Fuel pump

[Barry20383]

I am having problems starting my Javelin. Have had the same problem before am suspecting the mech fuel pump. On turning the engine over for a long period the plugs are dry no flooding. Have removed the pipe from pump to carbs and pumped by hand and seems a good flow. Could the engine not be pumping as someone mentioned the engine uses a different lever to the hand one. Will have to open one of the float chambers see if it is full. Spark and timing seems ok but no response from engine. Have ordered a fuel pump service kit from JCS hope this cures the problem.
Thanks for any info. Barry.

[Keith Clements]

Simply take one of the banjos off a carb and turn the engine over. If that does not squirt fuel , pump by hand. If that does not squirt, take off top cover of pump. Check diaphragm and valves are not stuck.
Note the engine should start if petrol primed by hand.
Also read this

viewtopic.php?p=43128#p43128

[Nick Webster]

What you do not say is whether the engine eventually starts after turning over for a long time.

I have had a problem with my Javelin (and other make classics) where, after returning to the car even after a short period, say, over night, the fuel bowl is empty. As a consequence I have been obliged to churn over the engine for longer than I would like before it starts. The answer is quite contrary to all the fears about the effects of modern petrol left in carbs. The problem is that the bowls are vented to atmosphere and the modern volatile petrol readily evaporates away while the engine is not running. The engine will not start without the correct level in the float bowls and it takes a while to fill them.

It is true that the hand priming lever and the engine push rod are not actually connected inside the pump but both act on one diaphragm so if the pump pumps from the priming lever then it should work by the engine. One slight difference is that as far as I am aware the movement of the diaphragm is less by the engine and hence it takes slightly longer to pump up the same amount of fuel. The supply is quite adequate though. I wiill leave out all the circumstances where thhe pump causes difficulty and a running engine stops.

To get round the problem I make a habit of using the priming lever before trying to start the car. You can hear the petrol filling the bowls. To avoid dirty cuffs etc I have now rigged up a bowden cable to the pump priming lever so that I do not have to put my arm down into the bowels of the engine. Jupiter owners may point to the advantages of electric pumps which can pump merrily away on their own and in effect disguise the problem exprienced by cars with mechanical pumps. Over the years I have had several bad experiences with electric pumps and just don't like them.

Next time you try and start the car, pump the priming lever first. You will feel a change in the lever when the carb bowls are full. It should then start straight away.

Nick

[Barry20383]

Have put 2 gallons of fresh fuel in and pumped by hand until pressure relief is felt then turned the engine over for long periods but no response from the engine. Taken the plugs out and they are completely dry. I could turn the engine over for a while then remove one float chamber to see if its full and also try closing the inlet valve pumping then letting go of the valve to see if there is pressure.
Will try first using a piece of pipe to check the head of pressure. I have had this problem since i had the car seems ages when cranking to get fuel through to start perhaps this is normal with a Jowett.

[Barry20383]

Have tested the fuel pump as mentioned before with a length of plastic pipe. The pump pumped the fuel up to the recommended 29 inches i tried it twice on turning the engine over and once by hand all reached the 29 inches so assume the pump is ok.
Will now have to look further as this is happening regularly and cant trust the car to go out. Have checked the spark and static timing and compression is 140 psi on all cylinders but engine is dead.
Had this a few times and engine bursts in to life suddenly then starts ok and runs for a few weeks then dead again.

[Tony Fearn]

Hello Barry.
I'm from the Pre-war Clan, but have a 1933 'Flying Fox' which on occasions doesn't want to start.
I don't use it often, and I've found that tickling the distributor points, after making sure they have the correct gap, with some very fine carburundum paper refreshes them, especially if they're wiped with carb cleaner afterwards.
This might not have any bearing on your problem, but it works for me.
Also re-new the wire from the coil to the dizzy if it looks dodgy.
Tony.

[Keith Clements]

I had a similar symptom on the Javelin last week. The car would cut out, just like fuel starvation. Found the wire between points and input terminal had broken. Car would be OK for miles!
I suspect that the vacuum advance exacerbated the problem.

[Barry20383]

Still having problems checked the float chambers these were full but turning the engine for a long period the plugs were dry. After double checking timing spark ect i resorted to spraying quick start down the carb inlets this time the car started and ticked over. I checked the suction on the inlets with a flow meter both showed 7 and seemed good suction.
Thanks Barry.

[Keith Clements]

I hope you are using the choke when trying to start.

When it is ticking over check with a tube in your ear all around the carb for bad gasket seal.