This incosistant starting on volvo 740 GLE fuel injection is quite common. The issues are usually:
1. Fuel pump servo (in dashboard behind ashtray).
2. Fuel pump itself (under car passenger side UK) Gets dirty
3. Sensor in the distributer
4. Sensor on the engine - hot start sensor
5. Ignition Coil
6. Distributor cap and rotor arm
My checking FINALLY got the answer -after weeks. I changed the Hot Start sensor and the fuel pump relay and the fuel pump and then the distributor. And the coil and the sizzy cap and rotor arm. It then started first time and I thought HOORAY. Then next day it stopped again!!!!!!!!!!
The answer: Having the bonnet (hood) up and engine running - with rubber gloves on, I fiddled with the distributor cap and leads and wires and 'heard' electrical 'noises' from the distributor cap area. The low tension feed to the distributor is a thin, braided and insulated cable going to a solid pinned socket. The cable had suffered from heat and had become brittle and crisp. The cable was so brittle it would dissolve in between your fingers if you rubbed it hard. I cut the cable and renewed it with a piece from a scrapped volvo. Job doneHope someone can learn from my hard earned lesson!!
Thanks for all the help guys
Regards
Billy UK