Elan S4(Strombergs) starts for a minute then fades

[stebbs]

The car is not a good starter but when it finally gets going, I can get it started (running rough) for less than a minute and it fades, no matter what I do to keep it going. I set static timing but it doesn't run long enough to set the timing accurately. I have had the Strombergs off and cleaned and the float chambers seem good. When I take them off they seem to be full of gas. Tested the mechanical fuel pump by disconnecting and watching the flow as the engine is turned over. Plenty of fuel delivered.
It feels like it should be fuel but I can't see how. I would welcome any ideas anyone has to get it running.

[gherlt]

And you checked the pipe from pump to Strombergs ?

[SENC]

Are you using the choke? With what impact? Mine needs to warm up a bit before it idles smoothly enough off-choke to not need soming revving.

In addition to choke, the "not a good starter" makes me think timing is still off. What do you mean by not a good starter?

[derek uk]

What are the diaphragms like? Holes or splits not always obvious.

[stebbs]

I check the pump to strombergs by turning the engine over after disconnecting the pipe and watch it fill up a jar. It only starts with the choke but still runs briefly when I push the choke in after a few seconds. I've had the strombergs out and cleaned them where I could, cleaning out the float chambers. Diaphragms are both good. I replaced one previously.
To give you more background, I bought the car 10 months ago and have run into many issues. At one time the exhaust camshaft snapped. I got a replacement and to the best of my knowledge it's installed correctly.
For unrelated reasons I had to take out the engine. When I put it back in it had had new valves and some paint work as well as some minor issues resolved. Now it's back together and I'm trying to get to the point where the engine is running long enough to adjust carb and timing settings. "Not a good starter" means it takes several tries (cranks) each time I try to start it but eventually it will burst into life, only to fade after less than a minute.

[SENC]

Will it keep running if you are revving? What rpms at idle (albeit rough)? Will it keep running with light throttle (what rpm)? Or does it peter out regardless of rpm/throttle?

[stebbs]

It doesn’t seem to matter if I use choke or not or what I do with the throttle it dies. That’s why I’ve recently been thinking it’s fuel starvation but I can’t see how it could be starving. So the answer is it Peters out regardless of what I do

[SENC]

Certainly strange if you're getting good, consistent flow from tank to pump based on your test.

A couple thoughts (if not already mentioned) - check to make sure you aren't losing vacuum somehwere - leak between intake manifold and 2ndary throttle, adaptor plate, carb or leak in/unconnected vacuum tube from manifold to lights, etc. If there isn't enough vacuum to pull fuel from the jet as the throttle opens or from the choke when the throttle is closed, I could see this result.

I'd also try a touch more advance on the dizzy than where you set it statically, just to see if that results in any improvement. On mine, there is a several degree range where starting and running is pretty healthy, but if just outside that range on the retarded side it does not want to catch or run. I'm sure you've done it, but I'd recheck resistance on the plug and coil wires - I know you're getting spark, but if one or more are weak that could contribute.

If those simple checks don't help, I'd take the carbs off again with close attention to fuel tee (if you still have the plastic please replace it now with a proper tee, but either way look at it for any restriction), the fuel intake on the carbs for restriction, fuel bowl floats (are they set properly, or too low and shutting the valve before enough fuel is in the bowls to feed the engine?), and intake valve/needle (did you replace these when you cleaned the carbs?). Also inspect the jets and needles to ensure there isn't anything in the jets/on the needles that could limit fuel flow.

[stebbs]

All sounds like good advice. I will take a look at all your suggestions. A lot of this is new to me so here are potential stupid questions.
Regarding the vacuum leak, how important the vacuum outlet is on the right/front that goes to the light opening mechanism? If there is a leak there or a hole in the chassis that it eventually plugs into how much will that affect the running.
There were no hoses on the vacuum from the carbs to the distributor when I bought the car but I added them. I assume they are correct as they go to the valve on the left/rear carb and then to the distributor. Should I just remove that when trying to resolve this issue? On removing anything I would assume blocking it to ensure there is no vacuum leak.
To adjust a touch more advance, is that clockwise or counter-clockwise on the rotation of the distributor?
In addition, I am trying to do this with the air filter off. There is a breathing tube from engine to filter that is obviously not in place without the filter. Is that a potential issue?
Thanks for your help

[derek uk]

If your light pods are opening normally there probably isn't a leak in the system. Nothing to stop you blanking it off for testing and the same goes for the vac pipe to the dizzy. It's not been mentioned that your advance retard mechanism might be stuck in the full advance condition so worth checking. As you have the filters off I would be tempted to try and keep the engine running with Easy Start. Can you keep it running long enough to see if the pistons lift correctly/equally when you blip the throttle? Yes I'm straw clutching but that's the way this is going.

Derek UK

[mbell]

There were no hoses on the vacuum from the carbs to the distributor when I bought the car but I added them. I assume they are correct as they go to the valve on the left/rear carb and then to the distributor. Should I just remove that when trying to resolve this issue? On removing anything I would assume blocking it to ensure there is no vacuum leak.

I don't think the car ever came with vacuum advanced/retard distributors from the factory. I would make sure to disconnect the vacuum signals, seal them and try again.

Getting a good vacuum signal on a twink is difficult and vacuum advance/retard could be really messing with your timing.

Given it doesn't sound to be an original distributor it might be good to post details on the distributor you are using. It may have been fitted due to lack of correct one.

[USA64]

My 69 S4 has a vacuum on the distributor. It connects to a (unobtainium) valve that works off the throttle stop (if I recall correctly) part of the emissions control. After a rebuild at Union Jack, I was told not to reconnect the vacuum.

[derek uk]

In case my comment was misunderstood I was talking about the mechanical system of weights and springs under the points plate. All sorts of things can go wrong there. Rust, broken springs, worn holes in the weights etc. If kept clean and lubed they are usually fine. I assume the Lucas unit does have lubrication points. I'm more familiar with Bosch units.

Derek UK

[SENC]

Agree with the above, and no harm plugging off the vacuum connections to test. Particularly agree with bypassing the vacuum advance mechanism on the dizzy and even grabbing a couple pictures and a number off the side of the distributor if you can. Eliminating unnecessary variables might help hone in on the root problem.

The distributor spins counter clockwise, so rotating the distributor clockwise will advance (bring the rotor to the connection sooner).

A few other thoughts - have you confirmed firing order on the plug wires is correct? You mentioned a cam change - did you get the cam timing/timing chain right? That is something someone else would need to help with as I haven't had to go there, yet.

[Elan 1600]

I had a similar problem on a weber engined car about 40 years ago. It turned out that there was a tiny air leak in the pipe between the fuel tank outlet and the main fuel pipe as it goes through the bodywork from the boot.

As this was the highest point between the tank and the fuel pump virtually no fuel leaked out, so there was no sign of the leak.

The air leaking in finally filled up the clear sight bowl on the fuel pump so the pump stopped picking up fuel.