930 start problem
 

Have a 1987 930 and having trouble with starting. Engine rebuilt last year and was running fine. Seems when it hit hot and sitting in parking lot, won’t start. One it cools, will start. Has gotten progressively worse. Now it won’t start at all. Fuel pump does not run when first turning on ignition. Very frustrating. Likely electrical I am thinking. Checked fuse in front trunk and good. Think it may be faulty fuel pump? Fuel vapor lock? Other fuses I could check? Appreciate any input.

You usually have two fuel pump relays and two pumps, you should hear them cycle when you turn ignition on. pull the relays, clean them and be sure they are tight. Search the forum for " car won't start" there are many threads dedicated to this subject.
Good luck and welcome to the forum.!

Typically both pumps will cycle on for just a fraction of a second when you first turn on the key, or not at all depending on the condition and/or make of the infamous yellow relay. If the plug to the air flow sensor metering arm has been disconnected, then they'll run continuously once you turn on the key. In other words, don't expect to hear them run until the engine is running as per the stock OEM design. I doubt fuel pumps are your problem, but you could always unplug the connection to the metering arm to confirm that your pumps will run when you turn on the key.
I would suspect ignition problems, heat soaked CDI or coil since this seems only problematic when sitting hot...otherwise starts and runs fine.

Seems like I remember hard starting problems in CIS 911's that turned out being the fuel accumulator. Keeps pressure on the system to prevent vapor lock? Inexpensive and available part that could be worth a look.