Wallyiii

Any help in here? I have a well worn and previoulsy reliable 1998 ML-320; 200k miles, For maintenance reasons I had the fuel filter & line up grade and ran fine for a month; then died on road; after a few tries I got it going and drove home then died again; I replaced the Crank Sensor and after replacing the plugs ran good a few times now died again and no start. The new Bosch 4 plugs were some what fouled; I replaced those with Bosch 2; and now tries to start but will not; seems to be very weak spark; the ground to the coil I am checking with a led test light and it is weakly showing the ground as I try to start it; I put a inductive lead for my timing light on the plug wire near the plug and it will not flash; but then occassionally will start flashing (picking up the ignition from coil) and then tries to start or will start but will start and run with no power and then dies. I know this much:

Good Fuel Pressure
Has Spark at plugs out of cylinder and grounded (may be weak but sparks)
CAM Sensor seems to be picking up and groundinig on cranking
Crank Sensor puts out 5 volts AC on cranking at sensor
Injectors all spary on cranking and fuel seems atomized correctly
Good Pulse on injector harness
Free Exhaust

Could this be an initialization problem with computer though it did run good at times?
Can I perform this process with out the STARS tester? How?
Any advise would be appreciated.

paulocr

Hi
Did you find the trouble, I have the same problem with my ML320 1998, some times in the mornig it start 6 seconds and then die, I checked fuel pressure, injection, no codes present, CKP ok, CMP ok, grounds and feed to ECM fine. The only curios thing is a weak spark, very weak, I replace coils and the same result
thanks for any help