frknu
10-13-2011, 05:03 AM
After complete rebuilding of the engine due to seizure on 2 cylinders, engine running lean. Took the boat out for a test drive/break in connected with a smartcraft diagnostic system.
- Engine runs clean and much smoother then before on idle and low rpms.
- Only strange thing we noticed while running steadily @ about 4000 rpms, we could see some strange rpm fluctuations on the diagnosic laptop. RPMs was wariyng from about 3900-4200, looking at the diagnostic. however listning to the engine it was running at a steady RPM, no rpm changes could be heard. So obviously there is something interferring the RPM signal?
- at one stage rewing the engine while trying to get on plane we could see the RPM readings on the diagnostic showing all the way from 1000- 9000 RPM!?, and the engine completely stalling out. This 9000rpm reading offcourse cant be a real one.
-assuming its the trigger (crank position sensor) which records te RPM and sends this directly to the ECU and the diagnostic connected directly to ECU I would guess its one of theese which generates this faulty reading..? Alltough as engine runs smoothly otherwise, guess trigger or ECU cant be completely off..?
(Even with engine turned off, just with engine power on we can see the diagnostic showing 76RPM..?)
Has anyone seen this kind of issues before..?
Is this something to be worried about as assumably the fuel injection as well is based on RPM, and if the ECU gets a faulty RPM signal I guess it will mess up the fuel mixture..? (dont want the engine running lean again,/)
Thanx for any help
- Engine runs clean and much smoother then before on idle and low rpms.
- Only strange thing we noticed while running steadily @ about 4000 rpms, we could see some strange rpm fluctuations on the diagnosic laptop. RPMs was wariyng from about 3900-4200, looking at the diagnostic. however listning to the engine it was running at a steady RPM, no rpm changes could be heard. So obviously there is something interferring the RPM signal?
- at one stage rewing the engine while trying to get on plane we could see the RPM readings on the diagnostic showing all the way from 1000- 9000 RPM!?, and the engine completely stalling out. This 9000rpm reading offcourse cant be a real one.
-assuming its the trigger (crank position sensor) which records te RPM and sends this directly to the ECU and the diagnostic connected directly to ECU I would guess its one of theese which generates this faulty reading..? Alltough as engine runs smoothly otherwise, guess trigger or ECU cant be completely off..?
(Even with engine turned off, just with engine power on we can see the diagnostic showing 76RPM..?)
Has anyone seen this kind of issues before..?
Is this something to be worried about as assumably the fuel injection as well is based on RPM, and if the ECU gets a faulty RPM signal I guess it will mess up the fuel mixture..? (dont want the engine running lean again,/)
Thanx for any help