Timing/Octane question

[Stu_486Fitter]

It wasnt the rev limiter. Like i had said it felt as if it was missing..but it was NOT all the time. Just sometimes when I would drop into passing gear. Truck would be warmed up so i know it wasnt the usual break up from a cold engine.

I just got back from running it with the timing advanced 2.5* and it ran fine across the board. Just a touch more "ummph".

Back to the said issue...was going to do plugs until my mech. buddy caught me with a socket in hand and told me to STOP. I didnt know then of the lovely spark plug phenomenon of the 3v's. Thought to myself it could either be a fouled plug missing or a bad coil..but after speaking to a few people i personally ruled those out because it was intermittent....then came the octane switch and i havent seen it since

[Stu_486Fitter]

Oh yeah and I forgot to say we tried to read the CEL to see if it actually WAS a miss but nothing was stored in memory. Kind of makes it tough to diagnose...but this was all happening almost 6+ months ago

[ticopowell]

IMHO I think it would be best to go back to 87 octane, or try the 93 octane tune to see if it happens again. If it doesn't then you are probably going to be fine with a custom tune, but if it does I would get the problem fixed before possibly making it worse by doing a custom tune. just my 2 cents

[Jackpine]

Going back to 87 octane gas is a good suggestion, but with the CAI, I'd stay away from the Level 3 tune until you get a custom tune designed for that combination.

Actually, though, with a commercial CAI, you should not be doing any WOT runs until you DO get a custom tune. Those things are not going to give your engine a correct A/F mixture at WOT and you risk causing damage due to the mixture being too lean, which could also cause a "miss".

- Jack

[Stu_486Fitter]

Yeah thats why i have been running the 87t for now. The problem ocurred way before the intake was installed and before i got on the forums and read about the gotts mod. Maybe the next tank ill fill up with 87 and see if the problem comes back. Any ideas of what may do it? Maybe a coil? Maybe a fuel filter?