Car misfire P0300, NEED HELP! PLEASE!
10-12-2004, 06:58 PM
#1
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Car misfire P0300 - Solved I have a problem with my Pontiac Trans AM 1999, LS1.
The car misfire on 3 cylinders, (4,5,6 I think it was) and sets code P0300 (Random misfire).
It goes well when I press the gas-throttle very slowly up to 5000 RPM, and slowly let it off.
But if I quickly press the gas-throttle only up to 2000 RPM, the car start to shake and misfire.
It start to flood the engine with to much fuel.
I have change or tried different on this things:
Sparking Plugs
Wires
Coil Packs
Crankshaft position sensor
MAF
MAP
Fuel Filter
PCM
O2 sensors, all 4
Injector cleaner in the fuel
Fuel pressure 55psi
Fuses Checked
This things I did before, but I doubt it can have anything to do with it.
1. Changed oil, oil-filter, coolant fluid, and PCV-valve.
2. The pipe/house that holds the PCV-valve was clogged with gummy from the pipe/house, it had worn out and “melt” down on some way. Maybe the engine sucked in some particle that was left in the pipe when I replaced the valve(?)
3. Changed some wires to the right-front-turn light, and shorten the wires. After that the right font turn light will not flash. Something with the BCM must have happened. All fuses are ok.
Please help!
The car misfire on 3 cylinders, (4,5,6 I think it was) and sets code P0300 (Random misfire).
It goes well when I press the gas-throttle very slowly up to 5000 RPM, and slowly let it off.
But if I quickly press the gas-throttle only up to 2000 RPM, the car start to shake and misfire.
It start to flood the engine with to much fuel.
I have change or tried different on this things:
Sparking Plugs
Wires
Coil Packs
Crankshaft position sensor
MAF
MAP
Fuel Filter
PCM
O2 sensors, all 4
Injector cleaner in the fuel
Fuel pressure 55psi
Fuses Checked
This things I did before, but I doubt it can have anything to do with it.
1. Changed oil, oil-filter, coolant fluid, and PCV-valve.
2. The pipe/house that holds the PCV-valve was clogged with gummy from the pipe/house, it had worn out and “melt” down on some way. Maybe the engine sucked in some particle that was left in the pipe when I replaced the valve(?)
3. Changed some wires to the right-front-turn light, and shorten the wires. After that the right font turn light will not flash. Something with the BCM must have happened. All fuses are ok.
Please help!
Last edited by DLS; 10-22-2004 at 05:39 AM.
10-13-2004, 02:54 PM
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I had that problem once and it was a bad wire to my 02, I even had it once when I had a hole in the exhaust cause my a/f bung fell out on the road somewhere, It was just like you were saying, Shaking all over the place
Look for frayed 02 wires/exhaust leaks
Looks like you changed the obvious spark plugs/wires etc.
You change the fuel filter lately?
Look for frayed 02 wires/exhaust leaks
Looks like you changed the obvious spark plugs/wires etc.
You change the fuel filter lately?
10-17-2004, 07:04 AM
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a/f bung? Where is that located? On the exhust.. ? Is that the same as the O2'sensors?
New fuel filter...
Can the IAT-sensor have something to do with the misfire?
New fuel filter...
Can the IAT-sensor have something to do with the misfire?
