E28 NO START: Troubleshooting guide.
Before you check anything fuel related:::::: Check for spark, super Easy, and quick,,, Plugs, Wires, Cap and Rotor, and Coil, All easily accessible and Cold Start Valve!
1- Check Main Relay, and Fuel Pump relay: Best idea to simply change both. they are really cheap!
2- There is one more relay many people overlook and that is the OBC Relay: If your E28 is equipped with the full On Board Computer, and Has the "CODE" function, that Code Button allows you to enter a Fuel Kill code, to disable the fuel injection system for theft protection! so if your OBC Relay which is a Large black box under the driver steering Colum, then that will cut power to the fuel injectors and NO START.
3- Once you have ruled out steps 1-3 Move to checking the fuel pressure regulator- When you crank the engine, check the pressure in the hose before and after the Fuel Pressure Regulator.
3- If that passes, next thing to check would be the fuel filter and BOTH fuel pumps, Pre- In tank, Elec near the Fuel Filter, When was the last time you changed it??
4- If all else Passes you have a BAD MOTRONIC ECU which controls your injection system..........Located in your Glove Box under the vinyl cover/flap!
Listen......If you ain't first, You're last! "Ricky Bobby"
Last edited by LSB M535; 05-27-2010 at 02:22 PM.