I've got an '89 745 Turbo. Runs really well, but as the weather has gotten colder in the past couple of weeks (Vancouver, so now down to about 7 deg C/45 deg F over night) the car has suddenly become reluctant to start in the morning. Once the car has been driven it will restart every time with no trouble for the rest of the day, even after sitting all day at work.

I don't think it's ignition-related, because once it's been started, or if the ambient temperature is above say 15 C/60 F it starts right up (even if it's raining) and once started it runs with no stumbles or hesitations.

After a fair bit of cranking it does start, but this morning it was even money if it would start before the battery gave up. Apparently also time for a new battery...

Anyway, can't think what it could be. Fuel injection sensors all appear to be OK, as do vacuum lines. FAQ suggests the check valve in the fuel line as possibility. Possibly sitting 14 hours over night at home vs sitting 8 hours at the office is enough time to lose enough line pressure? I've replaced the forward (pressure) fuel pump about a year ago - maybe the rear pump should be replaced as well?

Any suggestions?

thanks,

Bruce