Datsun Roadster Forum-311s.org

Take the valve cover off and crank it over. If the valves are opening and closing, the cam is turning.

You might try removing the pump, and then place a small wooden dowel in the hole, on top of the halfshaft/camshaft and have a helper either turn the crank with a wrench, or spin with the starter briefly to crank the engine and see if the dowel teeter-totters up and down. If so, it's likely not the shaft offset. You're likely sucking in air from somewhere along the line. maybe a pinhole or rust hole on one of the metal lines? One other thought, can you hook up the lines from the tank, and manually pump the pump and see if you get any fuel from the tank?

May sound silly, but make sure your intake and output fuel lines are the same as before and not reversed. I have not had a mechanical pump for years, but I do recall that being a possibility. Also, just to be sure it's fuel related, try getting the engine to fire on starter fluid... won't run long but it will confirm that it would with enough fuel.

Go electric. But if you still want to try a 3rd pump I have a spare here in Pasadena. Also Carter makes a great tried /true 4070 electric that works great. 8 years and zero problems, nice constant flow I run as puller. By the way when you activate pump arm and put your tongue to it does it pull vacuum? If diaphragm is working it should.

The only (likely) way the fuel pump lobe would not be turning is if the lower timing chain broke or the jackshaft broke- both are possible but fairly rare.

Take off the distributor cap and crank over the engine. Is the rotor turning? If so the jackshaft and chain are intact.

Did you try running it on starting fluid or putting gas in the carb bowls? Still sounds like the pump is starving unless that rotor isnt turning. Fuel pumps dont draw very well in general. J

For sh*(s and giggles:

Suggest you go through this thread, isolate all the suggestions that have been made and make a list,

e.g.
1) blow through fuel line from pump to tank - done!!
2) try starting with starter fluid - done!!

etc. - this might help people help you, without having to read through all the posts

Sysrematic approachnwill win.
Disconnect input line from filter at pump. Can you pull fuel thru filter? A cheap Harbor Freight vacuum bleeder setup is very helpful here.
If you can pull fuel thru the filer and infeed line to carb, tahe the pump out of the picture by connecting the in and out lines at the pump and pul.ing fuel to the tee at the carbs.
If you get fuel at the tee, you know its the pump.
If you approach it systematically, you can isolate a component at a time and find the problem. No guesswork!
Dan

I would take the tops off the fuel bowls and cut 2 new gaskets that you traced on gasket paper. They can be ugly.
Check to see if there is gas in the fuel bowls, add some.
Take the floats out , if brass, and shake them to see if you hear anything. You want good floats so if cracked or with any sound, replace.
Replace bowl tops and tighten.
Try to start.
You are priming the system and if it runs you know that nothing else is the problem except the pump or filter, or plugging or vacuum leaks at hose clamps etc.
Good luck!
Linda

I missed that this was an SRL. Take the distributor cap off and crank the engine - if the rotor turns, the jack shaft is not broken.

While it certainly seems to be a fuel issue, I've seen nothing mentioned about electrical. I would, first ascertain that I indeed have spark to the plugs, and if so I would try to start it with some starting fluid (just don't go overboard) to see if that will pull some gas through the lines. If no luck there, I would then try to see if I could use a mirror to observe the fuel pump eccentric on the jack shaft while a helper turns the engine over. It is possible, though highly unlikely, that you could have a broken or worn jack shaft. Let's hope not! And good luck.

Missed Sid's post, observing the distributor would be much easier than using a mirror for checking for a broken jack shaft!

UPDATE 3
The car lives!

I removed the pump again (for what felt like the 30th time) and tried to pump it manually. I noticed it looked like there was SOME gas movement in the filter. For shits and giggles, i reversed the lines going into and out of the pump, even though i was SURE they were in the right orientation...and manually pumped again...the filter filled up in roughly 2 pumps. Goddamnit.
I was sure i followed the same fuel line path that was on the previous pump...because the length of the lines really only fit in that orientation. I was also sure that i attempted to swap the direction of the lines last week as a "might as well try everything" move to no avail...oh well.
It's running now, and running well...and that's all that matters.

Thank you ALL for your recommendations and support. I really appreciate it.

Congratulations! The best problems are the ones that are solved!

It's a pisser, isn't it, when our oopses are public.

but the cool thing is that we have all made them in one way or another.

glad all sorted

best

pete

Glad you found it.
Dan