Talk Morgan Forums Morgan Sports Cars Morgan Aero 8, 2012< Plus 8, SuperSports, Coupe & Aeromax Hot start .... vapour lock

Appolgies if i seem to be carpet bombing the forum with posts - I'm (I hope) at the steepest part of the learning curve with my 'Mog at the moment, 3 weeks into ownership. Rapidly knocking things down as sorted, but still some niggles to get to grips with.

The car starts on the nail from cold and runs perfectly .... However. If its left to stand for 20 mins once warmed up it takes a very long crank to get it to fire up.

It always goes, but it can be 10 seconds or more cranking before it fires.

I'm pretty sure this is down to vapour lock - is it a known "thing" ?. Does anyone have a fix ?.

I've got a 2015 Aero Coupe, which I guess is going to be the same engine and fueling set up and it always starts immediately hot or cold.

I just googled it which made the following suggestions...

Crankshaft or Camshaft Position Sensors: As these sensors age, internal thermal expansion breaks down their circuitry when hot. They fail to send precise rotational signals to the ECU until cooled or subjected to extended cranking.

Fuel Pressure Leakdown / Leaking Injectors: If an injector drips or the fuel pressure regulator bleeds off pressure into a hot intake tract, a temporary rich or vapor-locked condition occurs, delaying immediate ignition firing.

Quick question as I am not that experienced on S5 and I know it was quite different due to the boot arrangement.

I have an S2 and a Coupe (yes I know, greedy). And the S2 has no issues. The Coupe can be fussy. The breather has been adjusted a few times and had several recalls. Is you starting issue perhaps related to the tank not breathing and so pulling back once switched off. So the restart is a bit starved? Not claiming any skills in this area but I did have that hot start issue after one of the “improvements”.

If it was a vapour lock I would be looking at the insulation around the pressure fuel feed from tank but nearest the engine.

Just before you try the hot restart next time, open the petrol filler cap (there's sometimes a rush of pressure in/out equalisation) and then try the hot start test

I have been messing around with the tank / breather to deal with fuel filling problems (see my other thread). Will definately try the "cap off" test next time it's warm.

I'm pretty confident about the one way breather valve (it's new a week ago) and changing it did not make any difference.

I have had issues with exhaust cam sensors (they put the EMS light on) but ive replaced both of them and the EMS light cleared itself after 5 drive cycles.

I'm planning to add an inline fuel pressure guage and if all else fails a "cooldown" fan, Regardless of the starting issues the engine bay gets incredibly heat soaked - I've even added some insulation on the bonnet stand rod as its too hot to touch comfortably. I suppose it recent UK temps have been a bit extreme, but it's done it again today @ 21C ambient.