2005 sentra 1.8 no start

[rlervin24]

I have a friend with this 2005 Sentra that is now in a no start. She first complained of a problem when it would rain. She said if it rained the car would not start. It would spin over fine. After a while the car would start but would sputter and misfire real bad. Eventually this would clear up and the car would run fine. I went and pulled the codes and the only thing I found was a P0300 for a random misfire from where it was sputtering. The car now will not start. It still spins over fine. I have good injector pulse with a noid lite. I pulled the plugs and checked for fire and noticed a real weak orange spark at the plugs. Not just one but all of them. I have asked some guys I work with at the shop about weak spark on coil-on-plug systems and they can't really say what it may be. I have heard everything from the CKP sensor to the ECM. Is there any good way to check this problem out? I had a problem like this on a 1995 Maxima and found metal flakes on the CKP sensor in the bellhousing. I cleaned the metal off and replaced the plugs and the thing cranked up and has been running ever since. I thought of doing the same thing to this thing due to the mileage (98000) but I can't seem to find the CKP sensor and didn't want to waste the money on the plugs if not needed. Anyone seen a problem like this before?