1995 Altima won't start - Battery good, starter good. Changed spark plugs. Changed wires. Changed distributor cap & rotor. Performed spark test (spark looked weak, but is present at plugs & coil). Tested coil primary (1.4ohm) & secondary (13.43ohm) resistance. Tested power transistor resistance (had resistance where it should). Checked fuel pump fuse, good. Trial & error fuel pump relay with cooling fan relay 1 (switched & tried to start, no start). Disconnected fuel line from filter to rail, had pressure (slight) & fuel. I can hear the fuel pump kick on when I turn the key on. I will purchase a pressure gauge tomorrow to test the fuel pump pressure. Can this be the camshaft position sensor? I put my ohm meter on this and got resistance but not sure what the results mean. Can this be a "weak" coil? Can this be a "weak" fuel pump? Should I check the injectors? What if any other checks can I do? Sensors, etc...Any knowledgeable advice would be greatly appreciated. Thank you.
Wow, sounds like you dove into this pretty hard. I would check the communication to the ECM, make sure you have a signal to the main computer. Camshaft, crankshaft position sensor, could be a possibility. If the car has been sitting for a while, I would make sure the fuel injectors were not leaking into the cylinders flooding it at potential start. Bad Gas?
Basing these findings on a 1995 Altima SE, the readings for the primary coil should be 1.0 ohms and the secondary 10,000 ohms.
It seems like you know how to check everything, but you need to have a book to understand what those readings mean. Without that, you would be guessing at the problem.
Another thing to know is that if the engine is spinning fast when you try to start it, it could be a broken timing belt.
Most likely if the camshaft position sensor is bad it would be setting a code and the check engine light would be coming on.
While it's great to be able to check all these things, if you don't understand what the readings mean, then it's time to get help from a technician.
You've gathered some great information to give them and it will make their job easier. Good luck.
〉 Answered on Jan 29th, 2008 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines