Tothemax

I have a sct 5* 91 octane performance tune installed and the plugs were gaped at .030 right before I installed it. Any reason to pull them and regap?

The truck seems to run fine and it gets decent mileage (could always be better). Only Issue I notice is a "miss" when its warming up at idle. But that seems to be fairly common.

MGD

I dunno aboot common, but that sounds like what ol' Makuloco describes in his EB vidyas when talking aboot the intake valve accretion on the back side.

It sure ain't normal - and I don't think dropping 0.002 is gonna make any difference. But - it IS cake to do, so won't hurt to try.

What's 5* recommend?

We talking fresh SP534's?

MGD

Tothemax

I thought it was normal. Read in a could other misc threads about guy experiencing the same thing. Goes away once the motor is warm.

I cant remember what 5* recommends. its .028 or .030. Ill have to look that up again.

Yes Brand new SP534s.

Tothemax

Not my video but pretty much what I am experiencing at cold idle:

SkiSmuggs

I found that when towing heavy, the plugs can start to miss at 20K, but 30K is about as far as I could trust the plugs with spirited driving.

Sirikenewtron

Mines doing the same, no tune, changing plugs in the next day or two, ill see what happens after that

crazydubc

.002 wont make much difference but when I checked mine when I did my tune, it was off by .01... I now check them every 10K miles now out of OCD.

Tothemax

I figured it wouldnt but thought Id ask.

Sirikenewtron

Changed plugs, old ones didn't look to bad but we're all gapped right around .035.
Put new plugs in sp-534's gapped at .030 and idle is much better!
5 star recommends the sp-534's gapped at .035 btw but I hear a lot of guys running tunes gap them to .028