• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

MGB 1978 mg fuel smell

Share this page

M

MGMARTY

Freshman Member
Offline
HI Everyone, I am a proud new owner of a 78mgb . I am far from being a car guy and do my best to repair as much as i can. This MgB has lots of little issues (mainly electrical) so I thought I would start with fuel smell in the compartment.

1. After reading great stuff on here, I believe I have found the problem. In the trunk on the right side near tail light is a silver canister. I'm guessing it might be a charcoal filter although in the pictures attached I thought the filter was up front. Anyway. I discovered all the tubing has rotted and was broken off. Can you please tell me what the hosing configuration is. Am I right in thinking that hose goes from tank up to canister (either entry?) then from canister to the silver vapor line? BTW I connect a hose to the main silver line and was able to blow through the line, which I am guessing is a good sign that there is no obstruction unless I shouldn't be able to?

2. the black canisters in the front of the engine, Is one of those also another charcoal?

Thanks so much in advance.
Marty
 

Attachments

  • IMG_7361.jpg
    IMG_7361.jpg
    51.5 KB · Views: 325
  • IMG_7360.jpg
    IMG_7360.jpg
    46.3 KB · Views: 301
  • IMG_7359.jpg
    IMG_7359.jpg
    29.9 KB · Views: 341
  • IMG_7357.jpg
    IMG_7357.jpg
    45.8 KB · Views: 360
One in the boot is vapor. Black one in engine bay is charcoal canister.
Vapor hose top goes to charcoal canister and lower to gas tank.
 
Marty,
Welcome to the forum and congrats on your B! Youve gotten good advise and I would suggest a Bentley manual so you can learn more. Keep us posted on your progress!
Rut
 
Welcome, MARTY, and Grantura's post gives you the right info. The rear canister is a "condenser" of sorts, the lower port sends condensed vapors from the front mounted charcoal unit, condensing it back into the tank as liquid fuel. Renew all the 'perishable' (rubber) lines in the Evaporative Loss System and report back as to the result.

Use more effective Zebra or the spiral screw clamps like the one on your front charcoal canister to replace the factory ones on all connections as well. The original clamps are great for mass production, not so great as a long-term answer.

And the Bentley manual is an invaluable resource for info. Original "Factory Service Manual" and more.
 
Thank you everyone for your kind help. The vapor canister is all taken care of. Next the wiper jets are not working. I removed the lines to the waher pump and with a bit of priming the pump seems to be working. So I want to follow the lines. How do I access the line and I'm guessing the T connector? Do I have to go under the dashboard.? Are the jets themselves able to be removed?

Thanks you guys
Marty
 
Just to be clear, zebra clips are European or German style and have the best holding for your needs.
I would clear the nozzles with a small pin before going deeper into it...may have wax or other debris in the jet.
Sorry I forgot to welcome you earlier....happy motoring!!!!
 
Yup-yup. Straight pin to clear the nozzles. A '78 has too much "stuff" under-dash to make getting to those squirters an easy task. Likely you won't need to find out!
 
Hi everyone, just wanted to say thanks. Your help is priceless. So as I continue I have more questions.
1. I have attached a couple of pictures. my questions are as follows. There is a valve I'm guessing that is air or emissions related, should there be hoses coming off the little square valve. ?
2. The refillable container in the second picture, what is that used for? I stuck my finger in and it is pretty empty...do I need to fill?
3. Rad fan - is it normal for the fan to kick on a lot? Pretty much everytime I drive it comes on. Especially when I turn off the car. I checked coolant level in overflow when the car was cold and all levels were normal.

I haven't even begun to discuss the cold start issues....and idling issues...next post :smile: one step at a time.

Thanks so much everyone for your help
marty
 

Attachments

  • container.jpg
    container.jpg
    40.9 KB · Views: 322
  • valve.jpg
    valve.jpg
    43.9 KB · Views: 362
Yes, it needs to be topped up with the correct fluid. Use Castro LMA.
Fan will kick in and out as needed. Be sure that the Otter switch on the top tank is safety wired, as they tend to work their way out. Not sure about the smog equipment, as your car is too new for me.
Get on flea bay and purchase a shop manual quickly!
Good luck.
 
