blysccr

86 951 with cone filter conversion 3 inch lindsey exhaust and chips. when i got the car it ran great. then 3 or so months ago it started backfiring and the air/fuel gauge showed running rich as soon as the car hit boost. then i cleaned out the filter and it ran better, backfired much less. then recently, whenever i hit boost the car runs ****ty. not like it should. my boost gauge only reads 11, whereas it used to be right on 15. what the hell is doing this!!!!!!!!!!!!!!!!!!!!

billthe3

Check for vacuum leaks?

xsboost90

hows the flapper door doing? If your filter is not doing a very good job, youll get junk in the air meter and the flapper will have problems moving and it will not work right. PUll the filter and see if it operates smoothly, or if it sticks.

blysccr

theflapper works right.

sweet9fortyfour

Is it back firing when you let off a exhaust leak could cause the low boost and back fire.

blysccr

sometimes, and downshifts. there is an exhaust leak, but it's behind the turbo, i don't think that would have anything to do with pressure?? i can't see how a leak behind the turbo would do anything since it's just exhaust, but i'm going to take care of that soon
thanks

blysccr

vacuum leaks....what's the best way to approach that?

FRporscheman

With the engine running, start spraying carb cleaner (or brake cleaner) on all the vacuum lines. As soon as you hear the revs go up, that means you have sprayed onto a vacuum leak. Some people say a propane torch works as well, but I'd stick with the spray.

blysccr

thanks, i'll get on that tonight. what if it's at a fitting?