Hot Engine Starting ? :(

Hi
Im having trouble with starting my 86" when the engine is warm (say a 30-40 mile run) which I know is quite far for an old girl! I had a defective coil which was changed and seemed to do the trick for a maybe 3-4 trips but now once again she just refuses to start when warm! Give her an hour or so and she's fine again.

Any ideas?

Cold starts are no problem and warmish engine is still on the button. I'm a bit baffled to be honest - Im gussing theres a fuel problem but I cant think where?

Please help!

This is a common symptom of fuel flooding.

Basically, the fuel level in the float chamber is too high AND/OR the needle valve in the float chamber is not stopping the fuel flow as it should when the float rises, or the float itself is holed and sinking.

While the engine is running it manages to struggle along but is probably using a whole heap too much petrol.

Then you switch her off.

The excess fuel (including a heap still pressurised in the lift pump) then overflows through the carbytooter jets and pours into the inlet manifold and then runs to the cylinders. The fuel / air mix goes down the pan - too much fuel and too little air - and so it wets the plugs and she won't fire up. Indeed, if the fuel air ratio gets too rich even if the plugs do spark it still might not fire up.

Solution?

If this is the cause, take the lid off the carburettor - sorry Slob, Carbytooter - and do two things:

1. set the float lever properly

2. check the float needle valve seats properly. You can blow into the inlet, and when you lift the needle valve it should not let air through.

Be aware that this problem always results in quite a bit of petrol passing the pistons while the engine is sitting flooded. This carries all the oil off the rings pistons and cylinder bores (BAD PLAN) and fills the sump with petrol and petrol vapour (VERY BAD PLAN).

I think you should sort this PDQ.

Meantime when hot try this:
DECK the gas pedal and hold it down - DO NOT PUMP IT.
Apply starter motor till it runs or battens flattery.

CharlesY

CharlesY said:

DECK the gas pedal and hold it down - DO NOT PUMP IT.
Apply starter motor till it runs or battens flattery or the vapour in the sump blows you sky high......

CharlesY

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Soz, will get me coat...................................

Codbasher said:

Soz, will get me coat...................................

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I never tried to frighten the poor guy about blowing his injun sky-high, and I have never seen one do it, but I have heard stories ..... sump-pans and rocker-covers blasting off .... and the like.

But let's hope the diagnosis is right because it's so easy and quick to fix float levels and float needles. It might just be a bit of dirt holding the needle off its seat. Filter .......... filter ................. filter ........... can't have enough of them.

CharlesY

All sorted!

Rusty residues under the float cleaned out, needle was a bit grimy too. Amazing what a difference a bit of dirt can do.

Thanks guys

jondee10 said:

All sorted!

Rusty residues under the float cleaned out, needle was a bit grimy too. Amazing what a difference a bit of dirt can do.

Thanks guys

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FIT and INLINE FILTER!! One of those cheap easy clear plastic ones!

Buy several and carry a spare.

Good fix though!

CharlesY