Faulty CKP Sensor?

[wellcraft34]

Cut out and replaced the corroded grounds, still no fire

[redlowrey]

I haven't got a wiring schematic on the 2012 df50, tell me how many wires go to the crank sensor and the cam sensor, the early engines had a hall sensor for the crank and an inductive sensor for the cam, which is the opposite for the bigger engines. The hall sensor will have three wires, power signal and ground, and the inductive two wires. Can you explain how you tested the injectors and how you know the iac valve is working. When you tell me how many wires go to each sensor, crank and cam, I will tell you how to test them.

Do these simple tests for a start, turn the key on, with a test light connected to ground, probe the pins on the coils both sides of the plug on all three coils test light should light. Do the same on the injectors, should be the same, test light should light, leave plugs connected. If the wiring is the same as the early engine gray should be ignition supply, if the test light lights on both sides of the plugs turn the key off and come back on the forum with the results.

[wellcraft34]

There’s 2 wires to the crank sensor and 3 to the cam sensor. For the IAC I pulled it out and when I turn the keyswitch the plunger moves, for the injectors, I pulled the fuel rail and cranked over and they sprayed.

[redlowrey]

Ok do those tests and get back with the results, the crank is an inductive and the cam is a hall sensor, it is obvious the cam sensor is working if it is spraying fuel. What country are you in. I will tell you what tests to do after you do those first tests. what sought of test equipment do you have.

[redlowrey]

I dont know specifics re the smaller engines white wire, and my river tinny with DF40A is presently stored at a friends place so I cant easily go and have a look.

However, as per Art’s sticky thread on the white wire, it should NOT be connected at the starter motor + terminal, it should be connected to the + side of the master battery switch, or, direct to the battery +.

Yes, it does make a difference. Its a slack shortcut taken by some installers to go to the starter + and it causes problems due to voltage drop. At the very least it is worth making the change to see if this is contributing to the issue you are having. Simple to run a temp wire.

'''''''''''''''''' That was Suzuki factory wiring until mid 2005 where they made some changes with the ecu so it could read low battery voltage at the ecu, where as before ignition supply came off the main battery cable at the starter solenoid through the sixty and thirty amp fuse to the main control relay, From there it went to the ignition switch and when you turn the key on it traveled back down the wiring loom through a gray wire to the main relay, now it is fused off battery pos straight to the ignition switch. The guy say's he has got 12.5 volts at the coils and injectors so unless they are ghost voltages, I would say that that voltage would be ok, but he should of cranked the engine and seen what they dropped to.

[wellcraft34]

I’m in US, I have a good multimeter and an inline ignition tester, and test light. So unplug the connection at the coils, and then check each wire in the plug with the key on?

[wellcraft34]

Ok, at the coil plugs with the key on, voltage at the grey wire nothing on the other two. Injectors, voltage grey wire nothing on second wire.

[redlowrey]

Having three wires on your coils you must have coil on plug ignition, with out having a manual for wiring colors, I would assume gray ignition supply, black ground, and maybe for the ecm driver control wires, blue orange, green and yellow or light green and red, it does not matter, these odd color wires will have five volts sent to them in sequence to ground the driver transistor in the module inside each coil to turn the coils on and off.

Use a low powered test light for this, an led test light would be good, turn the key to the start position after you connect the led light to ground and while the engine is cranking touch the connectors of each of the odd color wires, the light should be blinking on and off. This test will tell me if the ecm is receiving a crank signal. If the light does not blink go to your manual and look for the crank sensor pin numbers on the ecm They used to be red and black for signal, and black and white for ground, get a couple of the thin pins that you can slide down the side of the wire connectors in the ecu.
Set your multimeter on ac and crank the engine over and if the sensor is switching you should see around three or more volts, you need at least two volts peak to peak for the ecu to be able to read it. if nothing happens check your connections if still nothing disconnect the sensor at the plug and check again.

Have a look in your manual and see what goes to ground on that burnt pin, also connect your multimeter on low volts under 60mv connect black lead to ground red lead to the ground pin that is burnt and crank the engine and note what the voltage drop is. Also you need to explain in more detail about the starter hanging on when cranking.

[redlowrey]

I forgot, also probe the coil plugs black wire to ground with your ohm meter on each of the coil plugs, should be no resistance.

[wellcraft34]

I forgot, also probe the coil plugs black wire to ground with your ohm meter on each of the coil plugs, should be no resistance.

Getting 0.4 ohms on this, trying the other today

[wellcraft34]

I’m getting nothing cranking at the coils. At the CKP I’m getting really low voltage cranking, nowhere near 2 or 5. With the starter, when I turn the key to crank, the engine cranks but with keep cranking unless I turn the keyswitch to the off position.

[wellcraft34]

I should have said nothing at the coils on the third signal wire

[redlowrey]

Ok I think we better fix the problem with the starter first then go to the crank sensor, connect your test light up to ground remove the spade connector on the starter solenoid and put your probe into the spade and get someone to turn the key to the start position, test light should light, let key go back to the on position should go out. If the light stays on go to the starter motor relay there are four terminals if the same as early engine, green and yellow comes from the neutral switch, test light will light with the key in the start position, this will energize the relay coil through to ground inside the ecu, this will make the main contacts come together and switch battery voltage from the white fused supply to the red wire which goes to the starter. When you test the relay if the green and yellow wire stays hot when the key is back to the on position the problem will be between the key and relay.

If the relay contacts stick the starter will stay energized and when you turn the key off the relay coil will loose its ground inside the ecu. Was this problem there before you changed the wiring loom, I want you to that voltage drop test on the burnt earth pin the way I said in the previous post, and disconnect the crank sensor from the loom and test it when you fix the starter.

Surely you would have checked the ignition switch when in the start position, battery voltage on the brown wire then nothing with the key back to the on position battery voltage on the gray wire with ignition on.
How did you check the timing, plus have you done any thing else to the wiring any where I don't like that burnt ground wire, have a look on your schematic and tell me what gets grounded by it.

[wellcraft34]

I’m reading 5.9mV at the black ECU pin cranking. I unfortunately do not have the portion of the service manual that shows ECU circuit paths. Before the main harness was replaced, most of the time, it failed to crank at all. At the red spade on the starter, cranking light on and switch back to on light stays on. At the relay, the yellow wire with green stripe is hot with the key on.

[wellcraft34]

Unplugged, CKP putting out 3V