1991 745 Turbo 113,000 miles- wife's car

This car has never been quick to startup, but it has never failed to do so until today. In the past several weeks it seems to have required more cranking time before finally starting. The fuel pump relay was replaced with a newly resoldered one several months ago. The cap and rotor have 15,000 miles on them, the fuel filter was replaced 14,000 miles ago and the throttle body was cleaned last week when I was informed of increased cranking times and occasional stalling immediately after starting.

I got a call today from my wife that the car refused to start at the local grocery store. I arrived on the scene with a replacement car and no tools. It would crank over nicely but would not fire. I tried four different times with increasingly longer starter engagement times to no avail. The pumps would cycle when the key was moved to the on position so I'm not quick to point a finger at the fuelpump relay. I looked for a ticking movement from the tachometer that was always present in my 1990 740 GL and didn't notice any movement while cranking the engine over (I don't know if the tach in the turbos "ticks" like that or not) I have a road service contract that I have never needed to take advantage of before so I called for a tow.

Once the car was home and I had had lunch I went out to check it out and was disappointed when it immediately started. It has started immediately on every retry since.

First question has to be do the tachs in the 740 turbos "tick" on cranking? The car starts so quickly now that I wouldn't be able to notice any ticking if it did exist! My first guess would be a flywheel sensor if ticking is normally present on these cars because it sure wasn't moving when it wouldn't start.

Anybody got any direction to point me in on this one? Similiar experiences and your own solutions? I won't hold anyone responsible for not supplying the correct answer nor will I whine if you give me bad advice that in the end costs me money...... Thanks

Randy