Electric fuel pump conversion for 1256 engine.

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Re: Electric fuel pump conversion for 1256 engine.

Postby thomas » Sun Dec 03, 2017 7:11 pm

Other thoughts after reading and agreeing with all the above advice:

I'm wondering still if petrol is being delivered up to the pump.
With the car on level ground, especially not facing uphill, with a gallon or two in the tank, it should flow by gravity alone to the same height fuel as the fuel in the tank, if you point the feed pipe entering the pump towards the ground it should start to siphon out, if it doesn't there's a problem somewhere before the pump.
You might try adding some more fuel to help it prime or manouevre the car such that it is facing downhill.
I'm perhaps wrongly regarding the small amount of fuel that came out the pump from manual activation as an anomaly.
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Re: Electric fuel pump conversion for 1256 engine.

Postby tynelord1969 » Sun Dec 10, 2017 6:49 pm

ADRIAN wrote:When fitting the pump, put the spacer on the pump with a gasket either side all smeared with thin coat of Hermitite or Hylomar sealant equivalent. Put the operating arm into the hole at the very top of the hole, and once the assembly is up against the block push the body of the pump downwards in order to line up the two bolts in their holes then tighten them up with spanner whilst holding the pump with the other hand to stop it moving. Can be a bit fiddly and difficult but it ensures the arm goes onto and stays on top of the cam where it is supposed to be, Fit petrol pipes onto the feed side of the pump only, then, with ignition wires disconnected at solenoid for safety, operate the starter. The pump should eventually pump up, squirt petrol out with force like a fountain, not a dribble . If it doesn't squirt, - the pump is faulty.
Another thought to check, If the pump you have is the incorrect type, in other words for another car, like for instance a Triumph Herald pump, the operating arm will be at the wrong angle. Only a slight difference in the angle of the arm will mean that it wont pump fuel, as the arm will be pushed more sideways by the camshaft lobe rather than lifted up as it should be on a Viva engine.


Thanks for the advice Adrian. I've been trying again to re-fit the new mechanical pump all afternoon, with no success. I primed the fuel line from the tank with one of those rubber pumps so I knew that fuel was in the feed pipe, before re-connecting to the fuel pump. I also looked inside at the camshaft using a mirror but nothing looked worn ( the camshaft didn't feel like it had a worn groove in it either when I stuck my finger inside).

Again when I was trying to position the pump I could hear the diaphragm moving as the activating arm pressed against the camshaft, but no fuel was coming through when I turned on the ignition.

However, reading your last message again, I see that you said to fit the heat insulator block to the pump and then fit the pump+insulator to the engine . My insulator looks fused to the engine block, so I would need to tap it off I suppose. Could this be the reason why my activating arm is not in the correct position, although I can't see how it would make any difference fitting the pump onto the engine+ insulator or fitting pump+ insulator to the engine, but I suppose normally when the cars were assembled then the insulator wouldn't be stuck to the engine block prior to the pump being fitted?
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Re: Electric fuel pump conversion for 1256 engine.

Postby thomas » Sun Dec 10, 2017 8:39 pm

I would disregard my post of Dec. 3rd, as I was thinking of the HB where the tank outlet is on the the forward lower left side of the tank, and the fuel is normally sitting just down the feed pipe an inch or two below the height of the pump inlet, so the pump on the HB doesn't really have to work that hard. I gather - from pictures posted, I haven't seen an HC in the metal since the 1980s - that it differs if that the fuel take-off is from the top of the tank.

This is a real mystery. Other than the propensity for in-line filters if fitted anywhere to block completely with mush and need replacing, there's not very much else can go wrong, I don't imagine the camshaft can float around much longditudinally such that the pump arm is missing the (quite narrow) operating lobe altogether and falling to the side?

I'm out of ideas but following this closely.
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Re: Electric fuel pump conversion for 1256 engine.

Postby tynelord1969 » Mon Dec 11, 2017 9:53 am

thomas wrote:I would disregard my post of Dec. 3rd, as I was thinking of the HB where the tank outlet is on the the forward lower left side of the tank, and the fuel is normally sitting just down the feed pipe an inch or two below the height of the pump inlet, so the pump on the HB doesn't really have to work that hard. I gather - from pictures posted, I haven't seen an HC in the metal since the 1980s - that it differs if that the fuel take-off is from the top of the tank.

This is a real mystery. Other than the propensity for in-line filters if fitted anywhere to block completely with mush and need replacing, there's not very much else can go wrong, I don't imagine the camshaft can float around much longditudinally such that the pump arm is missing the (quite narrow) operating lobe altogether and falling to the side?

I'm out of ideas but following this closely.


Thanks , any other suggestions are greatly received!
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Re: Electric fuel pump conversion for 1256 engine.

Postby thomas » Mon Dec 11, 2017 1:19 pm

Quick off the wall one then, though the information may be in other posts: Is the camshaft turning, can you see the rocker arms move up and down through the oil filler hole when cranking it over, does the distributor rotor turn?
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Re: Electric fuel pump conversion for 1256 engine.

