back coil pack on driver side not firing at all "need help"
07-26-2009, 09:14 PM
#1
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back coil pack on driver side not firing at all "need help" 
ive been trying for the past wee, the car runs like crap. it sputter real bad and the engine light blinks and it throws code p0300 rando missfire.. i pulled a plug wire and cranked the car up to see it it sparks... it does nothing im wondering if it might be somewhere in the harness.... 
07-27-2009, 12:07 AM
#4
OK, you have either a wiring problem, plug problem or a PCM problem, the latter being the least possible.
Go through the wiring harnesses and unplug/re-plug every plug between the coil and the PCM.
Each side of coils has power off a fuse so it's not blown as the other three on that side are working. The PCM triggers the coil by shunting to voltage low (ground) within the PCM. There's also a referance to low voltage (ground) in the PCM and a external ground.
Little more info on your car, your sig says nothing about it...
Go through the wiring harnesses and unplug/re-plug every plug between the coil and the PCM.
Each side of coils has power off a fuse so it's not blown as the other three on that side are working. The PCM triggers the coil by shunting to voltage low (ground) within the PCM. There's also a referance to low voltage (ground) in the PCM and a external ground.
Little more info on your car, your sig says nothing about it...
07-27-2009, 08:42 AM
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[QUOTE=Paul Bell;11971709]OK, you have either a wiring problem, plug problem or a PCM problem, the latter being the least possible.
Go through the wiring harnesses and unplug/re-plug every plug between the coil and the PCM.
Each side of coils has power off a fuse so it's not blown as the other three on that side are working. The PCM triggers the coil by shunting to voltage low (ground) within the PCM. There's also a referance to low voltage (ground) in the PCM and a external ground.
Little more info on your car, your sig says nothing about it...[/QUOTE
its a customer car im working on and its stock its just somehow it started doing this but i pull the other plug wires and crank the car..they all ark like they are suppose to ..when i back one on the driver side it does nothing like its getting no voltage at all or like it may not have a good ground but i figure it should have a good ground because they rest of them are wrokin perfectly
Go through the wiring harnesses and unplug/re-plug every plug between the coil and the PCM.
Each side of coils has power off a fuse so it's not blown as the other three on that side are working. The PCM triggers the coil by shunting to voltage low (ground) within the PCM. There's also a referance to low voltage (ground) in the PCM and a external ground.
Little more info on your car, your sig says nothing about it...[/QUOTE
its a customer car im working on and its stock its just somehow it started doing this but i pull the other plug wires and crank the car..they all ark like they are suppose to ..when i back one on the driver side it does nothing like its getting no voltage at all or like it may not have a good ground but i figure it should have a good ground because they rest of them are wrokin perfectly
07-27-2009, 09:34 AM
#6
Even though you pulled the plug wires, it still doesn't tell you if the coil itself is any good.
Take the coil itself off of #7 cylinder and swap it with another coil. If the problem follows that coil, then it is bad. If it stays at #7, then it's the wiring harness going into that coil. Start then by putting on a voltmeter and crank the car over and see if you are getting voltage to the harness.
Take the coil itself off of #7 cylinder and swap it with another coil. If the problem follows that coil, then it is bad. If it stays at #7, then it's the wiring harness going into that coil. Start then by putting on a voltmeter and crank the car over and see if you are getting voltage to the harness.
07-27-2009, 09:59 AM
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Even though you pulled the plug wires, it still doesn't tell you if the coil itself is any good.
Take the coil itself off of #7 cylinder and swap it with another coil. If the problem follows that coil, then it is bad. If it stays at #7, then it's the wiring harness going into that coil. Start then by putting on a voltmeter and crank the car over and see if you are getting voltage to the harness.
Take the coil itself off of #7 cylinder and swap it with another coil. If the problem follows that coil, then it is bad. If it stays at #7, then it's the wiring harness going into that coil. Start then by putting on a voltmeter and crank the car over and see if you are getting voltage to the harness.
