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Manual Pump Versus Electronic Pump


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Hi

 

Can anyone offer any advice regarding the following, sorry this is all a tad on the long side:-

 

Last year I bought a 66 TR4A, when I bought it the engine was running very rough

in that there was a strange hissing sound (which sounded like a leaking manifold gasket)

and when the ignition was turned off the engine always ran on.

When I questioned the previous owner his response was that the cylinder

head was a high compression head and the best way to stop the engine running on was to

drop the clutch - duh.

 

After some very lengthy research on this forum and speaking to an experienced engine builder,

the hissing sound was diagnosed as 'secondary ignition' ie too much fuel getting through.

 

The car is fitted with an electronic pump at the back of the car.

 

It was considered that the fuel pump was pumping at too high a pressure, apparently, the later

electronic pumps pump the fuel at a much higher pressure than the original pumps.

 

I therefore fitted a Petrol King Fuel filter/Pressure Regulator along with renewing various

parts within the SU Carbs. As a result the hissing noise was no more and the engine now never runs on.

 

My problem now is that at some point in the cars life someone has fitted a rubber fuel hose that runs the

length of the car from the electronic fuel pump to the engine bay. Needless to say I am not that happy

with this as I am not sure if the rubber is Ethanol proof (an issue I have had with a previous car).

I am very anxious to install the correct metal fuel line in place of the rubber pipe. Looking at all the supplier diagrams

there are no breaks or joins in these new metal pipes under the fuel tank region, so I am reluctant to refit the electronic fuel pump in the position it is as I will need to cut the metal pipe. (the noise this pump makes when the ignition is switched on is also irritating)

 

So . . . finally my question is would it be better to buy a repro original style manual pump that bolts to

the side of the engine or cut the metal pipe and stick with the electronic pump. On a side note I have always preferred original fuel pumps as the spares needed (a diaphram) are a lot less that a complete new electronic pump. Can anyone recommend a good manual pump supplier.

 

Thanks

 

 

 

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I found it easier to you the "nylon" flexible pipe from as used on Mk2 Jag from my pump at the rear to engine bay then steel tube from just above sump level up to the carbs. As for fuel pump there are those that annoy by making continuous noise and those that only click on demand similar to the old style SU electric pump. I prefer electric pump as it primes the carb bowls as you turn on ignition resulting in less cranking revolutions before engine start. I can also just here the pump during the prime (approx 10 clicks) but if it continued to click would indicate a leak or faulty needle valve ( been there before). Cannot hear pump when engine runs.

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I found it easier to you the "nylon" flexible pipe from as used on Mk2 Jag from my pump at the rear to engine bay then steel tube from just above sump level up to the carbs. As for fuel pump there are those that annoy by making continuous noise and those that only click on demand similar to the old style SU electric pump. I prefer electric pump as it primes the carb bowls as you turn on ignition resulting in less cranking revolutions before engine start. I can also just here the pump during the prime (approx 10 clicks) but if it continued to click would indicate a leak or faulty needle valve ( been there before). Cannot hear pump when engine runs.

Mk2 Jags originally only had a short run of nylon pipe at the rear from the pump to the boot floor and then from there to the front was a steel pipe then there was a short run of nylon up to the filter bowl and thence to the carbs (I raced a lot of them back in the Seventies)

Stuart.

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Hi Barry,

I have a manual pump. Vapourisation has not really been a problem. You can get carb heat shields if it is.

 

The only problem I have ever had was the pivot pin for the lever once migrated out of the body.

Thankfully the pin ended up stuck to some oil on the block.

 

I have since fashioned a pair of washers (underneath the attaching nuts/studs) with wings that stop the pin wandering about.

 

Roger

 

 

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Thanks for the info Roger.

 

After much deliberation I have decide to go with the manual pump.

 

I have just returned from Moss with all the parts including repair kit for the pump for the toolbox! ;-)

Old fashioned Belt 'n Braces you understand.

 

Thats this weekend taken care of then.

 

Barry

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Thanks for input.

 

All finally sorted, the rubber hose that I took off had a date stamp of April 1992 so I reckon its days were numbered and

doubt if it would have been Ethanol proof (a disaster waiting to happen).

 

Its nice to turn the ignition on and not have the pump banging sound, better reading on the ammeter as well ;-)

 

Take your point Pete, finger trouble I'm afraid, mind you I am well known to the Grandchildren as a balloon modeller so thats

probably where the 'manual pump' comes from.

 

Barry

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Call me pedantic if you like, but a manual pump would be awfully tiring on a long run! :D

 

We know you meant to type 'mechanical' though. :P

 

Pete

Love it :lol::lol::lol:

 

Cheers

 

Mike B)

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