Postby tynelord1969 » Tue Dec 12, 2017 9:37 am

thomas wrote:Quick off the wall one then, though the information may be in other posts: Is the camshaft turning, can you see the rocker arms move up and down through the oil filler hole when cranking it over, does the distributor rotor turn?


Thanks for the suggestion. I will have to get someone to turn the engine over on the starter and I'll look inside the fuel pump hole on the engine to see if the camshaft is turning. It's got to be something inside the engine as the new fuel pump is exactly the same as an old one which was replaced a few years ago ie the non serviceable sealed pumps, with the same code stamped on the activating arms. The fuel was coming through the fuel pipe from the tank as I've used a rubber priming pump to check. Fuel even comes through when I connect the new pump to the feed pipe and work the arm by hand. I can't see any fuel leaks along the pipework and I've tightened all the clamps. Mind you when I last tried to prime the fuel line with a rubber priming pump nothing came through so it looks like that's gone faulty too ( I put the feed end in a jar of petrol and still nothing pumped out the other end , so I'll have to return it to Halfords!).
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Re: Electric fuel pump conversion for 1256 engine.

Postby tynelord1969 » Sat Dec 16, 2017 10:53 am

tynelord1969 wrote:
thomas wrote:Quick off the wall one then, though the information may be in other posts: Is the camshaft turning, can you see the rocker arms move up and down through the oil filler hole when cranking it over, does the distributor rotor turn?


Thanks for the suggestion. I will have to get someone to turn the engine over on the starter and I'll look inside the fuel pump hole on the engine to see if the camshaft is turning. It's got to be something inside the engine as the new fuel pump is exactly the same as an old one which was replaced a few years ago ie the non serviceable sealed pumps, with the same code stamped on the activating arms. The fuel was coming through the fuel pipe from the tank as I've used a rubber priming pump to check. Fuel even comes through when I connect the new pump to the feed pipe and work the arm by hand. I can't see any fuel leaks along the pipework and I've tightened all the clamps. Mind you when I last tried to prime the fuel line with a rubber priming pump nothing came through so it looks like that's gone faulty too ( I put the feed end in a jar of petrol and still nothing pumped out the other end , so I'll have to return it to Halfords!).


Well I got a friend to turn over the engine and I could see the camshaft turning. I noticed that the cam is oval shaped so I wonder if you need to have the cam in a particular position for the pump's activating arm to sit on top of it? I've tried turning the engine using a spanner on the pully wheel but it's hard to tell what position the cam is in when you are turning it so slowly. Do you think this could be the problem ; the cam is out of position for the activating arm?
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Re: Electric fuel pump conversion for 1256 engine.

Postby tynelord1969 » Sat Dec 16, 2017 11:04 am

ADRIAN wrote:The standard mechanical pumps are perfectly fine if they are fitted correctly. Firstly, you must ensure the operating arm sits on TOP of the camshaft inside the hole in the block. If mounted underneath the cam, the pump will only operate at the lowest point of the stroke (only about 10% of the stroke). Secondly, all the rubber hoses attached along the fuel lines, rubber must be new and supple and the hose clips well tightened. If the hoses are old and hard and the hose clamps are not gripping tight enough, the pump will just suck in air and wont pump up the fuel.
Adrian

Hi Adrian. I took your advice and bought some Hyolmar non setting gasket seal to attach the paper gasket and the new insulator block to the fuel pump. I slotted the nuts through the holes to keep the spacer aligned , but so the nuts didn't poke right through, so I could position the pump's arm at the top of the engine hole and then slide it downwards to align the nuts. I could feel the arm making contact with something , but again no fuel pumps through when I try starting the car.

When looking through the hole in the engine block I noticed the cam is oval shaped, when a friend turned over the engine on the starter. So does the cam need to be in a specific position so that the activating arm can sit on top of the cam? Should I rotate the engine with a spanner and keep trying to fit the fuel pump, when the camshaft is in different positions?
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Re: Electric fuel pump conversion for 1256 engine.

Postby ADRIAN » Sat Dec 16, 2017 11:08 am

Its highly unlikely that there is anything wrong with the cam. Would love to see a photo of the fuel pump, and its operating arm to check that it is all correct. Can you post a couple?
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Re: Electric fuel pump conversion for 1256 engine.

Postby tynelord1969 » Sat Dec 16, 2017 11:22 am

ADRIAN wrote:Its highly unlikely that there is anything wrong with the cam. Would love to see a photo of the fuel pump, and its operating arm to check that it is all correct. Can you post a couple?

20171105_160542 (640x480).jpg
I've pasted a photo of the new fuel pump in above photo . It is the typical sealed unit which is the one on the right of the photo. The code on the arm is the same as an old one which was replaced 5 year's ago with the one on the left.
I hope the photo sends, but if not I'll re select it.
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