Leaky Fuel Pump - Daily Driver woes

alimorg

New Member
Hi All,
Just thought I would share this with you, the other day I started my 3500s and noticed a distinct smell of petrol, thought it was just that I had the choke out, so in went the choke and I drove home. The smell got steadily worse, so with the engine running when I got home I popped the bonnet. As soon as I did I could see the problem, fuel was squirting out of the pump from the joint that holds the diaphragm, luckily the squirt was in the direction of the radiator and not the hot exhaust manifold although I did now have an under bonnet area that was saturated with petrol fumes, so I quickly ran round to turn off the car and retired to a safe distance – back to work! I think I might invest in a fire extinguisher.

After waiting for the engine bay to cool sufficiently (A whole day seemed sufficient!) I returned to remove the fuel pump, looked fairly easy so I will run through it in stages:

1. First things first round the back to disconnect the battery

2. Ok back to the front and remove the fuel line into the pump – Mistake 1, the fuel line is metal and impossible to remove from the pump unless the pump itself has been unbolted from the block, so after what felt like ages of fuel pouring onto my drive I managed to re-attach the fuel line. Mistake 2 – Should have drained some fuel from the tank, it is mounted quite high in the boot on a P6 which gives enough pressure to allow petrol to flow freely from the supply pipe!

3. Remove the two bolts that hold the pump to the block

4. To remove the fuel line pull the fuel pump to the left and up (the pipe to the carbs is flexible so this is quite easy).

5. Mistake 3 – have your stopper for the fuel line close to hand and do not leave it on the kitchen table!

6. Run in and get your stopper from the kitchen – My stopper was fashioned from a 10mm dowel with a chamfer at one end and a child’s balloon (I used a pencil sharpener to chamfer the dowel but you could use a knife, whatever you use do not make a sharp point it will puncture the balloon)

7. Place the balloon over the fuel line and force the dowel into the pipe trapping the balloon, the dowel will deform to fit the hole and the balloon will create a fuel tight seal

8. You can now safely remove the fuel line to the carbs, and extract the fuel pump

9. Mistake 4 - Ensure the pump is completely empty of fuel and oil before you take it into the house to examine it - The wife was very happy about this one!

10. Tighten up the six screws that hold the pump together to cure the leak; at this point you may notice that the screws closest to the leak actually have stripped threads!

11. Go to your local DIY shop and purchase some 6mm machine screws with nuts

12. Re-tighten the fuel pump, this is where you may notice that to cure the leak in the past the non-stripped threads have been over-tightened to compensate for the stripped threads and give a wonderful arched effect between the screws.

13. Split the pump

14. Remove the diaphragm by compressing the spring and unhooking it from the lever

15. On a flat surface run the sealing edges in a circular motion on a piece of Wet and Dry until you can see a bright line all the way round. You should now have a flat surface.

16. Re-assemble the pump

17. Swear a lot when you cannot re-attach the diaphragm to the lever even with no return spring in place

18. Hold the fuel pump the right way up and easily re-attach the diaphragm

19. Kick yourself for not thinking of it earlier

20. Re-assemble the pump

21. Realise that it is dark outside and you will never be able to re-fit the pump tonight

22. Walk to work in the morning (in the rain)

23. Sit down and write about it

My final mistake of course was not taking any pictures! But I wanted to finish it ASAP, will let you know how the re-fit goes tomorrow.
Cheers
Al
 
You have my sympathy, my fuel pump packed up last summer after giving me some seriously strange symptoms.

I didn't have the gumption to replace the diaphragm though as the return valve could have also been the problem so I negotiated a price with Ray Weekly for a re-con unit on exchange.

Instead of blocking the inlet, a piece of washer jet pipe from a Mk1 Fiesta shoved down there created a nice gravity effect sufficent to stop the leak.

You wait until you try to put the pump back on, it's all down to getting the pump actuator arm back onto its cam, leave the pump slightly loose off the engine block to marry up the inlet pipe to its thread. Then all finger tight.

I would also prime it too by turning over the engine before putting the outlet on too, maybe a bit risky, again the washer pipe came in handy for putting this onto the outlet side pouring the outlet fuel into a coke bottle.

Fun, fun, fun.
 
Thanks Rovertron,
Unfortunately I read this post after re-fitting! ok so here we go with my re-fit.

1. Remove the stopper from the fuel line
2. Scratch head as to why only a small ammount fo fuel leaks out
3. Offer fuel pump up to block
4. Realise its not going to be an easy job as the cam is on its compression stroke so you will have to work against the pump to align the bolts
5. align the left hand bolt and do up finger tight.
6. Twist the pump so that you can align the second bolt
7. Realise that you cannot actually get your fingers in between the block and pump to do up the second nut.
8. Contort yourself into a position where it is possible to hold the nut between your index finger and thumb, whilst twisting the pump against its return spring with your palm and remaining fingers (even though I am left handed this had to be done ith my right hand which did not make things all that easy!)
9. Go round to your next door neighbour to borrow an extension bar for your socket set as yours has mysteriously dissapeared since last night
10. Whilst chatting to neighbour and his mate (both hard at it restoring MGB and Mk1 Golf GTi Cabrio respectively) realise it is now chucking it down and somehow your bonnet has closed (I can see my drive from his garage)
11. Stay chatting untill rain abaits, both suck through their teeth when I tell them what I am doing (Both own V8 Landrovers so have attempted this in the past)
12. Back to the fuel pump, Luckily it was my wife who closed the bonnet and not the wind. Unluckily she rushed it and did not clip the bonnet stay to the bonnet, which when I lifted the bonnet swung through a graceful arc and removed three wires from somewhere. I was sure they were important but could not for the life of me see where they had come from. Time for a top tip from my dad, hold up the wires jiggle them a bit and then drop them, after years of sitting in the same place most wires have a memory, when you let them go they return to their original positions. Hey presto two wires fall back to the washer bottle one falls to the coil, excellent!
13. Attach fuel line to pump.
14. thghten up pump bolts
15. Re-connect battery, turn the car over to prime the pump
16. Jump with fright as the bloody thing fires up first turn of the key (enough petrol in the carbs to get it going) turn it off quickly
17. Re-connect pump to carbs.
18. Re start the car (again first turn of the key is sufficient)
19. Wait for it to stop
20. When engine stops re-start it, and give it a good couple of blips of the throttle to make sure there is no more air in the fuel lines.
21. Run round to the front and check the pump for leaks If you are lucky there are none!
22. Wonder why the engine has cut out
23. Attempt to re-start car
24. Go back round to neighbour and borrow a starter pack as your battery is now flat
25. Re-start car
26. Wonder why car will not run for more than 10 seconds before misfiring loudly and cutting out (Wave at neighbour and mate who are now staning outside garage whith cups of tea diagnosing the problem)
27. Glance at fuel gauge, realise the tank is empty (see point 2 )
28. Pull reserve lever (thank god for reserves, why more cars dont have then I will never know)
29. Re-start car
30. Return Starter pack and Socket extension to neighbour, explain that your car is obvioulsy the best in the world as it has a reserve.
31. Have a nice cup of tea

There easy when you know how
 
Hello Alistair,
You've typed enough words on this thread to make an entertaining article for the P6 NEWS! - Why not cut and paste into WORD and send it to our editor?
Regards, John.
 
Hi John,
Do you not think its a bit, umm, oh I don't know umm light hearted for P6 News?
Cheers
AL
P.S. Would I have to cut the swearing?
 
Back
Top