Petrol on floor

[RichT]

Hi all

Time for a question

For some reason only known to my self I switched the ignition on for about a minute before I started the car mk 2 3.4 with standard carb set up

Fuel pump ticked away, when I started it and backed out of the garage nice pool of petrol where the car had been, no leaks where the car had been idling which is probably why I am still alive

On inspection no obvious leaks to be found I suspect that the fuel had escaped from an overflowing carb and out of the nipples at the base of the manifold

Before I check for flooded floats (which I will do)

Could it be th auto enrichment device causing the flooding as other su equiped cars I have run if you leave the fuel pump running the floats shut off the flow of fuel and the pump slows

Any thoughts appreciated before I attack it this weekend

Many thanks

Richard

[piman]

Hello Richard,

probably your first suspicion as the auto enrichment device is fed from one of the carburettors so is float controlled.

Alec

[Martec]

We have not long got back from a tour of Scotland in the MkII, and although most things went well I noticed each morning during the daily inspection that the level in the filter bowl had dropped which I put down to evaporation and nodoubt the same in the carb float chambers. So the float valves will be open and the levers hung down, where they can jam, then not close the fuel valve and so overflow out of the drain pipes off the inlet manifold.

This was covered by a prevoius talk at a Castle Bromwich seminar, the answer is to remove the top of the float chamber and remove the hinge pin so as to bend the BACK of the lever to stop the lever dropping to much and so jam. Care must be taken to ensure you have not bent the front of the lever which controls the fuel level in the float chamber (sounds more complicated than it is).

I did this, but on one occasion this holiday it did flood (parked stern down!!), but my special tool fixed it, a nicely weighted screw driver used to tap the top of the float chamber, job done.

Best of luck
Brian

[oldtimer]

Petrol on the floor seems to be the flavour of the week. Yesterday I fired up my XJ V12 (on Stromberg Carbs) for the first time in many months. With some antics with the manual choke control and throttle managed to frighten it into life. There was a fair amount of popping and banging but got it to run smooth at 1800rpm, this was followed with a loud bang and the engine stopped, Oh sod it or words to that effect and gave up.

The big surprise came when I got out of the car and noticed what seemed like 1/2 a gallon of petrol on the garage floor. After clearing up I gave up for the night but I suspect it will be a float chamber job.

Hopefully a sharp tap on the float chamber will put things right otherwise it's a partial strip down job.

Oldtimer

[RichT]

Hi guys many thanks for replies I will whip float chambers off and check I think you are right just stuckthe flow of fuel stopped when the engine was running I guess they unstuck, which incidentally is probably why I am still here I guess this is just the punishment I get for not using the car enough even though I treat it to super unleaded

I have always been puzzled why the nipples on the manifold are not connected to some kind of return to the tank except then I guess overflowing wouldn't be so obvious

[oldtimer]

Hi Rich,
Going back a very very long time I seem to recall that black plastic tube was connected to those two nipples and held in place at the bottom end by a clip attached under the head of a bolt securing the filter housing. But of course I could be dreaming it !

The float chambers also have copper drains off the top.

In the many years of running Jaguars as a daily car, MK5, Mk 7 Mk 2, old S Type etc. non of these suffered from flooding problems. I do believe the currant problems are a lack of use and in some cases lack of maintenance.

A sharp tap normally cures the flooding float chamber.

Martec refers to bending the anti - tip strut on the float valve control arm. I'm blowed if I can remember ever coming across that arrangement - perhaps it was introduced after my time of involvement. It might be worth exploring a retro fit at some point. It might be worth having a word with Burlim fuel systems, Spitfire House

Oldtimer

PS Time to get back to my car