DOC Henry

This is a list of things done in an attempt to get rid of a p0304 at idle only. Plugs, wire set, ignition coil, cap and rotor, distributor, sequential injection, fuel pump. All have had no effect on the code. Code comes on at idle, yes it does idle rough. Ac Delco plugs, Duralast brass cap and rotor, Duralast wire set, Compression test gives 140-145 lbs in 2,4,6 cylinders. Any ideas?

ericn1300

I had a cold start idle problem that progressed into a full blown cold start misfire and stalling. turned out to be the upper distributer shaft bearing was going out. No simple fix, just R&R the dist. if that's the problem.

dewaynep

This probably won't help your p0304, but the first thing I would do is get rid of that Duralast cap and rotor and put in an AC/Delco set. At the very least you will want to get an AC/Delco rotor. When you get the new rotor, compare it to the Duralast one and you will see the electrode is about 1/8" shorter on the Duralast. Caused me quite a few headaches chasing a random missfire until I decided to change out the brand new Duralast cap and rotor with an AC/Delco from the dealer.

Blue Bowtie

Can you log the injector PW for each cylinder at idle?

DOC Henry

Don't have the equipment to do pulse width test, but the whole injector setup was changed because of a stuck poppet.

DOC Henry

Thanks for the input. Before I take it to the dealer I will put on an Ac/Delco cap and rotor. Just doesn't seem reasonable to manufacture parts that don't work when they are brand new. Duralast/Auto Zone