I used to have a European 740 Turbo 89 model, that was occasionally sensitive to poor signal across the flywheel motion sensor connectors (two of them). I think the engine used to turn over on the starter but wouldn't fire (and had no spark). Reason's probably that the fuel injection is shut off for safety if the lack of signal from the flywheel sensors suggests that the engine isn't seen as turning over. Fix was to locate the two thick black cables going towards the top of the back of the engine around the distributor area, disconnect the connectors to the leads going down to the top of the flywheel housing (one cable at a time, they look identical and apparently don't work if crossed over), spray with switch cleaner and re-connect. I've heard that if connector blades and contact fingers are corroded, it may be enough to break and remake the connection, the force of reconnecting wipes off the corrosion. Apart from corrosion, oil blowback from the engine oil filler cap or dirt/damp blowback from the road, can cause these leads and connectors to get dirty. Checking them would be worth a try, doesn't cost much unless a connector comes to bits in your hand ! If not, there are other sensor leads that can give trouble. Does your engine turn over at all? I think the air mass sensor device, the intercooler air temperature sensor, and the air intake temperature sensor, were all places where I tweaked connectors occasionally to get it to start, though generally the car was very reliable and fired at the first turn of the key 99% or so of the time.
"NVRosie" wrote in message news: snipped-for-privacy@posting.google.com...
Does the engine turn over?
The engine does not turn over!
740 Turbo 1987. Turn ignition key and all lights/fans come on, hear a click in the relay/fuse area and a click outside (suppose fuel pump?), but can't start the engine. Jump starting is no help either. Tested all fuses and the battery - all OK. Checked (removed and wirebrushed) the cables to the starter. Where else could I try and troubleshoot? Anything else an ordinary guy can do? Thanks!!!Are you getting voltage to the starter? Does the voltage remain when the key is turned to the start position? Also check the small wire going to the starter, if that gets voltage when the key is turned to start then the problem is most likely the starter itself.
Did you check the ground wire? (Negative battery to engine.) Check the small wire at the starter. When trying to start, this wire should have
12V on it (use a test light). If not, then check the neutral switch (assuming automatic), and the ignition switch. If there is 12V at that wire, then the starter is bad.MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.