Won't start

[Farvie]

Car won't start, my new pump clicked very slowly, took fuel line off carb and turned it over and not fuel coming out, (not sure if it should or not) now fuel in the car is 6 years old and only been fired up this year, I removed the sender unit to make sure it had fuel and gauge was maybe wrong, but it does have plenty but not sure if somthing clogging it up, it was running fine once I put new pump on, but now it just not having it,
Fuel pipe is new, (6 years ago) would disconnecting fuel line and blowing air down the pipe help? Really not sure best thing to do.?

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[svenedin]

Fuel that is 6 years old will be completely stale and it won’t burn properly in an engine. It sounds like you have a blockage in the metal fuel pipe from tank to pump. Yes, blowing air down it is a good idea. You also need to drain all the old stale fuel. There is a drain plug at the bottom of the tank (on original tanks but some replacements don’t have one). It’s also possible that the filter in the pump has rapidly clogged up with debris. Check that too. Yes with ignition on and pipe taken off carb the pump should pump fuel.

Stephen

[geoberni]

Stephen has pretty much summed it up.
Fuel that is 6 years old is pretty difficult (near impossible) to use.
When disconnected from Carb, Pump should click fast and squirt fuel readily.
It only stops supplying fuel when the float chamber in the Carburettor cuts it off.

Assuming you have an SU Fuel Pump, check the filter, which is the Nut on the bottom, as fitted.
So you'll need to dismount it or remove completely, depending on the way it's been installed.
You may need to blow some air back down the line if it is blocked.

Red Arrow indicates where Filter is.
Yellow arrow indicating flexible pipe is usually a fixed copper pipe from tank. A Past owner fitted my car with a short flexi pipe .
.

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[Farvie]

Thanks for getting back guys, will drain old fuel out and check pump one, I did put some STP carb cleaner down it yesterday and do the hand over the carb thing while reving, hope this didn't cause the problem

[svenedin]

I doubt that was the issue. The engine can actually run on carb cleaner or certainly my lawnmower did when that had fuel problems. If you put your hand over the inlet you cut off the air to the engine.

[Bill_qaz]

Hand over intake and partially blocking it has similar effect to a butterfly choke and enriches the mixture, whereas the minor carb pulls the main jet to enrich the mixture for cold start.
Follow the others advice and get fresh fuel pumping to a container before reconnecting to the float chamber.
Take care not to spill fuel

[mowogg]

I would clean up the fuel pump points. This could well get the pump to run faster.

I find it SU pumps dry out from lack of use and they will not prime. I assume this is due to dry non return valves. I usually squirt a little wd40 down into the pump and they prime. I guess carb cleaner would do the same

[svenedin]

It’s a new pump I believe but stil Mowogg is right to say to clean the points. SU recommends this as the pumps often sit on the shelf for a long time before sale.

Stephen

[Farvie]

Will do all of the above, and report back

Thanks All

[mike1864]

Don't be tempted to use a vacuum cleaner to clear any part of a fuel system; pipes, tanks or devices.
Compressing Air + Fuel in the presence of a spark (electric motor) could create a jet engine!

[mike1864]

From recent experience, 18 month old fuel doesn't work. But 10 month old was OK (just).

[myoldjalopy]

If the supply to the pump is disconnected, it should clatter away furiously, thus indicating a blockage in the fuel line to the pump. If it doesn't run fast then the pump has a fault of some description. My car once stopped dead and it was a blocked fuel pipe - blowing back down the line cleared the blockage. As it was a little five gallon SII tank, I decided to fit a bigger capacity one which eliminated he risk of further blockages and meant I could go further on a full tank as well

[Farvie]

Fuel tank drained, pipes disconnected and blown air down fuel line into a container, didn't see anything in container apart from fuel, turned ignition on and no clicking, taken fuel pump off and cleaned point, but they looked fine anyway and pumps been reconditioned by the club, now I'm new to all this car stuff, the point are touching each other, is this correct? See pic

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[svenedin]

Yes that's correct. At rest the points are in contact completing an electrical circuit through the coil inside the body of the pump. When connected to power the coil is energised which makes in into an electromagnet. This pulls the diaphragm up and the points open, breaking the electrical contact. The diaphragm is pushed back down by a spring, the points close and the cycle repeats.

Connect the pump to power off the car and it should run rapidly. You will not hurt it with no fuel in it.

I am interested to see that the pump top pedestal appears to be made of a black 3-d printed plastic. The original are Bakelite and brittle.

Stephen

[Farvie]

Just tried that and getting very slow clicks I did a video but not sure if I can post in on here. I'll add pick of my pump you may see somthing I've done wrong.

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[svenedin]

Nothing wrong that I can see except perhaps the earth cable going to the body of the pump which looks rather tired.

Do you have a multimeter? If so I would like to know the quality of the earth connection to the pump i.e its resistance or at least that there is electrical continuity.

If you can test the pump by connecting the terminal at the top to one terminal of the battery and the terminal on the body of the pump to the other battery terminal. It should run fast. It does not matter which way round the polarity is. Then at least we know the pump is working normally.

Did you clean out the pump filter?

Stephen

[Bill_qaz]

The pump earth is the screw arrowed, give it clean and put a new wire to a good ground point or while testing go directly to the battery earth.If the red cable in picture is your battery earth, then remove it and thoroughly clean surface to bare metal and refit.

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[Farvie]

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Mine positive earth so can I run a wire from earth on pump to the - on battery?

[Farvie]

Just cleaned up all contact areas and all wires, still no fast clicks, tried putting wire on the earth's and still nothing.

[svenedin]

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Mine positive earth so can I run a wire from earth on pump to the - on battery?

Run wire from positive side of battery to the earth terminal on the side of the pump. Negative terminal to pump cap (you already have this connected via the wiring loom). This applies to POSITIVE earth just to be clear for anybody reading this in future.

Stephen