MGB Fuel guage '78 MGB

[clyderedmond]

As unlikely as it seems I have absolutely no idea of where to begin to check my now inoperable fuel guage. All was well until I took the old girl out for a spin yesterday. I noticed at once that the reading was on empty. I drove to the filling station to top it off since fuel theft is always a possibility. Having eliminated that, I am now ready to do some work but thought it might be prudent to ask the order in which one should check these things out. Any help would be appreciated.
Thanks,
Mike

 

[rick_ingram]

First place to look is on the sending unit's electrical connections. Make sure that they are clean and tight. The sending unit is located on the side of the tank itself, on the right side of the car. You can check all connections without removing the unit from the tank.

 

[bob67bgt]

Most of the time it will be at the sending unit. I would remove the green wire from the sender and touch it to ground with the key on. Have someone else look at the guage . If it starts to move then its at the tank. With a full tank zero your trip odometer and run abotut 200 miles. Then jack the car up from the right side and remove the sender.Jacking up from the right side will move the remaining fuel from the sender unit side. The float may have sprung a leak or the sender went bad. Also be sure the ground wire is attached to the sender if your year has one. Thats where i would start. Also gas eats black top pavement! Do this job with a bucket ready in case you get great mileage and fuel still runs out after the 200 miles. Bob

 

[clyderedmond]

Thanks, Rick. I had thought to start there, but wanted to be sure and go in logical order.
Cheers,
Mike

 

[clyderedmond]

I checked the wire out - only one brown wire into the sending unit. A bit of corrosion on the copper, so I tried to clean it off and no joy. Well it's too hot to deal with this now so I'll wait for Monday.....Thanks for the suggestions.

*****

Some hours later...tried again and we are all set. Thanks for the help-. I guess some die-electric grease is in order.

 

[WA1KWA]

Does the temp gauge work?

Colin

 

[clyderedmond]

Yes, the temperature guage works fine. The problem was corrosion at the contact at the sending unit. Cleaned it up and all is working fine again.

 

[WA1KWA]

Great news.

Colin

 

[rick_ingram]

Yes, the temperature guage works fine. The problem was corrosion at the contact at the sending unit. Cleaned it up and all is working fine again.

WooHoo! An inexpensive fix!

:thumbsup: