Ls400 petrol evaporation on starting in hot weather

[Malc]

Are any of you finding this an issue at these extreme hot temperatures we are experiencing right now ?

For two days running, upon start-up there seems to be a little hesitation and it seems to me that maybe, momentarily ( a moment's short sharp unhappy misfiring like noise ) that stops the old lady from wanting to start easily. It does start of course, immediately after the hesitation, and it's definitely not the starter motor ( I think )  it just seems a little petrol starvation maybe and I'm just wondering if it's super evaporated in the engine management system before it gets to be ignited.

Just a hot weather related unusual matter ?

Any thoughts please

Thanks

Malc

[Cotswold Pete]

I would think it is not to do with fuel evaporation, unless you have an issue with a leak or some other issue in the fuel line where the heat causes the crack (or whatever it is) to expand and you have a pressure feed issue.

Just one other thought (based on experience with Mk2 and the failing/stalling ECU problem) is the ECU electronics maybe misbehaving a bit due to heat.  I always had more issues with the ECU when it was hotter.

Not sure (and others may have some different thoughts) as to whether fuel pump may be starting to give you gip.

My Mk4 fires up no problem and the last few days it has registered 27/28C sat outside of work.

 

[Malc]

.  it was 33C  here  

Malc

[Cotswold Pete]

Siesta time But don't tell the boss

[skyway]

Hi I just came back from a trip to france (no aircon 37 deg 45 in the car or bloody sauna as we now like to shout at it ) and while I was there my car did have some hesitation on starting after it had been driven, although It was fine at 1st start up in the morning.

I have changed the coolant temp sensor, so I think now all that is left is for me to hit is with a hammer.