check the faq about engine wiring harness problems. my son's 86 245 had a short in the 4 wire bundle that starts at the fire wall and goes to the starter, cold start sensor, somthing else, and then to the alternator. the sarter would engage, start the car then not disengage the starter. I also had an 84 240 that had the red hot wire to the computer short is the engine harness leaving the fuel pump dead. one jumper wire from battery to same wire at fire wall cured that problem. hope this helps

90 740 16 valve GLE, 89 740 GL, 86 245, 76 245