I have a 5.6 in 87 560 sel and after purchaseing a MD factory repair manual on disk, after having mitchell on demand and after getting a hard copy of the MB 5.6 engine repair manual, where are the correct timing marks on the drivers side cam towers? one other question for now, does the fuel system control unit (AKA ECM) ground the temp signal for the cold start valve on pin # 7. Right temp going in wrong going to fuel pump relay. thanks for any help in advance. Note do not attempt these things on your own.