Checking crank sensor function?!? Arrrrghh!
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Checking crank sensor function?!? Arrrrghh!
Okay, I spent quite a bit of time yesterday trying to get my new motor started with no joy. After several attempts at cranking her over I finally pulled a couple of the spark plugs. They were bone dry. It looked like there was no fuel. After a bit of flailing around and double checking alot of crap I finally decided to start monitoring the cam and crank sensor readings using the AEM EMS. The EMS tells me that it's getting a cam signal but nothing on the crank sensor.
It was late last night but it looks like the wiring leading to the crank sensor plug is good. I've got good ground, a good 12V supply and the 5V signal from the ECU going to the sensor looks good too. Just to make sure I wasn't completely out of my rocker I also checked the crank to valve timing and the orientation of the cam position sensor. Both appear to be perfect.
At this point it appears that I've got a bad crank sensor. The diagnostic procedure to confirm this as outlined in the service manual involves using an oscilloscope. I don't have one of those in the toolbox yet... Before I go pulling crank sensor out, does anyone know of a relatively simple diagnostic check that I can perform? is there a way that I can "excite" a crank sensor before installing it to make sure it's good and the EMS can read the signal? It seems that I should be able to since it's a simple Hall effect sensor.
It was late last night but it looks like the wiring leading to the crank sensor plug is good. I've got good ground, a good 12V supply and the 5V signal from the ECU going to the sensor looks good too. Just to make sure I wasn't completely out of my rocker I also checked the crank to valve timing and the orientation of the cam position sensor. Both appear to be perfect.
At this point it appears that I've got a bad crank sensor. The diagnostic procedure to confirm this as outlined in the service manual involves using an oscilloscope. I don't have one of those in the toolbox yet... Before I go pulling crank sensor out, does anyone know of a relatively simple diagnostic check that I can perform? is there a way that I can "excite" a crank sensor before installing it to make sure it's good and the EMS can read the signal? It seems that I should be able to since it's a simple Hall effect sensor.
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If you get to it tonight make sure that you did not put the crank timing plate on backwards, if you did then it will not slip through the opening for the CAS where it is supposed to rotate through, but will instead eat the CAS up. I had mine on backwards and figured it out oncw I had set the timing and was turning the engine over by hand to check everything out. (thank goodness) I found it to be a pretty easy mistake to make at least.
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Originally Posted by joeycoates
If you get to it tonight make sure that you did not put the crank timing plate on backwards, if you did then it will not slip through the opening for the CAS where it is supposed to rotate through, but will instead eat the CAS up. I had mine on backwards and figured it out oncw I had set the timing and was turning the engine over by hand to check everything out. (thank goodness) I found it to be a pretty easy mistake to make at least.
At least I was able to test the spare sensor had on hand by passing a steel between the sensor gap. Using the EMS as an indicator of the circuit condition I was able to immediately see the blade pass through the gate confirming the operation. Hopefully the swap won't take too long. I want to fire this thing up!
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Update: I swapped out the crank sensor and the motor fired up first try. I almost had tears in my eyes it was such a beautiful sound.
Also, I'm not sure if this is an original thought but it is possible to swap out the crank sensor without following the entire process outlined in the service manual. It involves removing the connector housing and fishing the new sensor wire up through the channel it lives inside. It took me about ten minutes to remove the connector and fish the new wire up through. Although the wire isn't clipped to the back cover plate using the little plastic clip, it's still secured by the metal clips top and bottom and doing it this way saved me hassle of pulling the power steering pump and about 2 hours of labor.
Also, I'm not sure if this is an original thought but it is possible to swap out the crank sensor without following the entire process outlined in the service manual. It involves removing the connector housing and fishing the new sensor wire up through the channel it lives inside. It took me about ten minutes to remove the connector and fish the new wire up through. Although the wire isn't clipped to the back cover plate using the little plastic clip, it's still secured by the metal clips top and bottom and doing it this way saved me hassle of pulling the power steering pump and about 2 hours of labor.
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Originally Posted by propellerhead
Okay, I spent quite a bit of time yesterday trying to get my new motor started with no joy. After several attempts at cranking her over I finally pulled a couple of the spark plugs. They were bone dry. It looked like there was no fuel. After a bit of flailing around and double checking alot of crap I finally decided to start monitoring the cam and crank sensor readings using the AEM EMS. The EMS tells me that it's getting a cam signal but nothing on the crank sensor.
It was late last night but it looks like the wiring leading to the crank sensor plug is good. I've got good ground, a good 12V supply and the 5V signal from the ECU going to the sensor looks good too. Just to make sure I wasn't completely out of my rocker I also checked the crank to valve timing and the orientation of the cam position sensor. Both appear to be perfect.
At this point it appears that I've got a bad crank sensor. The diagnostic procedure to confirm this as outlined in the service manual involves using an oscilloscope. I don't have one of those in the toolbox yet... Before I go pulling crank sensor out, does anyone know of a relatively simple diagnostic check that I can perform? is there a way that I can "excite" a crank sensor before installing it to make sure it's good and the EMS can read the signal? It seems that I should be able to since it's a simple Hall effect sensor.
It was late last night but it looks like the wiring leading to the crank sensor plug is good. I've got good ground, a good 12V supply and the 5V signal from the ECU going to the sensor looks good too. Just to make sure I wasn't completely out of my rocker I also checked the crank to valve timing and the orientation of the cam position sensor. Both appear to be perfect.
At this point it appears that I've got a bad crank sensor. The diagnostic procedure to confirm this as outlined in the service manual involves using an oscilloscope. I don't have one of those in the toolbox yet... Before I go pulling crank sensor out, does anyone know of a relatively simple diagnostic check that I can perform? is there a way that I can "excite" a crank sensor before installing it to make sure it's good and the EMS can read the signal? It seems that I should be able to since it's a simple Hall effect sensor.
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Originally Posted by DynoFlash
congrats !
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