Fuel starvation ?

[VixenPPP]

Test drove PPP ' Vixen ' again yesterday evening . All good for 3 miles or so then she spluttered and juddered and ran erratically until she conked out. By disconnecting the fuel hose and cranking the engine confirmed fuel to the carbs, but, I've done this many times and this time the pressure seemed excessive. It conked out three times before limping home. Essentially, after checks, it seemed a matter of time before she would restart. I'm thinking examine the carbs, replace hoses, second fuel filter maybe. Are electric pumps recommended ? MK 2 Vitesse.

.....Neil

[Pete Lewis]

if it restarts after a stall there are two ideas here

1, do check th coil is polarity correct   neg to dizzy   pos to white ignition feed 

2,  rubber slivers in the fuel line  jams the back of the float needle valve  leave it the pressure drops they flaot back down the pipe ready to repeat agin very soon 

extra filters or change of pump wont cure these .   and you say  the pump seems to be providing fuel ok.

rubber slivers are a common headache  when refitting a fuel hose  the metal [ipe shaves a small sliver off the inside of the hose 

especially cheap nasty repro fleabay hoses 

Pete

 

[Nick Jones]

Given you’ve confirmed fuel to the carbs and there are two them…. Why are we not thinking this could be an ignition problem?

Coil, condensor, rotor arm? I have had the latter give very similar symptoms.

Nick

[johny]

yes typical of fuel restriction is misfiring as the load (and fuel consumption) of the engine goes up but then runs ok again on tickover. Alternatively something can be floating around in the tank and block the outlet so the engine cuts out which then allows the item to drop off and the engine to run ok until the next time...

[chrishawley]

I'd explore foreign bodies on the back on the needle valves as the first thing because it is very easy to get a definite diagnosis or at least be able to firmly exclude that diagnosis. Admittedly having to take the carbs off is a tad tedious and more so if one (!) has forgotten to have spare float chamber gaskets to hand if required.

That said, and having removed the needle valves, if one blows backward through the valves with an air duster or WD40 onto a piece of clean tissue paper clear evidence will be produced of whether or not they were obstructed (although rubber bits are usually pretty obvious just on inspection).

A related matter to is to ensure that the metal interconnecting fuel pipe between the carbs is not, itself, full of detritus which will then continually feed forward on to the back of the needle valves. Mine was full of debris and needed a thorough clean.

And when replacing use only new, top quality, ethanol proof, rubberhose from a reputable source.

[VixenPPP]

Further to my conking out problem. I've looked at possible faults you gents advised. I've had the carbs off, thoroughly cleaned them, needle jets were clean and I've recentered the main jets. Fuel lines are fine. It appears to be an ignition fault. Anyway I've fitted a powerspark ignition kit. She fired up instantly, but, sounded very rough and blew the emission control disc thingy off the manifold. On trying to start her, the engine turns freely then slows to a point where it almost stops then runs freely again. She fires up, but will not run. Ignition timing or something more serious ?

....Neil

[Pete Lewis]

fitting electronic to the dizzy must be re timmed as the rotor is not in same place as the points cam 

so do a static or strobe test to retime 

Pete