15 replies to this topic

[Nev]

This guide explains how to eliminate and rationalise the fuel vapour system that sits above the O/S ear. To do this you need to take the clam off. It looks like a worrying job, but is really very easy indeed and the completed job is very simple for the eye to verify.

 

 

TIME REQUIRED

30 minutes (though you may need several hours to take you clam off).

 

 

TOOLS + PARTS

A couple of screwdrivers, a knife and a couple of 10mm spanners/sockets to undo the retaining fixtures for the carbon canister. No extra parts need to be bought.

 

 

BEFORE STATE

A = 18mm I/D hose, joins fuel filler neck to vapour exchange (E).

B = 8mm I/D hose, joins roll-over valve © to carbon canister (D)

C = Roll-over valve, allows vapour transit when upright, blocks vapour transit when inverted.

D = Carbon canister.

E = Vapour exchange box (for want of a better term).

F = 3-way joiner with 3 * 8mm hoses off it.

G = 18mm I/D hose that comes up from the tank.

H = 8mm I/D hose that comes up from the tank.

J = 8mm I/D hose that comes up from the tank.

K = 8mm I/D hose, leads from carbon canister to solenoid.

L = Hard pipe that leads from solenoid to inlet manifold (not shown in the pics).

 

 

 

PROCESS

1. Remove and scrap D.

2. Remove and scrap E.

3. Remove and scrap A.

4. Remove and scrap L.

5. Remove and scrap K.

6. Remove and scrap L.

7. Remove and scrap F (and it's 3 short hoses).

7. Keep hose B, feed it down from C to your wheel arch area to vent fuel vapour, maybe extend it.

8. Connect G to the fuel filler neck.

9. Connect H to the bottom of the roll-over valve ©.

10. Now double check all jubilee clips and joints are done up firmly.

11. Maybe fit a gauze filter onto the end of hose B, though in practice I doubt this is vital.

 

 

AFTER STATE

You will be left with 3 pipes coming up from the tank:

 

1. Hose G, which needs to be attached to the fuel filler neck.

2. Hose J, which needs to be terminated/blocked. I used an 8mm bolt with a non-threaded shank.

3. Hose H, which leads from the tank to the bottom of the roll-over valve ©.

 

 

This setup leaves the tank able to vent excess pressure and retains the safety of the roll-over valve just in case you invert the car. The weight saving of the removed parts is about 1.2 Kg. Your car is no longer Euro 4 compliant.

 

Edited by Nev, 12 July 2019 - 07:11 AM.

[pete-r]

Useful.

The solenoid in mine ticks like a bugger since the SC went in.

[aquilaproejct]

Strap the solenoid to the engine mount bracket (engine side) with some cable ties and hey presto the chattering solenoid will not be heard in the cabin anymore.😀

[FLD]

Should the output from the roll over solenoid ( B ) go to the inlet side of the engine (pre TB)? This way fuel vapours go into the engine and the fuel tank is protected by the air filter?

IIRC there was a car that caught fire several years ago from the fuel vapours around the engine after getting rid of this lot. Terminating that pipe to the inlet should hopefully solve that.

[Nev]

Should the output from the roll over solenoid ( B ) go to the inlet side of the engine (pre TB)? This way fuel vapours go into the engine and the fuel tank is protected by the air filter?

IIRC there was a car that caught fire several years ago from the fuel vapours around the engine after getting rid of this lot. Terminating that pipe to the inlet should hopefully solve that.

 

That would be theoretically safer in terms of vapour fumes, as it would retain the closed circuit, though Simon on here says with this same config he gets no smell of petrol at any time.

 

On a boosted car however, you have to be sure there is a 1-way valve (that works!) between the inlet side and the roll-over valve, otherwise you will be boosting your fuel tank (which could easily burst)!! Even if the one-way valve does work, at idle the engine will be creating a strong vacuum in the fuel tank (which could even conceviably crush it). Also as the pressure changes in the tank it may affect idle and give some weird idling effects. This is why I vent to atmos at the moment.

 

Before Euro 4 (which is why this fuel vapour contration was installed), hundreds of millions of cars used to vent to atmos...
 

Edited by Nev, 12 July 2019 - 11:25 AM.

[Nev]

IIRC there was a car that caught fire several years ago from the fuel vapours around the engine after getting rid of this lot. Terminating that pipe to the inlet should hopefully solve that.

 

Who's car was that please? Do you happen to know if his setup exactly the same as what I've described above? I wonder what the circumstances were, immediately after fulling his tank? I wonder if he did the fixings securely so there was no leaks etc.

 

It's hard to imagine how that happened really, if you vent out to the wheel arch there are no naked flames there and very easy for fumes to blow away in the wind. Any pressure changes in the tank will only be minimal and surely only vent a couple of CC of fumes per minute.
 

Edited by Nev, 12 July 2019 - 11:30 AM.

[FLD]

It's a vague memory from somewhere... I'll see if search works.

Putting the pipe into the filter would solve the pressure issues.

[Nev]

It's a vague memory from somewhere... I'll see if search works.

 

Yea, I remember it too, it's one of the reasons I've put this mod off for years. However, I suspect he must have done something wrong/stupidly as I can't see how my config would catch fire TBH.

 

Simon Boyde on here has the same config as this and he's done a few track days and road driving with this setup fine for a year or so.

Edited by Nev, 12 July 2019 - 11:46 AM.

[FLD]

Have done some minor googling it does appear to be rather vague. I can find two such fires but neither were identified as this cause. Apologies for being a doubter!

[Nev]

A little update. I've done a few miles in the car and had it sat in a hot garage and not noticed any fuel vapour smells at all.

[ditonics]

My baby has all the fuel crap removed and has done for a while. On an after market ECU the solenoid is dead weight anyway.

 

My car lives in a garage that is more like a conservatory (its hot) and I don't suffer with fuel vapour smell.

 

Nice write up Nev, glad you took the plunge

[Nev]

Jeeze, just re-read this, my engine bay is a bit dusty!

[Dean_H]

What if you piped J into H using F rather than blanking it up?

[Rosssco]

What if you piped J into H using F rather than blanking it up?

 
I 'think' both F and J are just vents from different parts of the tank, but you only need one vent working (going through the roll over valve). In that case, there would be no reason why you couldn't connect them in a Y..

 

I could be wrong so I'll let someone else answer definitively!

[Zoobeef]

What if you piped J into H using F rather than blanking it up?

 

Yep thats what I did.

[Nev]

Yep, you could Y them together (but there would not be any functional benefit), hence why I blanked off J - quicker, cheaper and just as good.