Hi everyone, non-opti Ignition Problems

[98 'Bird]

I thought it might be appropriate to reintroduce myself since I haven't had a post or question in some time, though I'm always on the site searching threads and finding great information, without starting new threads for the sake of not cluttering the forum with stuff that's been covered ...Zaino...?

So I have a V6 5-spd that has 57,500 on the clock. Last summer I had a couple problems, (replaced leaky waterpump, ordered OEM from trademotion, alternator died, had that rebuilt) and it looks like this summer might be a repeat.

A couple weeks ago, one day out of nowhere I started the Bird and noticed a miss that quickly got bad once I started driving. After a few miles SES finally comes on. I drove it to my uncle's, ran the OBD and found a misfire on #5. Took it to my mechanic to have the original plugs replaced (not a job for me) and as suspected, he also found that the cylinder 2 & 5 coil and gone bad. The plugs were also "dirty as anything". He changed the plugs out, and just the one bad coil from the pack. I thought he would've replaced them all.

So it ran fine at first, but then I noticed a less steady idle, and then what feels like a miss or hesitation around half throttle. Today I started the car in the middle of a rain storm (more like a hurricane) to move it in the driveway away from trees as some had already fallen down. You central NJ / Philly area guys might have gotten some of this. Anyway, this time I felt a more noticeable miss at idle (rain?), no SES though, yet.

So I'm thinking of buying 2 new coils identical to the new one, which is a Standard, and relpacing them myself. OR maybe I should just call the mechanic back right away in case something got messed up. What should I do? Should the entire coil pack have been replaced once the first coil went bad? I don't think any wires were replaced. Also, I had the fuel filter replaced. Thanks in advance for any help and suggestions.

[Injuneer]

Before you start playing "parts replacement roulette" in a blind attempt to solve your problem, have it scanned again. Not all codes turn on the SES light. Using a scanner with GM Enhanced Parameters, its possible to access the actual misfire count, by individual cylinder. That may point you in the correct direction.

How old are the ignition wires? How old were the plugs that needed to be replaced?

You also need to figure out why the plugs were "dirty as anything". What kind of "dirt" - carbon? The mechanic should be able to tell you what he found, and what he thinks the cause is. If it was carbon, find out if its running rich. That may be the result of the misfires, a leak in the exhaust system before the O2 sensors, or faulty O2 sensors or wiring.

Just because a single coil went bad does not mean all three need to be replaced.

[98 'Bird]

Just because a single coil went bad does not mean all three need to be replaced.

Thanks for clearifying, Fred. I couldn't find a straight answer on that
no matter who I talked to.

How old are the ignition wires? How old were the plugs that needed to be replaced?

I believe the ignition wires are still original. I was surprised to see he didn't replace them along with the plugs, which were also original. Two years ago when the car had ~50k I took it in and inquired about replacing them due to their age. The guy there looked at me like I was crazy and said "they're 100k plugs". This was when I was having all work that I couldn't do myself done by the dealership. The Stealership!!!!! I thought I would've seen $$ in his eyes.

So maybe the age alone can be a cause of the "dirt" buildup??

[Injuneer]

The stock plugs, which are the correct heat range, should not carbon up or experience any other type of dirt. They will "wear", with the gap opening up a bit. The stock platinum plugs were intended to last 100K miles.

I don't know what plugs they used in the V6, but the AC/Delco plugs used in the LT1's were notorious for losing the little platinum pucks off one or both electrodes, opening the gap up until the coils simply couldn't fire them any more. When that happens, the voltage looks for a place to escape, and through the plug wire insulation, to another plug wire (cross-fire) or to nearby metal like the block happens. At that point the wires start to erode the conductor and eventually you need a new set of wires.

[98 'Bird]

My father spoke to a mechanic where he works who has had experience with the 3800. He said I should check the resistence for wire #2 which shares the same coil. Meanwhile I'll see if I can find any pending codes on the OBD.

I don't know how then to explain carbon buildup on the stock plugs.

Thanks for the info.

[98 'Bird]

Thanks

Hey, thanks for the help. My trusted mechanical and uncle agreed that coils are either good, or they're not. I had my wires replaced and no more missing! I just had a little trip on the PA tpike where for the first time ever (nearly 6 years of ownership) I floored her (I drive 'er pretty gently), and she took off! Sure no LS or LT but I was surprised. I still think there could be fewer vibrations at idle but then again, I'm anal.

[Injuneer]

Minor vibrations at idle could be dirty injectors. Have you ever used the injector cleaner that you add to the fuel?

Glad you're having more fun with the car now that its running better.

[98 'Bird]

Minor vibrations at idle could be dirty injectors. Have you ever used the injector cleaner that you add to the fuel?

Glad you're having more fun with the car now that its running better.

Actually... I was just looking into getting some Techron concentrate or BG 44K. They both claim to not only clean injectors and fuel system parts, but also carbon deposits on the valves and buildup in the combustion chambers. Have you ever used these?

Ever hear of Car Talk? I listen to the show. They're pretty smart guys... and funny. They've recommended these products specifically.

Oh, but also to answer your question in short, I have used an injector cleaner - a year ago. I think it was your typical STP stuff. It might be time to use a cleaner again but might as well use something more advanced. Not necessarily that Seafoam stuff; that kinda scares me.