lerf

Recently I have replaced the 2 coil packs and the car ran like a charm for a month. Now Cylinder 6 is misfiring and I am afraid it is the coil pack again? or the modular plate it sits on? Only Cylinder 6 is misfiring.
Symptoms
-Only during 60% + Throttle
-Popping Noise if you continue misfire 2+ seconds (Smells like firecracker).
-Engine Diagnostic (Cylinder 3 Misfire)
-Situation worsens in rainy situations (Poured rain about 30 hours ago.)

++ Replaced 3/3 Ignition packs (less then 2 months ago)
++ Brand new engine (30k miles)
++ **THIS SAME PROBLEM CAUSED MY LAST ENGINE TO BLOW, Therefore it has nothing to do with the engine but rather anything besides it.

jim ravencraft

Hi,
i would start with checking the following:
Plug
plug wire/short/ground
check voltage/resistance/coils/injectors
vacuum leak
timing
dirty injectors
clogged fuel filter/bad fuel
good luck and let me know if i can help you in the future.........
Have a blessed weekend.......captain jim

MrElectric03

iTrader: (71)

Can be many things, I had a bad front 02 sensor cause a similar issue.

lerf

Another Symptom: The car is hard to drive past a certain speed (~55MPH), For example it only has 55 MPH worth of horsepower or whatever, if I want to go faster then that, the only way is for it to let it misfire, but that's how I blew my engine. For Example, going in a zero slope rode, I can slowly accelerate to 50 MPH, but for example, if I try going up a hill I can only go ~40 MPH before it starts to misfire. Thinking a bad coil pack #3 but it's brand new. Also, for the O2 Sensor, did it read out Misfire cylinder 6?

LS6427

iTrader: (2)

You could have an electrical fuel injector issue. If just one of them has an issue, it can take out all 4 on that side. If you're confident that the coil packs being new is not the issue and they are getting their sufficient power, the spark plug wires are good and NONE of them are touching ANY part of the metal exhaust manifold piping and the spark plugs are good (ceramic part not broken) and lastly......the fuel injectors for those problem cylinders are not leaking of dirty.....

Check the elcetrical stuff for the injectors.

.

O2Form

1st of all WHAT IS THIS? How about a little info on your car! is it a six or a 8 ??????? what year etc! GEEZ

Everyone get out theor crystal ball and help this guy!

2nd thing is you actually drove it like this till the engione failed and you are TAKING a chance driving it like this AGAIN??????


TAKE IT TO A DEALER!

hmmmm lets see whats cheaper guessing at whats wrong and blowing the engine OR taking it in for service..............hmmmmmm guess this is a brain twister!

lerf

Okay, 3.8k 1999 Pontiac Firebird. Just switched the spark coil packs, they are fine. The spark plug wires are not the problem, recently it was reading cylinder 3 misfire before I got the coil packs replaced, replaced the coil packs and the car was sound, now with the rain its **** again, misfiring and everything.

LS6427

iTrader: (2)

Check for exposed/frayed/damaged wires for the 02 sensors. When it rains that will cause your issues if you have messed up wires.

.

jim ravencraft

Hi,
this may not be your issue but in years past i've seen restricted exhaust greatly reduce power. Muffler/exhaust collapse internal or cats if you have them. A vacuum check will tell you the answer as the needle gradually drops to zero or a low reading. Have a blessed week and good luck.......captain jim

O2Form

The newer v6 fbodies have ignition problems, more than i'm willing to go into here. Go search a v6 site for some answers. Prolly gonna need to replace the wire harrness that feeds the ignition package etc.