Intermittent firing

pontiac
bonneville

#1

just bought a 2002 bonneville sle 2 weeks ago .first few dats it ran great,then it started missing.dealer had his mechanic look at it.his diagnostics said #1 cylinder wasn’t firing. i replaced plugs and wires.no help.then mechanic said injector wire to #1 cylinder was dead.he messed with wires and got the miss out of it.today it’s back.any ideas


#2

Well, first you have to find out if it is still the first cylinder.

If it is still the first cylinder then I’d imagine that the wiring job for the injector harness wasn’t done very well. Check it out again.

If you find nothing there, before you actually spend any more money on anything check the compression.

If the compression is good and the wiring for the injector is good consider the possibility that the initial wiring problem may have damaged the injector. You can swap the #1 with another injector and see if the miss moves with the injector. This obviously involves pulling the codes as you go.


#3

If its the same cyl…then its the wiring job…look into that repair


#4

will definitely check compression.i have checked a cleared codes several times in last week.#1cylinder keeps coming up.