Strange fuel issue.

[Paul99]

My 230SL had a problem today which I havent had in the past 12 years and 15,000 miles.

It is a hot day today (a rare thing in England!) and driving back after a 40 mile round trip I noticed that when trying to accelerate it was "missing" and hesitating.  When I backed off it was fine.

Got home and then 2 mins later tried to start it to put it away and it would NOT start.  Tested the spark - perfect so suspected fuel.
I removed the fuel line just before the fuel filter (which I changed a short while ago) and with the ignition on no fuel came out. So then I thought the pump wasn't pumping or a fuel blockage around the tank.
Checked the tank outlet and the fuel pump was pumping all ok.   

By this time the car had cooled down and started and ran fine.  This has never happened before even driving in very hot conditions.

So baffling.     Fuel evaporation of some kind?  Air in the system somehow?
Concerned it will happen again but as sods law says - only when I am a few miles from home

All suggestions welcome! 

[Lorsar]

How much fuel was in the tank when this happened?

[Benz Dr.]

I've seen where after everything cooled off the engine would start and run well. It usually ended up being a bad fuel pump.

Go to the back of your car after you turn the pump on and listen to how it sounds. If the pump changes in pitch or tone that's often a sign of a failing fuel pump.

[Paul99]

will try that.  The tank was 70% full so lots of fuel around.  May need to drain everything to search for a temporary blockage as the fuel pump is fairly new as well.