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Alright so I would really like some help here guys. I am a diesel guy but not stupid when it comes to gas engines.

My gf's car (2005 cobalt lt 4dr AT bone stock 2.2) stopped running in mickey d's drive through yesterday. I was at work so a friend who is a diesel mec at a heavy truck shop and was a ford tech came to see if he could help. When he got there the car started fine for him 10-15 times and then would not. He pulled the codes and got the p0340. So after work in the parking while it poured rain I changed the crankshaft sensor. The car then started fine and ran home. I started it 10-15 times with no problem ran it the the rev limter and let it idle. I drove it home and parked it. After an hour I went to go start it nothing. I would crank but not fire. Pulled codes again and again got p0340. When I got up after taking her to work I tried to start the car it fired with no problem idled 5-6min and stalled would not refire. I then changed the plugs upon doing so I found the #3 plug to be loose and brown. I put new ac delco plugs in and it would not fire. I pulled the new plugs after cranking and found them to be damp and smell like fuel. I dried them off and put them back in still nothing. I know it should have a relearn done but would it fire sometimes and not others if all it needed was a relearn? I have not grounded the plugs to see if it is getting spark as I am home alone and have nobody to help me right now. ANY ideas would help so much guys. Thanks alot.
 

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Alright. Any ideas where to start with looking for the ground? Would a coil or a ing mod cause this? She had and ing mod problem 2 yrs ago that was hard to track down causing hard starts but never a no start. After it was replaced the issue was gone.

Food for thought the starter has been staying engaged after it fires for 3-5 sec. This problem started about a month or two months ago. It was not pursued as we are trying to by a house and many other things on our plates. It caused no problems other than it would sound like a free spinning starter after the start.
 

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I honestly dont know bud. Im not much of an electrician, and havnt even poked around down there. If it were me id start at the sensor, and check for bolted grounds along the wiring. Or if you have a mechanic buddy with an oscilliscope have check the circuit at the sensor and trace from there. I can check my service manual for diagnostic procedures for the code when i get home tonight, and post up tomorrow.
 

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So I found there to be no spark. But the problem comes and goes. I am leaning toward ICM. Does anyone know FOR SURE that you need to do a CASE learn after a crankshaft sensor replaced? At $80.00 I don't want to put a ICM in it to only learn I need something different. This car has had two ICM's one was bad the next went bad due to a bad spark plug, with the number 3 plug being loose and burned I feel it may have fried the ICM. I also would really like to know what would cause the starter to keep cranking after the car is started and key realsed, this may narrow the problem down.
 
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