Df50, stall at idle.

[Daviddf50]

Hello I have a 2008 df50 that wont hold idle. If the ckp is unplugged and btdc is 5 on computer it idles all day long, when ckp sensor in engine stalls.

I have.
Replaced iac valve
Replaced ckp cmp sensor.
fuel system checked injectors cleaned vst tank etc.
Pulled head of lapped valves.
Cleaned all earth battery terminals etc.

If anyone can assit i be truly gratful thanks Dave.

[redlowrey]

It sounds like the computer is having trouble reading the signals coming from the crank sensor, when you disconnect the crank sensor the engine will go into fail safe and use the information from the cam sensor instead, this will make the timing fixed at 5" degree's. For people like myself it is a simple procedure to check the crank sensor with an oscilloscope and look at the output to see whether or not it is correct or the problem is somewhere else.

Send back more information on the history of the engine, Will the engine run ok above idle with the sensor connected, if so run it on the warm up leaver to over 1000rpm and connect your timing light and see what the timing is and see if it is erratic or disappears or stays at around 15" deg if it runs ok check the setting on the crank sensor you may have it to far away from the flywheel and at idle the signal voltage is too weak.

[Daviddf50]

Redlowrey thankyou for your reply. The engine has 320 hours, boat is new to me so dont know any real history. The ckp sensor is brand new and correct air gap .75 engine runs great at over 1000rpm below 1000rpm it just stalls. I have cleaned all the earths etc, this thing has got me stumped. I have also changed ecu same problem. Thanks Dave.

[Daviddf50]

I have also check continuity from ckp plug to ecu pins and all good there.

[redlowrey]

mate before I can move on to the next test I need to know if your computer is in control, check the timing above 1000rpm then slowly return to idle watching what the timing light does eg whether it goes to 15 or 20deg down to 10 at idle before it stalls.
I don't think your problem has got anything to do with the computer or crank sensor after telling me this. Has the check engine light come on with any faults, and one more thing ,are you handy with a multimeter.

[Moonlighter]

(Apologies for jumping in here…

Red, do you have time to look at this one please? https://www.suzukioutboardforum.com/...300-making-oil

[Daviddf50]

I got the problem the luff key in flywheel had sheared, ave had the motor at local outboard mechanic twice, there was 28psi difference in bottom cylinder so i pulled head relapped valves, changed iac valve changed fuel tanks, cleaned injectors and i could go on. hopefully that is the end of the gremlins in the motor and this will help someone else. Thankyou redlowrey for your help.

[redlowrey]

Mate do the test with the timing light and then get number one on tdc compression and have a look and see where it is in relation the the timing mark on the cover