I have a 1967 E Type OTS with which I am having a problem and I hope someone can offer some insight. This has happened twice recently.

Driving along, my fuel pump stops operating and I coast to the side of the road and wait for a tow home. The choke light also doesn't light but push the button and the engine cranks over so there is power going to the switch. I examine the fuses (OK) and check the wiring behind the dash (connections intact and tight). Close the dash, turn the ignition key (fuel pump hums), push the choke lever up (light goes on), push the starter button and the engine fires right up. I didn't do anything but look at it.

My first thought (other than that the fuel pump was on its way out) was that there was a bad ground but the choke light and the fuel pump are grounded separately so very unlikely that both grounds would simultaneously go bad. After the second time this occurred I did the same inspection but this time I also tested conductivity of the wires between the ignition switch and the fuses and across the fuses themselves. All seems well. I close the panel, go through the starting process and all works just as it should.

Of course, now I have little trust in the car.

I am wondering if there could be a problem within the key switch that causes it to break contact between the switch and the fuse block while still allowing power to pass thru the switch to the starter button.

Anybody have any similar experiences or any suggestions as to what the cause of problem might be? I'd appreciate any thoughts.

Thanks in advance.

 

How old is the fuel pump that you have? They do wear out and the symptoms are what you have. Yes, a bit on the pricey side, and if you have an SU, the newer version is electronic so no points to go bad. There are also after-market units if you're OK going that route.

https://mossmotors.com/377-255-solid...d?gad_source=1

Not hard to replace, make sure you get all new washers, and disconnect the battery before commencing the surgery.

 

Thanks for your input, Valerie.

I'm not sure how old the fuel pump is but it is a Holley unit I installed probably over 15 years ago - don't remember my reason for not using SU, probably their historic unreliably. If it was just the fuel pump going bad, why would the choke light not work? And they then both come back to life simultaneously?

That's what's got me puzzled....

 

Ok, above my pay grade! :-)

Not sure how the choke system plays with the Holleys. Standard E chokes are mechanical.. pull out the lever (or whatever depending on iteration). for the light to go out means there is something shorting perhaps? Again, I don't have the particulars on that install, but there are many others here who can dive in... M Frank???

 

I suspect your key switch. You said you didn’t do anything but you probably turned the key off and back on. That could be enough to get it to make contact. The are known to fail and it’s the only common place for power to the fuel pump and the choke light. The next time you have this problem, try just cycling the key on and off a few times. You could remove it and clean and tighten the connections on it. Or just replace it.

 

Yes, either to do with the switch (as above, turning it off and on will improve the contacts briefly) or the symptoms aren't related. In which case it could just be a lack of fuel at the carbs. That is, the fuel chambers run out because the supply is less than the amount being delivered but of course replenish when the engine is stopped and there is no drain on the fuel;. So, either the fuel pump isn't delivering enough fuel, or there is a blockage perhaps in the fuel filter restricting flow.
I suspect the former, check the switch thoroughly or just replace it.

 

Fuel filters were changed and carbs cleaned a couple of months ago so I don't think that the problem is the carbs running dry. And if it was, the pump would still be running and in a couple of minutes it should restart.

Thanks for reinforcing my suspicion re: the key switch. Yes, I did cycle it a few times during the process of investigation and suppose if the contacts were loose or or just dirty/corroded that could have allowed for short term connection. Wire connections to the switch were all tight. I don't know how the internal contacts are arranged but I guess it would be possible for one connection (to the starter button) to be good and the one next to it (to the fuel pump, via connection at the hot side of fuse 6) fail.

I much prefer an obvious problem (oh, look, this wire is just about broken off from the connector) to the invisible ones. Always feel more comfortable that I've actually solved it.

Guess I'll order a new switch and hope that solves the problem. Only time will tell....

Thanks again.

 

I had a similar issue on my 71 S3 recently. Jag would run well then start to lose power until I would have to pull over to the side of the road and wait awhile. It would then start and run for a while until the same thing happened and repeated. The awhile time became shorter and shorter (10 min, 5 min, 2 minutes ) until I couldn't make it around a short circle of a few blocks around my house. The Electric to fuel pump was ok and no other electrical issues were noted. Finally, a mechanic suspected the fuel pump or bad fuel line. However, due to the cost of a new fuel pump, he focused on the fuel line. The voltage to the pump was good but the fuel bowl wasn't filling up very fast. He decided to replace all the fuel lines and found some black gunk in the lines which he thought was the black silicon that had been used to seal the gasket on a new fuel tank. Silicon and gas don't go together well. After blowing out all the lines, and adding a fuel filter, the fuel bowl now filled up quickly as it should have. The car now purs like a kitten and runs great and I'm again one happy E Type owner. Hope this helps.

 

duplicate

 

Thanks for your input.
I purchased a new ignition switch (which other unrelated projects have gotten in the way of me installing - hopefully I can in the next couple of days) which has a much more definite "click" from off to on than the old, currently suspect unit does. I'm guessing that the original one is worn (who would imagine so, after only 57 years?) and that is the problem. So I am hoping the new switch will solve the problem and I'll get it installed this weekend.
Then, of course, I'll drive it bit wondering when it will crap out on me......

 

Yeah, keep us updated. Good luck!