Lately since I got my MBC I have been trying to run 21-22psi and whenever I get on it at wot it will just buck or feel like a backfire. If I run 19psi it is rock solid. I changed my plugs yesterday but left them at the gap they come as. The plugs are the bpr8's. I have gotten a cel once after the backfire but I do not have a scan reader to know what popped up.

whats going on?

 

BPR8ES I've noticed have a lot of gap variance. Mine have been factory gapped anywhere from almost touching the elctrode to ~0.45, so don't just toss them in without gapping them. You'd be amazed at the change in throttle response just from properly gapping your plugs.

Anyway, you are hitting fuel cut from what your computer thinks is an overboost condition. If you do this a few times within a certain timeframe, you will get an overboost check engine light. 22psi = ~1.5 bar, and that's roughly where I was getting fuel cut before my flash.

So...don't run high boost until you get a bigger fuel pump and a tune...until then, enjoy ~20 psi without the taper, which is about all you can do before a tune.

EDIT: I just noticed you have been flashed...was your fuel cut threshold raised?

 

Unless you bought the iridium plugs that come pre gapped you should have gapped them to .027. Are you tuned at all? Its hot outside so if you are hitting fuel cut at 21psi then you are probably running really lean.

 

even with a walbro?

 

I had the same exact problem boosting to 22-23 psi.. had a P2R flash with boost cut raised and still had some issues.. I have the B7ES gapped to .026 and replaced them at 6K miles.. it worked wonders.. my .02c

 

Hmm I have to re gap my plugs today. Im going to gap the 8's to .28

 

I have just about the same mods as you except for the FMIC. I have tried the 8's but 7's run alot better in my car. BPR7ES gapped to .026 I change them every other oil change at 6k. They work very well.

 

If you're hitting fuel cut, it has nothing to do with the plugs. If you're sputtering right at peak boost, then it's the plugs or something in the ignition system. FYI, fuel cut will happen well after peak boost higher in RPMs usually, because there is much more airflow and fuel cut is based off airflow. You see more airflow with 18psi at 6000rpm than 22psi at 4000rpm. If it's happening right as you hit full boost, then it's probably not fuel cut and is probably spark-related...

FYI, you should not have fuel cut with a Dynoflash, but you don't have your flasher listed, so I don't know who dod it...

 

I already ordered some 7's instead of teh ones Im running now...

Hey Warr when will Al be doing Eflash's again?