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mechanical fuel pump problems

PostPosted: Thu Jul 28, 2011 8:25 am
by miked
Has anybody had any problems with pipe leaks on the above? I have fitted/changed many over the years without any problems.
On the plus 2, that I have almost got ready to go back on the road, I changed out the glass bowl pump as the lever pin was sloppy etc. Fitted the small metal top one.
I had a terrible leak on the input plastic pipe. Removal revealed the inner olive seating area (in the pump) to have breached and allowed the olive to roll over. Re over tightening, this was progressively tightened from just a nip to hold the leak.
Fitted a second new pump. This time I used a short metal pipe in the input and then used a short rubber pipe to join the plastic to the metal. Lowered the nose of the car and all was dry. Left it for a week or so and started the car last night. Low and behold the output is leaking very badly. The output is the proper Weber braided job with the short metal pipe bit going into the pump. I won?t know what the score is until I pull it all out again to examine the seat and olive. I have another new pump and looking in the fitting holes they don?t seem to have good seats. The old glass bowl one has proper seats.
Getting fed up and thinking Electric. Should not have to! Not a good area to work on. Very tight.
Has anybody else suffered? Could it be a batch problem? Perhaps all these come from the same origin/source?


Mike

Re: mechanical fuel pump problems

PostPosted: Thu Jul 28, 2011 11:14 am
by archigator
I like keeping my Sprint as stock as possible, except for concealed items like starters, flywheel, etc. When my stock AC fuel pump ceased to function,I had my fuel pump rebuilt by Then and Now Automotive in Weymouth,MA.
http://www.maritimedragracing.com/antique_auto_parts_cellar.htm

They disassembled it, bead blasted it, rebuilt it with new parts, tested it and returned it back to me in under one week... all for $85 bucks. They did a super job, and I highly recommend them. I fitted all hose fittings, on both sides of the pump, with teflon tape on the threads and the output pipe. In addition, I replaced the compression fitting on the stock plastic fuel line. (You can buy compression fittings at your local hardware store.) I've had no leaks.

Gary
'71 Sprint FHC
Miami, Florida

Re: mechanical fuel pump problems

PostPosted: Thu Jul 28, 2011 9:09 pm
by Robbie693
Before I changed back to an original style pump I had leak problems with the all metal type. For the outlet pipe leak I found the olive had 'necked' the metal pipe part of the braided hose so I cut a bit off and fitted a new olive. I also used Wellseal on the backnuts and managed to cure the leak. At least from the pipes. The body leaked as well, which is why I replaced it in the end.

Robbie

Re: mechanical fuel pump problems

PostPosted: Fri Jul 29, 2011 12:18 pm
by miked
Thanks Guys,

I have not had chance to get back in see the exact cause of the leak in the pump output. I started it again and looked with the torch and it is a tidy leak. Having considered it all and slept on it I feel an electric facet coming on. I did it on the last S4 with Filter King, pressure check and inertia switch etc. I am not generally short of patients but working in that area with relatively large hands is annoying the living sh*t out of me. I dont disagree they can be very reliable and last for a long time.

One last look and its if it is something I have done I will remedy. However, if it is poor aftermarket parts, it is "fired" and I will do electric for the reasons of accessibility. I can also carry a second spare pump on a long trip. Classic Leman 2012.

PS I class this area/task on a Plus 2, the worst one. You name it and I have done it Elans & Plus 2s but this takes the biscuit. The heater hose makes it worse. Easier on a little Elan. More so with Strombergs.

Mike

Re: mechanical fuel pump problems

PostPosted: Fri Jul 29, 2011 5:32 pm
by GrUmPyBoDgEr
miked wrote:Thanks Guys,

I have not had chance to get back in see the exact cause of the leak in the pump output. I started it again and looked with the torch and it is a tidy leak. Having considered it all and slept on it I feel an electric facet coming on. I did it on the last S4 with Filter King, pressure check and inertia switch etc. I am not generally short of patients but working in that area with relatively large hands is annoying the living sh*t out of me. I dont disagree they can be very reliable and last for a long time.

