has the full heater matrix flow through it.

Kevin

[feeutfo]

indeed, was hoping to try exactly that at some point during my last couple of visits to you, grumpy bullet took president at the time unfortunately. However on both occassions i managed to arrive at yours with a fairly full tank.

Trouble with calibrating on the road myself is i've no idea how that graph works, although i see your guide explanes matters, and i dont think Mrs G will drive it to the point that the issue shows up, bless.

[feeutfo]

should add its still better than its ever been, deffinately going in the right direction. Thanks guys.

[Kevin Wood]

indeed, was hoping to try exactly that at some point during my last couple of visits to you, grumpy bullet took president at the time unfortunately. However on both occassions i managed to arrive at yours with a fairly full tank.

Trouble with calibrating on the road myself is i've no idea how that graph works, although i see your guide explanes matters, and i dont think Mrs G will drive it to the point that the issue shows up, bless.

I'm always happy to sit in the passenger seat with a laptop.

Will give you a shout next time I'm over at the best Sunday lunch restaurant in Mortimer.

Kevin

[feeutfo]

indeed, was hoping to try exactly that at some point during my last couple of visits to you, grumpy bullet took president at the time unfortunately. However on both occassions i managed to arrive at yours with a fairly full tank.

Trouble with calibrating on the road myself is i've no idea how that graph works, although i see your guide explanes matters, and i dont think Mrs G will drive it to the point that the issue shows up, bless.

I'm always happy to sit in the passenger seat with a laptop.

Will give you a shout next time I'm over at the best Sunday lunch restaurant in Mortimer.

Kevin

wow, lunch as well...          

[TheBoy]

Are we still sure this issue is pressure related, or have we ruled that out.  Or are we unsure again

Odd that chrisgixer's seems to do it on low tank - is that what others are seeing?  Or is chrisgixer's a slightly different issue due to different tank setup that shows as a similar symptom to others?

I thought LD had nearly, almost cured his? Mine was (albeit briefly, and on a full tank) fine.

 :-/

[tunnie]

full tanks do help, when mine has blipped at high rpm, its when the tank has been low

[TheBoy]

full tanks do help, when mine has blipped at high rpm, its when the tank has been low

Your issues are less likely to be the same as V6 ones, as you don't need same flow.  I'd guess your poor vapouriser is more of a factor?

[Lazydocker]

TBH it's so intermittent I'm having issues pinning it down.

Still think it's the injectors though :-/ Although mine seems to be fine with a full tank and get worse or fine when nearly empty and plays up when full (depending when it was calibrated) :-/

[Kevin Wood]

The only mechanism by which the engine can "know" if the tank is full or empty, is by the vapour pressure.

It could be that the vapouriser output pressure under load is slightly dependant on tank level but I would expect that to be evident by looking at a trace showing all the vital signs. :-/

Kevin

[TheBoy]

TBH it's so intermittent I'm having issues pinning it down.

Still think it's the injectors though :-/ Although mine seems to be fine with a full tank and get worse or fine when nearly empty and plays up when full (depending when it was calibrated) :-/

What if you calibrate at half full?


Shouldn't the reducer maintain a constant(ish) pressure (within its capabilities) despite tank pressure?

[Lazydocker]

TBH it's so intermittent I'm having issues pinning it down.

Still think it's the injectors though :-/ Although mine seems to be fine with a full tank and get worse or fine when nearly empty and plays up when full (depending when it was calibrated) :-/

What if you calibrate at half full?


Shouldn't the reducer maintain a constant(ish) pressure (within its capabilities) despite tank pressure?

Thing is, the Vap pressure isn't dropping noticeably when the problem occurs :-/