Faulty CKP Sensor?

[redlowrey]

What voltages were you getting on the ground wires also check the five volt reference wire on the throttle position sensor red wire with key on and cranking

[wellcraft34]

Noticed this morning that is the keyswitch is in the on position for a while, the IAC gets really warm to touch.

[wellcraft34]

Just shot it with an infrared thermometer, I turned the key off it was 155 F

[wellcraft34]

Resistance across the 6 pins check out at 30 ohms

[redlowrey]

You haven't said what the sensor ground voltages were with the key on, engine off, should be no more than 20mv, cranking 60mv, it is important that you check these voltages. Also the five volt reference on the throttle position switch, red wire should have five volts on it key on. You may have lost an ecu ground and it has put a load on other circuits trying to find ground. I think your ecu is reading the crank signal, but wont switch the five volt turn on voltage to your coils for a reason. That burnt ground plug on your ecu would not do that without a lot of current going through it, or not a good connection.

This is a long shot disconnect the tacho plug, the ground that goes through it may have been stressed and is touching one of the wires that goes back inside the ecu and that same ground goes to your emergency stop plate. The problem is going to be something simple that keeps getting over looked

[wellcraft34]

What voltages were you getting on the ground wires also check the five volt reference wire on the throttle position sensor red wire with key on and cranking

Ground wires were around 5mv key on and 28mv cranking. TPS had 5v key on and cranking

[redlowrey]

Are you 100% sure the loan computer works, has the engine been started since returning it and fitting it back on the engine. Those grounds are fine, the computer is receiving the crank signal , but wont supply the five volt turn on voltage to the coils for some reason. Can you check the coil plugs again use an led test light, key on battery voltage on gray wire, nothing on ground, nothing on the five volt switching wire. Cranking, battery voltage on gray wire, nothing on ground, blinking light on five volt switching wire.

When you said that the starter motor would stay energized when you let go of the key, how long would it stay cranking, indefinite, or for around four seconds then stop, In that capacitor ass, there is a diode I am wondering if it shorted, it could back feed instead of block, if the capacitor shorted, it would blow the fuse, if it open circuited there would be no crank, but I don't know what it would do with a shorted diode.

When you changed the wiring loom did that come with a capacitor in it, Under normal circumstances when you crank the engine as soon as the computer receives a rpm signal it will remove the ground on the starter relay.
Can you check this, with the key on you should have 2.5 volts on the brown wire at the switch.

[wellcraft34]

I still have the loaner computer on the engine, it’s brand new from a dealer friend, never used. Rechecked coil wires, everything was good except no blinking light when cranking. The starter will crank for around 5 seconds then stop. When the engine harness was switched the capacitor came with the other one, hard wired into it.didnt have my meter to check the brown wire but I’ll do it tomorrow morning

[redlowrey]

I know you said there is no kill switch and it shouldn’t crank over if activated but have you checked the wiring to make sure it is not grounded any where

[redlowrey]

I know you said there is no kill switch and it shouldn’t crank over if activated but have you checked the wiring to make sure it is not grounded any where

Did you un plug the tacho, and try it, if it had an internal short inside, it could back feed into the ecu, also pin 16 is the terminal for the emergency stop with key on should have 5 volts on it blue and red.

[wellcraft34]

Did you un plug the tacho, and try it, if it had an internal short inside, it could back feed into the ecu, also pin 16 is the terminal for the emergency stop with key on should have 5 volts on it blue and red.

This rig doesn’t have one currently, I never reinstalled it after I originally took it out

[wellcraft34]

I know you said there is no kill switch and it shouldn’t crank over if activated but have you checked the wiring to make sure it is not grounded any where

I haven’t, I’ll look into it

[dimarmarine]

hey mate did you solve this isssue? im having same problem cheers