MGB & GT Forum

So I've got a '78 that has been desmogged and converted to the Weber before I got it. As I've been going through cleaning it up and tuning it up it has a constant light oil/gas smell when running. After cleaning the caked on oil of the block and a new valve cover gasket I'm down to a mostly gas, minimal burnt oily smell.
Looking at all the systems this weekend I noticed the valve cover vent it just open to air, the tank vent line is in the U-shape but open to the engine bay, and both charcoal canisters are missing. The mounts are still there though near the firewall. So my questions are:

1) Since it doesn't cost power and can possibly kill the gas smell, putting the charcoal canister back is a good idea?
2) Since it's a Weber can I get away with only putting in only 1 canister to the valve cover, the fuel tank vent and the underside of the Weber? Or do I need to put in both canisters? From what I read on various threads the Weber doesn't need to use the ARO valve (which isn't hooked to anything), and I've had no issues with it dieseling since I bought it?
3) Anything else I haven't thought of putting the evap system back into working order?

Thanks y'all.

1) yes it is a very good idea.
2) I don't think the Weber has anything to do with this question. The charcoal canister will provide a 'filtered' air inlet to the crankcase, (a good thing) along with fuel vapors from the fuel tank. (another good thing)
3) Ensure you have the correct expansion tank installed in the boot. Ensure the hoses in the boot are not perforated etc. Re-install a non vented fuel cap. Cap the un used nipple on the charcoal canister

B

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Life's most persistent and urgent question is, "What are you doing for others?"

Since mine is still stock, what I found with all of the emissions junk still installed is that as Riley pointed out, the canister in the "trunk" (I'm an American) near the right rear side marker light has an intake and outlet hose that tend to crack. If they leak, the gas smell is intense.........but if all of yours are missing, that may be useless information. De-smogging mine (after the smog test) involved just removing the air pump and air rail, plugging the holes, gulp valve and it's vacuum line removed and plugged and advancing the timing. The charcoal canister, ARO and EGR valve stayed because they have no effect on performance.



Edited 2 time(s). Last edit at 2018-03-19 04:13 PM by Vern.

I apologize if I offended anyone by calling it a "trunk". But to me, "boots, bonnets, hoods and dizzies" remind me too much of California (from which I am a refugee).



Edited 1 time(s). Last edit at 2018-03-19 04:37 PM by Vern.

So this is the view inside my trunk. Looking at that moss diagram, the separator that should be back there, isn't? So is if that line runs right up to the open u shaped hose were the canister should be that's contributing to my gas smell? Plus it doesn't look like the separator is available from moss.

Yep, your expansion tank is missing, look like the PO ran a hose from the fuel tank vent to the outside of the car through that hose. That can give you a fuel smell... look for a tank on the Buy, Sell & Trade forum. Install it and the charcoal canisters... others will chime in on how it's done with a Weber carb.

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USMC 1967 - Always ... Semper Fi
79 RB Lowered, HS4s by Dave Braun & "Schlemmerized" 25D Dizzy, 9.5:1 CR, Mild Performance Cam, 18V with OD Tranny.
78 Midget MK IV Pagent Blue
73 GT in Black Tulip.. Engine by Hap Waldrop, OD Transmission by Dick Moritz Distributor is "Schlemmerized"
72 Midget MKIII Red

Mike
Good grief! Yes, some one thought they were smarter than they are.
You can see the support bracket still in place for this expansion tank, fastened to the body side trim strip fastener..

The expansion tank is fastened to a tang at the wing seam, (look up) you will see a hole to fasten the can to. The other corner of the can fastens to this support you still have.

Make sure your hard line going forward to the engine bay is clear and not clogged from 'whatever'.

These expansion tank are always available on eBay for not a lot of money. There is two different models, one has threaded hose barbs, (below) and the other just straight barbs for hose & clamps. You want the latter type.

B

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Life's most persistent and urgent question is, "What are you doing for others?"

Do you want me to send you one?

Here's a '79. Just tubing fittings off of the tank, goes to steel tubing, across the top of the trunk and then loops back and down under the car to the canister closest to the driver's side. My tubing is green because it's what I had in the toolbox when I found the cracked ones. Maybe this'll help.

So Warren sent me an expansion tank (thank you again), it's currently wrinkling after a good blasting and VHT spraying. I'm trying to tackle the charcoal canister. Ordered from Moss, came from China, no chance of it fitting! Anyone order one lately?
First it's plastic welded shut so no chance of maintenance, but then it's too big! After a 30m fight i got it into the strap in the mount, but then it won't sit down enough because it's caught against the angle of the frame from the washer tank. Tried it in the other slot, mine was made for 2 canisters, and it sits down far enough to get the strap around the body but the strap ends are a good 2" apart. That's not right, is it?
Buy the right parts and lose an afternoon to find it won't work pisses me off. I don't have that kinda time to waste.

Mike
Bad news sorry to read this ...................
You would be best to peruse eBay for these sort of things. MGB, Midget, and many other Brit cars of this era all used a similar canister. Some of these will even be sold with hoses etc. Way cheaper and will be original equipment that has a 99.9% chance to fit. At worst you spend another 1.99$ for new charcoal at the pet store.

Good luck

B

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Life's most persistent and urgent question is, "What are you doing for others?"