Square item with hose ports is for your vacuum advance. It should have hoses connected.
Just notice you are in Cali....do you need to smog the car????
 
If your clutch master cylinder reservoir was that low you should probably inspect the slave cylinder and the clutch hose. That fluid had to go somewhere....

That piece with the hose connections on the side of the pedal box is part of the original TCSA (Transmission Controlled Spark Advance) system. Originally, the vacuum advance hose from the distributor would connect to one side and another hose from there to the intake. There is (or, at least, was) also a switch on the transmission that closed only when the transmission was in 4th gear. That switch energized the one pictured to allow vacuum to the distributor when in 4th gear, but not any other gear.

Those are often disconnected or missing, but you'll probably need it to get through inspection in CA. Sorry.....
 
Thanks Joe. Also what are your thoughts on these:
1. starting cold is difficult....it catches and if i apply gas it stalls. I have to do the super quick tap tap tap on the gas peddle to finally catch but once it's going for a minute its fine.
2. idling is all over the place sometimes its high up in 1800 to 2000 then its right down to 500 almost on verge of stalling out and i have to give it some gas. This happens even when the car is warm. thanks
 
MGMARTY said:
Thanks Joe. Also what are your thoughts on these:
1. starting cold is difficult....it catches and if i apply gas it stalls. I have to do the super quick tap tap tap on the gas peddle to finally catch but once it's going for a minute its fine.
2. idling is all over the place sometimes its high up in 1800 to 2000 then its right down to 500 almost on verge of stalling out and i have to give it some gas. This happens even when the car is warm. thanks
Click to expand...

my '76 was a California car though all the smog stuff is long gone.

1. I believe you have a Zenith Stromberg carb. These had an automatic choke. It consists of a spring like coil that expanded and set the choke. Most often these are broken. A manual choke is much easier.

2. The ZS carb is really set up to have all the smog gear working and is not steady without. It also doesn't like anything but the factory air cleaner. It may also need to be rebuilt.

3. On the Midget the carb actually had vacuum retard rather than advance. I was advised to disconnect and block the vacuum line.

I also switched to an SU carb but this might not be an option for you.
 
Hey John, thanks. yes I have a ZS carb and problem is I know nothing about cars. just trying to learn I suspect I'm going to have to take it into a mechanic. YIKES!! Sadly I still have to pass emissions in California and this was an Illinois care so perhaps it's been modified. would replaceing the carb be the best choice and could I possibly do it via instructional video?
thanks
 
First of all, you can do this. These are simple cars. And not hard to work on.

there are two manuals you need.

Bentley

https://www.ebay.com/itm/MGB-SHOP-M...104984&hash=item338c0a7d3a:g:eEkAAOSwZA1aTnvN

and Haynes

https://www.ebay.com/itm/Repair-Man...867992&hash=item3f7a4b752f:g:VjkAAOSwYLRbnkvD

they are complimentary. You should get Bentley cheaper but I might be delusional too as it has been awhile since I bought mine.

the carb rebuild kits are cheap and logical. Also, are you a member of a club? If not you may want to find one - there is typically much help and support and others who will have had to get their cars smogged also.

keep posting questions - we are keen to help.
 
There are kits available to eliminate that poxy automatic choke with a manual one. A worthwhile task.

The Bentley manual comes in two editions, be sure to get the one covering the later cars.

The idle issue could be a few things. Sticking throttle cable or linkage, weak throttle return spring or perhaps an air leak at the carb mounting. Some water in a spray bottle, spray water around the joints where the carb meets the intake and see if the idle changes (drops) momentarily. Though I'd suspect linkage issues to be more likely.

From the description, if this came into our shop a "step one" would be; carb off, complete rebuild with manual choke conversion and new intake gaskets. That eliminates a whole bunch of possible issues. The Zed-S units were a concession to emissions standards, giving fits to owners and technicians alike. JP's suggestion to find an owners' club is a good one, you're likely to find more knowledgeable, experienced folks there than a local repair shop.
 
Back
Top