I changed the fuel pump & fuel filter & my car still won't start.
what else can I do to get my car started? on 1993 Mercedes-Benz 300SE
1 answer 1 comment
You need to follow proper trouble shooting procedures to see that you have fuel and spark and engine mechanical integrity. Replacing parts without proving they have failed will not be cost effective. The SE has electronic fuel injection. Check for fuel pressure (you will need a fuel pressure gauge and look up the specified fuel pressure for your vehicle). Remove the fuel hose that goes to the fuel rail and get a friend to crank over the engine to see you have adequate fuel volume (you should have approximately 1 pint of gasoline in ten seconds of cranking). Off course take proper precautions as gasoline is highly flamable. Next "listen" to the fuel injector. Using a mechanic's stethoscope (or use a long screw driver placing the handle end up to your ear place the metal tip end of the screwdriver against the body of the fuel injector), get a friend to crank over the engine while you "listen" to the fuel injector listen to each injector at the same point of the injector body. You should hear "click, click, click" as the injector is electrically opened and closed by the computer. If the injector is not being triggered you will not have fuel getting into the engine's cylinders. Disconnect the electrical connector at the fuel injector with the ignition key in the "on" position, (next position after the accessory position) you should have 12 volts at one of the two wires at the injector. This true for most vehicles but you need to consult a workshop manual for your vehicle to see that this is true for your vehicle. When the engine is running the second wire at the injector gets (triggered) grounded by the computer in your vehicle many times a second controlling exactly when and how much fuel gets injected into the engine. Check for spark at the spark plug as a friend cranks over the engine. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online
Thank you for this helpful info. I had to replace the Engine Computer Module Now the car starts now I have a promblem with it misfiring it runs very rough now. There were new spark plugs installed but the wires wasnt changed. You think that could be the promblem?