Hey guys, I know there's numerous spark plug threads but what's everyone running gap wise? I got step 1 colder NGK spark plugs and I'm a big turbo 6262 cobalt with a conservative tune. Idle is rough as **** right now so that's why I'm upgrading.

 

ur problem isn't ur spark plugs, go back to stock

 

Rough as in misfire rough or as in hunting for the rpm and timing rough?


What?

 

Stock plugs ACDELCO. Run a gap of .028-.030

 

I know this. I was inquiring as to the wording of his post (I must be getting old because seeing ur as a stand in for your screws with me), and for the OP trying to figure out if the rough idle is actually misfires or just hunting for timing which would be tune related. Running a 6262 could call for a step colder plug even on the LNF.

 

I agree with you. I'd say it's more a tune related thing. Can't hurt to go log idle a few times and adjust fuel trims accordingly. Mine needed adjusted a few times during the year due to temp and the E85 in my area adjusting to E70

 

I sent a video to my tuner and he said it sounds normal but on cold starts it sounds like I have stage 2/3 cams and it's on the stock motor. My stock spark plugs were about maxed out during tuning so that's why I'm starting with them.

 

I burnt that bridge
PTE 6262 DBB .63 AR
Southbend stage 4 clutch
Fidanza lightweight flywheel
Built 4.45 trans
Driveshaft shop stage 2 axles
Blah blah blah other ****

 

If you have HP Tuners do a log of your idle and see how far off the fuel trims are. Sometimes they get off enough that the idle hunts a lot.

 

This. And depending on how much time the tuner wants to put into getting someones idle to be perfect on the LNF (which can be a major bitch therefore the it's normal comment)

 

Still stock plugs. Iv run one step colder and my engine ran like crap. I run stock on zfr at 28psi and meth and they work just fine. Gap the to .028 though

 

the 6262 flows a lot more air than the zfr does.

 

I have 4 misfires guys lmao time for the spark plugs

 

Just 4 misfires? Or 4 misfire codes?

 

There's no extra load on the plugs at idle, if they're breaking up under boost that's one thing but the big turbo has no effect on cold start.

Get your tune straightened out or investigate why the rough running is happening. I'm all for putting new plugs in it but I don't think that's the cause of your issues.

 

P0300
P0301
P0302
P0303

Are all the codes I got currently

 

Get a log of the issues, cylinder 4 isn't misfiring, if the plugs were the issue all cylinders would have codes.

 

If it's not the spark plugs, coil packs are next on the list and if that doesn't solve it then I'm out of ideas

 

Clean the MAF, clean the MAP sensors,

Make sure all of your ground wires are well connected.

 

Spark plugs looked extremely bad, even with step 1 colder plugs it's still got 10 misfires

 

Who's your tuner?

 

colder plugs won't make a significant difference at idle. The difference is at high load.

If you're getting idle misfires a few isn't that bad depending on the time frame. If the car is running rough and misfiring then you need to get your tune looked at.

Secondary question, have you cleaned the intake valves and checked for boost/vacuum leaks? Both of those will make the car idle like complete crap

 

KP tuning is my tuner, it was dyno tuned about 2 weeks ago.

So the plugs were definitely shot, and on a warm idle the AFR (read on the interceptor) read from 13.7-15.3 which I would think that's it's not supposed to bounce around that much. Drive ability wise it runs like a champ but it runs really rich, which you can tell while doing a pull

 

It will bounce like that if the tuner doesn't know what they're doing, the lnf ecu is not a simple ecu to understand since it's torque based. Not trying to bash your tuner, just want your car running correct, if the swapped plugs only helped a bit you have other issues.

You need to do a boost leak test and look at your valves. How do you have your pcv system setup?

What numbers did you put down on the dyno tune?

 

It's running rich as ****, 11.2-10.8 AFR in wot

He said he tuned it conservative but I'm not even sure what it makes I never got a dyno sheet, 370-380 maybe?