Back fires, popping and loss of power

Discussion pertaining to positive pressure E28s.
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5timesturbo
Posts: 315
Joined: May 26, 2013 3:24 AM
Location: Fayetteville, Ga

Back fires, popping and loss of power

Post by 5timesturbo »

So, I'm running stock engine management except for a TCD chip, BEGI rrfpr and of course bigger injectors (30# if it matters). I've got a MSD 6a as well. I most recently got my boost situated …..I'm trying to keep it around 13 to 14 lbs at the moment. SOMETIMES when I get to around 14lbs and I'm high in revs the car pops, I think it backfires....I know for sure it kinda boggs down and loses power. I try to see what the air fuel meter is saying when it does that but its so much going on in the car....I'm not sure if I caught a glimpse at the right time. I believe its saying somewhere in the 10.5 range. I think my rrfp is raising to fuel pressure too high which is making my mixture exceedingly rich....but I ask you turbo m30 pros....what you think it is....or how I can go about remedying this issue. I want to be able to smoothly go through the rpm no matter how hard I'm driving the car…… Is this a rich/lean situation or does it sound like something else???
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: Back fires, popping and loss of power

Post by marc79euro645 »

I'm not sure whats going on, but, I can tell you when jetting motorcycles, popping under acceleration = too rich. Popping on decel= too lean. It could also be spark blow out. I'm using an 6a with blaster2 coil. It helps to know spark is not the problem. Also try spark plug gap @ .028" good luck!
5timesturbo
Posts: 315
Joined: May 26, 2013 3:24 AM
Location: Fayetteville, Ga

Re: Back fires, popping and loss of power

Post by 5timesturbo »

marc79euro645 wrote:I'm not sure whats going on, but, I can tell you when jetting motorcycles, popping under acceleration = too rich. Popping on decel= too lean. It could also be spark blow out. I'm using an 6a with blaster2 coil. It helps to know spark is not the problem. Also try spark plug gap @ .028" good luck!
Thank you for the response. I was told I'm a bit too rich because my wide band is reading 10.5 in that situation and should be between 11.5-12.5 for the setup I'm running. At this point I'm trying to tune the BEGI rrfpr and the airflow sensor to get the desired A/F ratio throughtout the my rev. I AM running the 6A msd and blaster coil and I did gap the plugs to 28. ...they might be old...I have been running rich for the 5 months I've had this system in the car..... I will keep everyone updated. I'm guessing this is why ppl go stand alone.....
5timesturbo
Posts: 315
Joined: May 26, 2013 3:24 AM
Location: Fayetteville, Ga

Re: Back fires, popping and loss of power

Post by 5timesturbo »

Well... I've been leaning out my mixture and its gotten better. Thanks for the help ya'll.
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