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I bought a used 06 Altima 2.5L and it had a check engine light on. The diagnostic read (P0300) a random misfire with no specific details. I’ve checked the coil packs and replaced the anomaly, I’ve replaced the cam and crank sensors also. I even put gasoline directly into the intake to rule out fuel issues. Still won’t start. I need help!!??
Engines running need 3 things. Air, fuel and spark. To some extent the fuel needs to be the right quantity (a little too much - like the suggestion of spraying starter fluid) is OK to run. As for spark, it needs to come at the right time (hence crank and cam position sensors). Air is pretty simple and almost never lacking. Fuel, make sure the computer is work (scan tool reports no problems) and you have pressure on the rails. Most/Many fuel systems have a shrader valve to test fuel pressure. Fitting like a tire air fill - poke it with a small screw driver and gasoline should squirt out. As for spark. Assuming the computer is good, there are various tools that can detect spark. One last thing. If the car fires up for a few second, then dies. Consider the possibility of a clogged catalytic converter. A missfire (your earlier problem) could have sent raw fuel to the converter which processed it (burned it) and overheated - internally melting, forming a clog. Since you fixed the spark issue (hopefully), just replace the converter. If the car fires for 1 second and dies (instantly). Look for a sensor malfunction. Cars with MAF sensors. Essentially the computer detects no air-flow and puts in the appropriate amount of fuel (which is zero -for zero air). Some cars you can unplug the sensor and the computer will estimate the amount of fuel needed - it just wont run as smooth or efficient and throw a check-engine light error.
@flexnyo “I’ve checked the coil packs and replaced the anomaly” let us know how you checked the coil packs and what anomaly you replaced. You also want to let us know if it ever started after you “replaced the cam and crank sensors also.” Any engine needs three things to work: Fuel, Air, and Spark. Seems like you are missing one of those. Since you already tried starter fluid etc. it sounds to me like you do not have a spark (or proper spark due to timing issues etc. You need to check for that first.
