[tiredofcarproblems]

In need of help. We have a 99 Pontiac Grand Am SE 2.4 liter the car was not getting enough power while driving down the road from work and was only going up to about 12 to 1400 RPMs after losing power pulled over on side the road and shut the car off but now the car will not start back. We have tested it with a code reader and we get po300. With this misfire code we have changed just about everything possible. We started with the throttle positioning sensor and nothing. we change the camshaft sensor and nothing. we change the crankshaft sensor and then nothing. We also change the coil pack, spark plugs, and fuel filter. While changing the fuel filter we check to see if the fuel pump have pressure and it did. We also had the ECM tested for different times and it was good so we did not change it. We have check the relays and fuses and they all work. The fuel pressure regulator is good. We even reset the system lockout and still have nothing this is something we read and one of the forms that could have been a problem with Pontiacs. We are literally to our wits in and cannot figure this out the car will start to turn over but it will not crank and when we try to turn the key a second time it'll do the same thing but much worse than the first. Does anyone have any idea why the car will not crank