Another hot start issue

I am having a persistent hot start issue for the last few weeks.

When cold the car fires up as normal and idles fine.

When hot, i.e. driven for 45 minutes to an hour at normal temp:

  1. If I shut down the engine and immediately try to restart - it fires up straight away.
  2. If I shit down the engine and wait to ten/15 minutes - it needs to be cranked a couple of times before it will start on the third attempt.
  3. If I shut down the engine and wait for an hour - it needs one crank and will always start on the second attempt.

It is very consistent. When I say it needs two cranks and will start on the third, it really will. It doesn’t seem to matter what the outside temp is or any other variable.

Another consistent symptom is that the fuel pump does not run for it’s normal 2 seconds when trying to start hot. Only after the cranking is done and the key turned again do you hear the telltale whine from the pump and then the car starts right up.

A lot of posts in the archives would suggest fuel pressure, but wouldn’t I expect the pump to be trying to prime every time if the pressure was dropping? And if there was a leak down or a check valve issue wouldn’t the cold start also be affected?

Any ideas where to start appreciated.

an old engine starting after three cranks doesn’t sound bad at all to me!

I would guess you’re just dealing with slight vapor/hot gas in the fuel rail.

Oh, just read your other part. Yeah, if the fuel pump is not running for it’s normal 2 seconds when hot, then you don’t have good fuel pressure to help start it. How old is your fuel pump? The fuel pump will prime no matter what the fuel pressure is.

I take it your fuel pump is in the tank? So not easy to replace…

FPR is another place to check, perhaps when it’s hot, it doesn’t keep pressure up high enough to start easily?