Diagnostic question:

89 740-T sedan. Was having issues with starting: would start up when cold, idle rough but be fine until turned off. Most of the time it would start right up again but if I let it sit and cool off for 40 minutes or so, it wouldn't start again until it had cooled off completely. NOW it won't start at all- cranks over but won't catch. If you spray starting fluid in the intake, it would kick over and "run" on that though. Also- car has been sitting for a while- noticed a light brown film on the underside of the oil cap. Dipstick seemed fine- nothing there and the car hasn't been going thru anti-freeze. What's up?

All help appreciated as usual.

-Jason

check the green wire at the injector for power with a digital meter, should be the same as the battery. no power-back up to the radio relay and try again. if the relay gets power but won't pass power, replace it with the cooling fan relay and try again. if the injector has power on the green side, go to the gray wire-should still have power until you crank it. then the ecu will pulse a ground on the gray wire to fire the injector. no pulse on the gray wire, back up all the connectors to the ecu and make sure there's not a problem in the harness, connectors, etc.

if the fuel system checks out, the look at the ignition system-cap, rotor, etc. a weak coil can fire ether but not gasoline. good luck, chuck.