Hey all,

I have had an engine code on for a while and a the runner had stalled out on my twice, cant remember the number but it was for one of the banks running lean. After talking to several of my mechanic buddies I assumed it was the spark plugs, at 212,000 I dont think they have ever been changed. Long story short I swapped out the plugs and wires and now the truck runs but if I give it any gas it starts sputtering and misfiring( I believe its a misfire at least). It seems that it is much worse when cold and it eventually warms up and stops doing it for the most part. I double checked my work with the plugs and i used ngk's with oem wires. I also changed the fuel filter after the fact, with no change.

Any thoughts on what it could be and how to test it? My thoughts are possible coil pack or tps?

Any and all help is appreciated,

Thanks.

you gapped the plugs right?
and the wires are all fully seated?

Lean code is normally vacuum leak, bad or dirty MAF sensor, or bad O2 sensor. Could possibly be related to fuel system, injectors or pump. Spark plugs won't cause a lean code. I take it the misfire was not present before the plug change? (besides misfiring so badly it stalled that is...)

Correct, with the exception of the 2 stalls she ran fine. I cleaned the MAF and checked for vacuum leaks and didn't find any. I also replaced the gas cap. The more I read the more I think TPS but I really dont know. Would temperature affect the TPS? because It gets better as it gets warmed up.

oh and yes the plugs were all pre Gauged and all the wires were seated. Although how tight do the wires under the coil packs usually sit? because they all felt the same but were very easy to remove. if that makes sense.

I think your previous lean code was for a different problem. Maybe cleaning your MAF took care of it. If it comes back I would replace the pre cat O2 sensor unless it's been done recently. I think your misfire problem is related to the plug change. Something must not be connected good like Nevada said. Did you reconnect the ground on the drivers side by the diag port? If you disconnected it that is.

are you plug wires on the correct spark plugs? i know dumb question and kinda hard to mess up of these motors but just asking.

I know you said you double checked but this diagram has helped at least two guys who said the same thing...it is really easy to miswire.

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IDK how that could be, unless something is faulty. I did the plugs yesterday, Using ngk's and duralast wireset. I started the car and it idled fine, but I didnt go anywhere. Today I jumped in it and started it, again idle is great, but then I went to drive it and it had no go, and was shuttering, I drove around the block a couple times and it progressively got better to the point where it was hardly noticeable. I did some research and found I had gaped the plugs incorrectly and that the wireset could be an issue. So I got a new set of plugs and the OEM wireset and re installed everything and it has the same issues. I am no mechanic but I like to think I am capable of doing spark plugs right, at least the second time around.

And if it were spark would it get better with time/as temps go up?

oh and yes I remembered to reconnect the ground.

Sorry for so much info, just want it to be clear whats happening.

Thank you for the diagram, I will double check in the morning if they are mixed up, although I really dont believe they are (OEM wires come pre clipped so the lengths are in the right order).

it does sound like a spark/ignition issue. high resistance, or a bad connection somewhere. causing the spark to short out before getting to the plug.

IF there is such a problem, it will show up when cold, or under load.

okay. I will double check everything. how tight do the coil packs sit onto the spark plugs? because this is the only thing I can think that could be causing an issue. they are much looser than the wires on the drivers side.

Did you gap the new plugs too? Dual grounds right? I don't believe you need to gap them, they are pregapped. I didn't gap mine and they've been great.

You have the coil packs bolted down right? There's a bolt on each one.

I did not adjust the gaps on the new plugs. They are the correct NGK plugs, dual tips. I checked a couple and they were spot on.