it is my first thead on this forum , I am more used on X350 one , so I would like to says hello to all old jag menbers

I just have a strange ( and unknown for me ) issue with my Daimler Sovereign ( 420 )

it starts well from cold even after one or two months ( with battery saver of course ) , but when hot ( after a drive or even after 20 mn at idle ) if I cut the engine , it restarts ok if I do the restart less than 5 sec after the engine is of , if I wait 10 sec or more , it is impossible to restart ( need to wait at least 15 mn to start with a little throttle open )

there is ignition
I even try to connect the electric choke when the engine is hot , but it don't works

I tried with both fuel pump , it change nothing

I was wondering if it can be a fuel issue because fuel is inside the tank for more than one year ( SP 98 )

If anybody already have this kind of problem I am interested to know what was the cause

I will first try to replace the old fuel with fresh one and see what happen

Best regards

Philippe

 

Hi Philippe,
This is not a new problem, my S-type was like this from new (dad bought it in 1966). It is fuel evaporation in the hot engine bay. Better people then my will give you solutions but you might look at insulating the fuel lines and/or fitting heat shields to the carburettors.

I just except its one of those things and it's not a great problem as the car doesn't get used much, if at all ..........

 

Hello Peter , thanks for your answer , I was thinking like you when it happened last summer under 30°, but last test was performed last week-end and temp was around 5 °C and I let the bonnet open during the test , carburetors were not hot at all , but it failed the same way ( it is even getting worst )
in the ast years I run in quite hot conditions without any issue , it seems something changes or became weak ( an air leak maybe )

had no time today to replace the fuel , but vill do it as soon as possible ( old fuel will be ok in my Land rover which can run with very poor quality one ! )

 

Ok, if happening in cold your air leak theory could be the way to go.

Peter

 

Air gets into the inlet manifold via the carburettors, (of course !), but other avenues can open up like the vac line supporting the vacuum servo. If this gets a leak somewhere, the result is not "suction" at the twin SUs so fuel is not drawn into the engine. Leaks are common when the reservac tank rusts out.

Q1. Does it tick-over OK when warm ?
Q2. Are the brakes OK ? (If the reservac tank is leaking, there will be no servo assistance)

 

Finally , ( I didn't run the car for a few month ) the solution was found during last MOT test ,

after a 45 km trouble free run to go to the MOT center , it was impossible to restart the car after only one min stop

with the help of the technician , we saw that ignition was quite weak on cranking
it seems the engine was ready to start ( we heard one firing ) when I stop the starter motor ( maybe because there is more power for ignition during the very short time between the starter stop and the ignition stop )

starting was ok when during engine rotation with starter , we unplug and plug again the ignition coil a few time

As all ignition parts were quite new , and I already try with new coil without succes , so I fit new condenser and it is ok !

the old one had made less than 5 years and 3000 km ,it seems some aftermarket parts are not very realiable

Hoping it will help other menbers , for me it is the first time I see a condenser working ok from cold ,but not when hot

 

Time for an electronic ignition.
Concerning the condenser _ there are numerous after market parts and even factory parts made in China and unfortunately the quality is dreadful.
Chine can make descent parts if a given company tells them to do so, but they want to have it made as cheaply as possible and this is what happens.