legacycentral bbs

Hey guys, I'm a noob to this forum, so please be patient. I've just done a 20g swap with a 550 rob tune and a 20g Ecu, the whole thing. And it seems that I have a boost leak since it won't spool up past 14-15psi before it starts hesitate and buck, and once or twice now backfire. I turned the boost down to about 12 now, runs good but still every once and awhile will still hesitate and back fire. No CEL no nothing. Just changed plugs today with one step colder NGKs. I've already presure checked the whole system(FMIC) and held to mid 20s psi without so much as a hiss or leak. So I'm kinda stuck...
My buddy says it could be the factory BPV or waste gate actuator. He has the same set up with his wagon, and hits 18psi all day long.


Is there any other things I could check??
Btw I have no AFR gauge installed, but have clean yellow tops, and walbro pump, so I THINK it's not a fuel prob....but I don't know....... Frustration is starting to take over.

Any help or direction would be awesome, thanks.

I would recommend getting an AFR gauge to help diagnose things. If your intake held pressure during a pressure test it should be ok and you shouldn't have a boost leak. I would not recommend running colder plugs unless you are finding that the regular plugs are having issues and the electrodes are wearing prematurely.

Hopefully others have some additional feedback. There are some folks in your area that may be able to help if they are available.

Try the standard recommended plugs and gap them down a bit.

edit:
http://bbs.legacycentral.org/viewtopic.php?f=2&t=48133

Wow! Thanks for that link, I would have never guessed it was the gaps. I'll put some new ones in a see if it fixes it, thanks again!!

Wanted to say thanks Mike-Tracy the plugs seamed to do the trick. It would have took me a long time to figure that out, thanks again!!

Glad that's what it was!