1970 MGB Roadster
Discussion
Two problems at the moment, seeking some advice:
Starter: Single battery (new 525 cranking amps) 12v negative earth system. Turned key, click click click, dreaded solenoid click. Tried directly at the starter, same result (direct connection with cables and jumped the starter). In haste, just bought a new starter. Plugs out, new starter turned engine slow. Plugs in, starter didn't have the power to turn the engine over. I can turn the engine over at the crank easily by hand with plugs out and with moderate force plugs in, normal I suspect. Pulled battery out my truck to eliminate the battery as a variable, same result. Jumped directly at the starter to eliminate the cables, same result. Returned new starter, waiting on another new one. Do you think I just got a bad new starter or am I missing the issue?
Fuel pump: The guy that sold me the car put in an electronic fuel pump cube. There is only one wire running out of it. When I turn the key on, the pump just keeps on pumping, shouldn't this quit when it build pressure? I can see and feel the fuel lines at the carb are pressurized. Should this thing just keep running? I would think it should shut off when pressurized? Do I need new pump?
This car sat for a while, how long, I do not know. A few to several years I imagine.
Your input is greatly appreciated.
Starter: Single battery (new 525 cranking amps) 12v negative earth system. Turned key, click click click, dreaded solenoid click. Tried directly at the starter, same result (direct connection with cables and jumped the starter). In haste, just bought a new starter. Plugs out, new starter turned engine slow. Plugs in, starter didn't have the power to turn the engine over. I can turn the engine over at the crank easily by hand with plugs out and with moderate force plugs in, normal I suspect. Pulled battery out my truck to eliminate the battery as a variable, same result. Jumped directly at the starter to eliminate the cables, same result. Returned new starter, waiting on another new one. Do you think I just got a bad new starter or am I missing the issue?
Fuel pump: The guy that sold me the car put in an electronic fuel pump cube. There is only one wire running out of it. When I turn the key on, the pump just keeps on pumping, shouldn't this quit when it build pressure? I can see and feel the fuel lines at the carb are pressurized. Should this thing just keep running? I would think it should shut off when pressurized? Do I need new pump?
This car sat for a while, how long, I do not know. A few to several years I imagine.
Your input is greatly appreciated.
Morning.
The starter: check the earth straps, there are two i believe. There is one that runs from the battery and is usually bolted onto the battery carrier frame, and is very often neglected. If you can locate it, just unbolt it, give it all a clean up and re-attatch it. There is another earth strap bolted to the front nearside engine mount IIRC. The mount has rubber bobbins to deal with vibration, and the braided earth strap simply attaches to either side of the mount. Again, undo it, clean it up and re-attatch it.
And then isn't there another one, from the gearbox/bellhousing to the body adjacent to? Gawd, i should know but i have a bad memory.
The fuel pump. Don't know about this particular pump, but yes the fuel lines to the carbs should be presurised, and there are little needle valves in the tops of the float chambers (the round bits on the sides of the carbs) that shut the fuel supply off. Yes, the normal SU pump would stop operating when it senses the back pressure, but yours might not. Yours might have some sort of valving that means the pump itself continues operation but is not actually pumping fuel to the carbs, then allows fuel to flow when the level in the float chambers drops as fuel is used.
Should give you something to go on.
The starter: check the earth straps, there are two i believe. There is one that runs from the battery and is usually bolted onto the battery carrier frame, and is very often neglected. If you can locate it, just unbolt it, give it all a clean up and re-attatch it. There is another earth strap bolted to the front nearside engine mount IIRC. The mount has rubber bobbins to deal with vibration, and the braided earth strap simply attaches to either side of the mount. Again, undo it, clean it up and re-attatch it.
And then isn't there another one, from the gearbox/bellhousing to the body adjacent to? Gawd, i should know but i have a bad memory.
The fuel pump. Don't know about this particular pump, but yes the fuel lines to the carbs should be presurised, and there are little needle valves in the tops of the float chambers (the round bits on the sides of the carbs) that shut the fuel supply off. Yes, the normal SU pump would stop operating when it senses the back pressure, but yours might not. Yours might have some sort of valving that means the pump itself continues operation but is not actually pumping fuel to the carbs, then allows fuel to flow when the level in the float chambers drops as fuel is used.
Should give you something to go on.
As above earth strap, it is between the bellhousing and floorpan. The cause of 99% of MGB and Midget non turning over problems.
The fuel pump is totally normal, it is doing the same thing as an SU pump, only difference is SU pumps being a bellow design they physically can't pump once pressure is reached. Don't worry about it, but if you get sick of the noise fit an SU pump.
The fuel pump is totally normal, it is doing the same thing as an SU pump, only difference is SU pumps being a bellow design they physically can't pump once pressure is reached. Don't worry about it, but if you get sick of the noise fit an SU pump.
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