got a problem with backfiring with high boost and low rpm.
can anyone help?

 

sorry if this is a bit sarcastic but....




turn down the boost maybe?

lol

 

You mean on decel? Or does it always do that

 

Also, check your plugs. If they are stock (god, I hope not. They suck), or if you're running higher than stock boost on factory heat range plugs, they may be heat fatigued. I know this may sound strange, but;

1) people running higher boost run colder plugs. The higher the boost, the colder the plug. PSIchick, Mchat, Posthondaremoval, and some others know more about the specifics than I do.

2) I used to have an '87 Ram van w/ a 318 V8. The factory plugs were champions (lack of capitalization was not an accident). The Autolites that were the cross-reference were a colder plug, b/c they had a wider variety available heat range wise. Anyways, after 10k mi on the stock champions it started backfiring through the carb under load and soon became almost undriveable. A mechanic friend of mine told me to change the plugs. "Yeah, right", says I. "It has to be timing related to backfire through the carb". I checked timing, changed the fuel filter, air filter, cleaned the carb, etc. All to no avail. Finally I had nothing to loose, so as he advised, I swapped out the plugs for the Autolites. Worked like a charm. I ate crow for supper that night, but for the next 175k mi that van ran great.

You didn't say whether the backfire was through the carb or the exhaust, and I don't know if these two situations have anything to do with each-other, but I thought I'd throw this out there.

Good luck,

Scott

 

here's a better question...why are you at high boost in low rpms? try downshifting, it's much more effective.

is it a studder or a backfire that you're getting?