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MGB MGB Fuel backing up into charcoal canister

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R6MGS

R6MGS

Yoda
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After getting the brake issues fixed with one mgb the next one to be taken out of storage is having a fuel issue. The pump seems to continuously run, flooding the carb and backing fuel up through the breather line into the charcoal canister thing over on the passenger side. The car will run, but fuel leaks out of that canister quite rapidly. I figured the float in the carb is gummed up and not cutting it's supply of fuel off when it's suppose too. but I thought I'd ask here and see what everyone else thinks before I get too involved.

Thanks.
 
That's th' first thing wot popped into my mind. Needle valves in th' float chambers. Get a set of Viton tipped ones and be done wifit.
 
Yep, in the carbs...they're not allowing the system to pressurize & the obnly place the extra gas can go is from the carbs to the cannister.
 
First of all , DO NOT blow the gas out of the charcoal canister with compressed air. Somewhere out west a tech lost use of one hand this way. (It exploded) At least that is what we were told at the British Leyland dealer.

Second, I'm amazed that there is an MG out there that still has a sealed evaporative loss system. It'll take that fuel separator/condenser a while to handle the overload.

Alan T
 
AlanT said:
Second, I'm amazed that there is an MG out there that still has a sealed evaporative loss system. It'll take that fuel separator/condenser a while to handle the overload.

Alan T
Click to expand...

I've got one that still has everything in tact & working properly.
 
Thanks for confirming my suspicions, the carb is now out on my bench ready for a rebuild tommorow.
Both of our MGB's have most if not all of the pollution stuff still on and working...course neither one has seen more than maybe 100 miles each since the early 90's, nor have they been worked on by anyone other than myself since then.
 
tony barnhill said:
AlanT said:
Second, I'm amazed that there is an MG out there that still has a sealed evaporative loss system. It'll take that fuel separator/condenser a while to handle the overload.

Alan T
Click to expand...

I've got one that still has everything in tact & working properly.
Click to expand...

So do I. :smile:
 
Scott_Hower said:
tony barnhill said:
AlanT said:
Second, I'm amazed that there is an MG out there that still has a sealed evaporative loss system. It'll take that fuel separator/condenser a while to handle the overload.

Alan T
Click to expand...

I've got one that still has everything in tact & working properly.
Click to expand...

So do I. :smile:
Click to expand...

Me, too! We are amazing people :jester:
 
Uh me too. Not a bad safety factor since the gas could spew onto your headers and start a fire. My'67 has pipes that drain down right near the exhaust.
 
That's simply British "incentive" to keep th' thing in proper nick, Vince! :devilgrin:
 
My 1974 GT still has everything in place and working properly. Always hear the 'click' of the anti run-on valve resetting as I walk away. But it still has the same gas smell as it did when new. Almost every invoice from the dealer has this noted.
Alan T
 
DrEntropy said:
That's simply British "incentive" to keep th' thing in proper nick, Vince! :devilgrin:
Click to expand...

Right - Incentive to drive faster for that sportier feel with the hopes that the added wind through the engine bay will extinguish the flames.
 
Well, with the freshened up carb back on it still continues to do the same thing. I blocked the fuel line with my thumb and the fuel pump does stop...so that isolates my problem to the carb again I guess. I took it back off and noticed the second(smaller) brass tube that goes into the fuel bowl was very difficult to blow through, I have now taken it apart again and cleaned out that passage really good so I am hoping that will do it. But does anyone have any other suggestions I should check while I have the carb off.

BTW: I had double checked that the floats are not sinking, and thhe needle is moving freely.
 
Have you checked the pressure of your fuel pump? Also, look carefully at the line beween the carbs and the cannister for leaks...any lost pressure it this area of the system will allow gas into the line and some ends up in the canister with very little effort.
 
Sorry for the delayed feedback....Since cleaning the vent passage to the fuel bowl it's been fine.....Well with this issue at least, today I found out moss sent me the wrong lower rad hose so the car is being held up again.
 
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