starts only sometimes-lambda light does not burn

Hello, I have the following problem: car doesn’t always start. Sometimes when the 4th starter spins, but usually helps only wait and try again. Waiting is about 5-20 minutes. No connection to warm or cold engine found. But: when the ignition key does not turn the Lambda light, it does not work; lights it up, the car starts. If it runs, there are no problems, the engine runs like all the years before. Car: Volvo 850 with B5204T2 engine (Italyimport, 170 hp, 265,000km, car gas since km 160.000) So far tried: fuel comes with sufficient pressure from the valve at the end of the injection rail ignition (twilight lock) bridged with cable from battery to ignition plus on the ignition coil no spark, if one holds a cable to the ground from the output of the ignition coil to the ignition distributor (if he just doesn’t want to). Thanks some successful repairs to this forum (ABS sold back…), here at my first topic thus thanks to all who help one here.