Random misfire code....

[JPrince89_]

SO ONE MORNING I START MY CAR UP, 2005 BONNEVILLE SE 3.8 AND IT RAN HORRIBLE, NO PROBLEMS AT ALL PRIOR BESIDES REGULAR MAINTENANCE AND SUCH.. GOT CAR CODED, TECH SAID RANDOM MISFIRE.. IVE CHANGED SPARK PLUGS, PLUG WIRES, NEW COIL PACKS, NEW FUEL FILTER, NO VAC LEAKS.. WHEN ITS IDLING YOU CAN FEEL THE CAR "SHAKING" STILL.. I DROVE IT JUST TODAY AFTER CHANGING FUEL FILTER, CEL IS ON AND WHEN IM TRYING TO GET UP TO SPEED THE LIGHT STARTS FLASHING AND ITS SLUGGISH, WHEN I LET OFF THE GAS PEDAL THE LIGHT STOPS FLASHING, ALSO WHEN IM GETTING UP IN SPEED THE "SHAKING" STOPS UNTIL IM SLOWING BACK DOWN TO A STOP OR BARELY GOING 5-10 MPH... PLEASE HELP ME BEFORE I GIVE UP, I LOVE THIS CAR AND DONT WANT TO JUST PRETTY MUCH GIVE IT AWAY.

[dougtoth]

Try unplugging the MAF and see if that makes a difference.
You said you changed the coil packs.
Did you change the ICM also?
My 2001 had the same type of symptoms and it was the ICM.
I went to the junk yard and got an OEM from a car there.
The new ones you buy from China seem to be garbage.

[JPrince89_]

I have cleaned the MAF, But before that I unplugged it while running, and the car made no difference, which I hear the car is suppose to just shut down after a few minutes or so.. and no sir I haven't checked the IAC.. I Will check ASAP.. Will post shortly if I'm able to. Thank you!

[harofreak00]

Replace the ICM (ignition control module under the coils) with a good used OEM unit, not chinese garbage...not the IAC (idle air control valve).

[96 SSEi]

WHAT wires did you install? - I put delco wires from walmart in my 2000 and that caused the random miss.
if you get a flashing cel, there is prob a hard code to point to a cylinder - pull the codes again

[walnut777]

I JUST went through this same scenario.

It happened out of nowhere.
I am fortunate enough to have a friend with a snap on scanner. Code was p0300 random misfire.
My next step, go to cylinder contribution and see which cylinders are misfiring.

#3 and #6 were misfiring. I figured well probably just a bad coil since 3 and 6 share the same coil.
WRONG! Switched coils around and misfire stayed on 3 and 6.

I tested the Ignition control module using a couple methods I founds online. It tested good so I figured I was in for a treasure hunt to find the problem.

I went by the local junkyard. Grabbed a ignition control module. (they'll let me return it if it doesn't work) even though mine tested good so did everything else I tested.

I put my coils on the junkyard ignition control module. Installed it and problem solved!

[Jazzy]

I just went through the same thing. It was solved with a $45 junkyard ICM.