One last look and its if it is something I have done I will remedy. However, if it is poor aftermarket parts, it is "fired" and I will do electric for the reasons of accessibility. I can also carry a second spare pump on a long trip. Classic Leman 2012.

PS I class this area/task on a Plus 2, the worst one. You name it and I have done it Elans & Plus 2s but this takes the biscuit. The heater hose makes it worse. Easier on a little Elan. More so with Strombergs.

Mike



Well!
If that's the case Mike come on down to me & fix my car's door lock actuating rods please. :wink: :wink: :lol:

John

Re: mechanical fuel pump problems

PostPosted: Fri Jul 29, 2011 6:45 pm
by Galwaylotus
miked wrote: I am not generally short of patients but working in that area with relatively large hands is annoying the living sh*t out of me. Mike

So you're a doctor then! Do you have patience with your patients? :lol: :lol: :lol:

Re: mechanical fuel pump problems

PostPosted: Fri Jul 29, 2011 7:48 pm
by Elanintheforest
Mike, the small metal top pump is, I believe, from the 71 onwards Capri, and a somewhat higher pump rate. If you replace with original equipment (reconditioned) you won't have a problem, unless you have now knackered the olive on the petrol pipe.

Reconditioning kits for the original pump are available for a few pounds.

Mark

Re: mechanical fuel pump problems

PostPosted: Fri Jul 29, 2011 9:45 pm
by miked
Thanks for replies

John, Yes pain in the bum inside the door but you can sit/kneel and play at Doctors working through a letter box. Happy to have a go. :lol:

Galwaylotus. You caught me out! Not my strong point English. :D

Mark re old pump. I was considering a service kit but the lever pin is very worn so I would have to sort that out on the lathe etc. I read on here that you don't get all the parts in the service kit. That also put me off.

I dont think the olives should be damage as both inlet and outlet have metal pipes. My money is on the pump seat. Will find out in the morning when I take it out.


Mike :)

Re: mechanical fuel pump problems

PostPosted: Fri Jul 29, 2011 10:39 pm
by seaandmoor
I'm grappling with same problem of knckered pump.
Let me know if you go electric as it's my line of thought aswell. Be interested to hear and see (photos please) what you use for pump, regulator, power supply, location of new parts, particularly new fuel lines etc. And before anyone says it yet again, I am TOTALLY deaf to all the people who spout pap about mechanical pumps are safer in an accident.. I don't care, see, so there, ya boo sucks. I'm going to go up in flames one day anyway :twisted:

Re: mechanical fuel pump problems

PostPosted: Sat Jul 30, 2011 11:17 am
by Galwaylotus
My S3 came with an electric pump. It's p***ing rain at the moment so photos will have to wait but here's the description:
Fuel tank outlet through short hose to plastic filter.
Filter through short hose to pump inlet.
Pump outlet through short hose to metal fuel line running to engine compartment.
Metal fuel connected to carb inlet through another short hose.

Fuel pump is a small round electrical unit held in place with a custom(homemade by the look of it) bracket and large hose clamp. I'll try to get details when the rain stops!

Re: mechanical fuel pump problems

PostPosted: Sat Jul 30, 2011 2:23 pm
by Galwaylotus
In between showers.
By the way, I forgot to include the pressure regulator in my earlier description. It's after the pump and before the metal fuel line to the engine bay.

Re: mechanical fuel pump problems

PostPosted: Sat Jul 30, 2011 3:13 pm
by seaandmoor
Hi Galway,
Well that doesn't look bad or too difficult - might be able to put it under the boot floor in Plus 2.
Any idea what make pressure rugulator - don't need it too high for dellortos. Also regarding the pump, when the ignition is turned on, does it pump until the carbs are fed and then stop until the engine is started or is it pumping constantly?
Thanks very much and hope the sun shines soon for you.

Re: mechanical fuel pump problems

PostPosted: Sat Jul 30, 2011 3:32 pm
by Galwaylotus
I'll have to try and see if there are markings on the regulator. Might be a while before I can check it. The pump operates until it reaches a set pressure (don't know what that is) and then stops until the pressure downstream drops, i.e. when the engine is using fuel. I can't see any brand marking on the pump either but I'm sure any of the normal Facet type low pressure pumps will work.