2002 Grand Am turns over but won't start. Code#'s inside...

[mycohopper]

2002 Grand Am, 140K miles, 4cyl, automatic.

AutoZone code reader pulled up 2 instances of code# P0300 "Random/multiple cylinder misfire". The car idled VERY rough before it stopped cranking at all. Engine would bounce up and down for 5 seconds then die. Now the car just tries turning over but doesn't start. Fuel pump was replaced less than 20K miles ago. We're at our wit's end with this issue. Where do I start looking for clues????

 

[Goatman]

Sounds like the fuel system is clogged causing the missfires
also was the filter replaced at the same time as the pump?

 

[mycohopper]

Sounds like the fuel system is clogged causing the missfires
also was the filter replaced at the same time as the pump?

Yes it was. But I pressed my knife against the fuel-rail port and gas spurted out after we had tried cranking it a few times. It only took a couple of seconds before the gas would just dribble out but each time we tried cranking it after that, the pressure would build back up so that when the port was pressed in, the gas would spurt out kinda hard, then lose pressure and drip.

 

[[ChaosweaveR]]

Those are the only codes coming up? The L61 (Ecotec) isn't really know for fuel issues. I'd suspect either a sensor regulating the AFR (LIike the upstream O2 sensors, IAT, TPS, MAP etc) but I'd have it plugged up to a scanner to see why it's losing fuel pressure, get real time data. Good chance it's not a clog, but possibly the ECM isn't getting a reading on sensors, and therefor, not conducting a proper AFR.

______________________________

 

[mycohopper]

Bump.

Need help!

 

[melsg5]

try placing a pressure guage on the port