rough idle 2.4l gm

[fenixsaurus]

i have rough idle i have code p0300 i have replaced the plugs i have checked and put new filter and injector cleaner in and still got problem and seem everything i do do helps a little i also put new o2 senor only thing left is plastic part under cover where also module is and coils if anyone has any ideas it would help

Topic

[Kevin Criswell]

Is this the “quad-4” style engine?

If it is, this part is most likely your problem

It breaks down and allows crossfiring to occur, it is a VERY common problem

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[Kevin Criswell]

BTW it is called a “coil cover” usually costs less than $30.00

And whenever I had a quad-4 that had random missfires, 99% of the time it was the cover, inside the cover are routed electrical contacts that make contact between the boots on the spark plugs and the terminals on the coil. Over time the plastic breaks down and the voltage is allowed to “jump” between the contact strips and makes the engine start to missfire like crazy.

http://www.automotiveforums.com/t644772-p0300_random_misfire_2_4l_quad_4_solved_.html
As you can see the plastic cover is a very common failure point in the quad-4

[fenixsaurus]

thats what dad said hes ford med ill do wires and that part and see what happens

[Kevin Criswell]

Lets us know if that fixes it.

[Author]

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