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1969 Fuel pump woes

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58Custom

58Custom

Jedi Warrior
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My MkIII has had an intermittent problem where once in a while it stops running. A moment later it starts and off we go. It sounds like it starves for fuel.

Well, I drove into work this morning over Little Tujunga Canyon where my speeds are lower and there are no other cars around me. Suddenly, the problem occurred. Because of my semi-seclusion I could concentrate on listening as I restarted.

So, the car stumbled to a stop. I turned off the ignition and radio and turned on the flashers. Then I turned on the ignition and clearly heard the factory electric fuel pump click rapidly as it filled the carb float bowls. I know that sound, as I hear it every time I reinstall the carbs after some carb work. I turn the key, she starts and off we go.

As I pulled around the last corner and aimed toward my usual parking spot she died again. I coasted to a stop and repeated the above process. Same noise.

Okay, so I assume that the fuel is being interrupted in it's journey from tank to carb. I suspect a failing fuel pump, but I seek the advice of the experienced in this fine forum. What say ye?
 
I would suspect something blocking the line, maybe in the tank. Time for a cleaning of the system.
 
jlaird said:
I would suspect something blocking the line, maybe in the tank. Time for a cleaning of the system.
Click to expand...

Good idea. Drop the tank, look out below!
 
Sarastro said:
Also check the wiring for loose, corroded, or broken connections. Not all problems are complicated.
Click to expand...

Yeah. Wiring is quite good on this one, but I have not checked it at the pump.
 
If you wish to double check the wireing drop a new hot lead all the way to the rear from the battery, add a switch where it goes through the cockpit. Also make sure the ground is solid.
 
jlaird said:
If you wish to double check the wireing drop a new hot lead all the way to the rear from the battery, add a switch where it goes through the cockpit. Also make sure the ground is solid.
Click to expand...

You, Sir, are conversing with the master of the test lead! I have built entire vacuum tube guitar amp circuits with test leads just to test theories. This fuel problem does have the feel of temporary blockage, though. I don't relish dropping the tank, just because it's a PITA to do it, but we all know that's the only way to be sure. And, of course, there will be more room to get into a position to check that pump wiring.

I did want to query the group in case the symptoms were an obvious indicator of a familiar pump failure mode. Sometimes parts have well-known personality traits, y'know?
 
Boy do I ever know Tom.
 
Also check the gas cap, if the vent is clogged, it will starve for gas.
A quick test is to pop off the cap the next time it stalls, if you hear a swoosh, get a new cap or slice the gasket inside the cap.
 
Or, cover the gas filler with a peice of tin foil, use a rubber band to hold it tight and poke a small hole in it so it can vent.

If the prob goes away you win.
 
spritenut said:
Also check the gas cap, if the vent is clogged, it will starve for gas.
A quick test is to pop off the cap the next time it stalls, if you hear a swoosh, get a new cap or slice the gasket inside the cap.
Click to expand...

Cap is old, seal is flattened. It vents like a mutha, especially when the tank is full, ifyaknowhatImean. The drive home this afternoon was worry free, even in the heat. I'm guessing foreign matter in the tank. Temp was climbing as I reached the first peak, but the downhill cooled the engine down. Those Youtube carb tuning vids were a great help. Critter runs real nice now.

Here is a webpage about the road travelled.
Little Tujunga Road
 
Great, caps are cheep, have Tony get you one from Moss.
 
I had a similar problem on my MGB-GT earlier this summer. Random fuel interruptions. I checked the fuel cap vent, the fuel filter, electrical connections, etc. Finally realized that the fuel pump clicking was getting louder and louder, but the fuel flow was getting slower and slower, until finally it quit altogether (in my garage and not on the road, thankfully). I replaced the Carter pump with a Lucas electronic (pricey! but looks original) and have not had a problem since.
 
sswarin said:
I had a similar problem on my MGB-GT earlier this summer. Random fuel interruptions. I checked the fuel cap vent, the fuel filter, electrical connections, etc. Finally realized that the fuel pump clicking was getting louder and louder, but the fuel flow was getting slower and slower, until finally it quit altogether (in my garage and not on the road, thankfully). I replaced the Carter pump with a Lucas electronic (pricey! but looks original) and have not had a problem since.
Click to expand...

OK, that brings up a new question the answer to which I will file for future reference, should disaster strike. For the 1969 Midget, if the original fuel pump fails does the forum think it preferable to obtain an exact replacement or is there a preferred aftermarket substitute?
 
I used to drive around with a hammer in the 73 to give the floor a whack to jolt the pump when the points would stick until I was able to replace them. Of course that was when I first got the car in the early 80's and didn't know where to get parts.
 
Boy you just opened a huge can of worms.
In my case I had no fuel line's at all so started from scratch bulid I went with the Facet 4PSI solinoid pump.

If I had all the orignial or OEM lines in I would replace it with the factory style pump.
Its quick and clean job heck it worked this long.....
 
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