'89 240 DL sedan 150K miles

Hi all,

So this is (I think) the third posting I am putting up regarding this problem in the last 6 months...

It still has problems with warm restarts. Specifically, if I let the engine warm up to normal temperature and then shut it off, leave it for anywhere between 5-30 minutes, and try to restart, I need a good ten cranks to get the engine started. Once it starts, it runs fine.

This problem does not occure if I attempt a restart just after shutting it off (< 5 minutes), or if I restart with the engine cold. Also, it appears heat related since it become more of an issue the warmer the outside teperature... i.e. I live in Montreal Canada and in the -25 degrees temperature a few weeks ago it was a non-issue completely...

The recent work I have done is:
New in-tak assembly (sending unit with pre-pump and hose) - it works great
New Fuel pressure regulator

Previous work I had done (in last 6 months)
New fuel pump relay
New crank position sensor
New 25A injection housing and fuse (waterproof)

Seeing as it feels like a fuel related problem... my next parts to replace are the check valve and fuel filter. My only concern is that these should have nothing to do with the level of heat buildup inside the engine compartment (the problem appears to be somewhere there).

Other then this, the car runs very strong and feels great. I do 600 miles/week with it.

Any ideas?

Thanks in advance,
Greg Mustang

'89 240 DL sedan 150K miles
'92 940 GLE sedan B234F 60K miles