Moss Motors, Ltd

The ignition key on my '77 B gets hot to the touch. I don't remember it doing this previously. Is it something to be concerned about? I've had other cars with the same problem, such as my wife's 2006 MPV, but this is MY baby!

zach

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Happiness is an MGB!

Zack..without even looking at the schematics yet..my initial thought is, that it is connecting a ground circuit that should otherwise be handled by your ignition switch.

With the ignition on (doen't matter if the car is running or not), put an voltmeter between the key and the battery ground terminal. Then move to the battery positve terminal. Let me kow the readings for both, I'll check your schematic, and all will be right with the world once again!

 

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On their death bed, nobody ever said, "Gee I wish I'd spent more time at work!"

Could also be less than proper continuity in the switch, didrty contacts or such. This internal resistance would cause the switch to heat up and transfer heat to the key.

 

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Bayless
Never express yourself more clearly than you can think
'48 Prefect
'67 Sprite (project)

Yes, I agree with enfomeister, and THAT is actually more likley.

Do you have and funky circuits? That is to say, dim lights or slow wiper motor etcetera? These maladies would indicate a resistive (poor) connection in the switch.

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On their death bed, nobody ever said, "Gee I wish I'd spent more time at work!"

Hmmmm! Funny you should mention slow wipers. But this problem seems to be intermittent. Four days ago when this first happened, the key was mucho warm to the touch, and that went on for two days. Two days ago, it quit and the key is cool to the touch. Go figure. I will look into it, but first I need to replace a fuel pump. I was out running some errands today, turned a corner and hesitate, hesitate, dead. She just died under an overpass. There is no fuel to the carburetor - clear fuel filter - and no sound from the pump. There is power to the pump, so I assume it is just a dead pump. More later.

zach

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Happiness is an MGB!

Check the ground connection to the pump.  Have you tried hitting the pump?

Hi, Kimberly.

Tried hitting the pump to no avail. As I was talking to Geico about a tow, a good samaritan stopped to see if he could help. Turns out he also owns a '77 MGB and offered suggestions such as fuses, hitting the pump, etc. The only thing I have not tried is checking the ground under the car. It'll probably be Monday before I get around to it, if then. It's supposed to rain the next four or five days and the car is sitting in the street in front of my temporary quarters; I'm in the process of moving from Kentucky. But I will check that ground wire. I'll need to get a floor jack and jack stands; I think someone at work might let me borrow his. And if the ground wire is okay, what next? I saw one thread that mentioned sanding down the points, but if they are that bad, and if sanding them down works, is it only a temporary fix? And by the way, how do you get to the points to sand them? That's a lot of questions, but then it sounds like you have some experience with these cars.

Thanks,

zach

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Happiness is an MGB!

A bad chassis ground would not result in a hot key. Your problem is most assuredly in the ignition switch, causing electrical failure and the excessive heat.

Do the headlights work? Their circuit bypasses the ignition switch, although your fuel pump circuit does not!

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On their death bed, nobody ever said, "Gee I wish I'd spent more time at work!"

As you can see from my picture, my '67 is no longer running but in the process of resurrection. I had trouble with the fuel pump quitting back in the 70's.  Filing the points took care of it, and then wrapping electrical tape around the pump to seal off the crack where moisture can get in helped delay repeat offenses.  I did eventually install an after-market electronic pump.  Never had trouble after that. 

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Crisis doesn't necessarily make character, but it certainly does reveal it.

All systems are working except for the fuel pump. I checked the ground connection in the trunk (boot?) and it's good. Tomorrow, I'm going to ask around to see if I can borrow a floor jack and stand (mine are back in Kentucky), check the pump from underneath and, if warranted, get into changing this pump out.

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Happiness is an MGB!

I've come across several threads suggesting cleaning the contact points. Do you need to pull the pump in order to get to them?

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Happiness is an MGB!

Zach, I thought you said there was no power to the pump. Have you checked the hot wire for 12 volts at the pump? It should be a white wire but may not look all that white anymore. With the key on, you should have close to 12 volts there. If not then you have a problem with the wire or still the ignition switch. Depending on the year, the wire could also go to a connector on the solenoid or fuse block although it is not fused. You could have dirty connections there too.

Also, it's not hard to clean the contacks but you do need to remove the pump and do it on the bench. SU recommends using just a card drawn between the contacts rather than sanding them. Be careful not to damage the mechanics of the thing as it is easy to mess it up. There is a plastic cover at the end of the long cylindrical part that covers the contacts. It's also a good idea to thoroughly clean the filter while in there. It's at the other end. In fact, the recommended practice is to service the pump this way every 12,000 miles. Failure to perform at least some preventive maintenance is the reason most of us have so many problems with these pumps. If the pump is bad, Moss sells an electronic version that is reported to be problem free.

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Bayless
Never express yourself more clearly than you can think
'48 Prefect
'67 Sprite (project)

There is power to the pump. In fact, I just happened to have a meter in the trunk at the time and that was one of the first things I checked. I'm pretty sure the pump is dead, and I will try to get it pulled off tomorrow and check out the points, etc.. More updates to follow.

zach

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Happiness is an MGB!

Sounds like you're on the right track then. Remember to be a little careful with those contacts. Good luck.

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Bayless
Never express yourself more clearly than you can think
'48 Prefect
'67 Sprite (project)

Zach - See the article, Fuel Delivery Troubleshooting Guide in the SU Fuel Pump Articles section of my web site at: http://homepages.donobi.net/sufuelpumps/  To clean the points, remove the end cover and then loosen the screw that holds the upper points blade in place.  Scrub the points on fine sharpening stone or a piece of 400 grit sand paper that is on a god flat surface.  To gain access to the lower points, remove the pedestal mounting screws and carefully fold the pedestal back around the pivot pin that holds the lower points toggle in place until the points are exposed.  Use the sharpening stone or some sand paper on a flat piece of metal to clean the points down to bright shiny metal.  Reassemble the pump and reinstall.  Forget about cleaning any filter, the pumps for the later MGBs don't have a filter that can be accessed from outside the pump.  They have a small filter screen that resides under the inlet valve and is only accessible by disassembling the pump further than you really want to.

Cheers,
Dave 

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Cheers,
Dave
http://homepages.donobi.net/sufuelpumps/