Running lean in Boost, Help
Melting Slicks
Joined: Mar 2006
Posts: 2,754
Likes: 380
From: South Florida FL
so a boost leak at the intake made it run lean? that's not working out in my head, if the air is already metered at the maf, and leaking boost at the manifold, the AFR would be rich, as it's providing fueling for the air that's already metered at the maf, I'm assuming the car isn't on speed density, since it only has a 1 bar map sensor. someone tell me if I'm wrong, I'm not familiar with boosted MAF cars.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
You must not of read what I already stated , The AFR its richer from 13.2 to 11.9, Yes Read next time. Car has already been tuned by a competant person, it runs great
Last edited by corvet786c; Sep 20, 2021 at 06:54 PM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
so a boost leak at the intake made it run lean? that's not working out in my head, if the air is already metered at the maf, and leaking boost at the manifold, the AFR would be rich, as it's providing fueling for the air that's already metered at the maf, I'm assuming the car isn't on speed density, since it only has a 1 bar map sensor. someone tell me if I'm wrong, I'm not familiar with boosted MAF cars.
Melting Slicks
Joined: Mar 2006
Posts: 2,754
Likes: 380
From: South Florida FL
ok, gasket manifold leak, boost leak, same thing. I was just trying to understand why. technically with it changes, should be getting more air into the motor, making it leaner, I'm wondering what other tables you have that's adjusting fueling. The oil getting into the intake manifold, is from your PCV/breather system. it'll eventually be oily in there again, you just wont see it from the outside now if the original gasket was that bad.
also, I assume you datalogging, whats the max KPA are you seeing from the MAP sensor? and how much boost are you running
also, I assume you datalogging, whats the max KPA are you seeing from the MAP sensor? and how much boost are you running
Last edited by FourG63 97GST; Sep 21, 2021 at 11:11 AM.
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
ok, gasket manifold leak, boost leak, same thing. I was just trying to understand why. technically with it changes, should be getting more air into the motor, making it leaner, I'm wondering what other tables you have that's adjusting fueling. The oil getting into the intake manifold, is from your PCV/breather system. it'll eventually be oily in there again, you just wont see it from the outside now if the original gasket was that bad.
also, I assume you datalogging, whats the max KPA are you seeing from the MAP sensor? and how much boost are you running
also, I assume you datalogging, whats the max KPA are you seeing from the MAP sensor? and how much boost are you running
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
ok, gasket manifold leak, boost leak, same thing. I was just trying to understand why. technically with it changes, should be getting more air into the motor, making it leaner, I'm wondering what other tables you have that's adjusting fueling. The oil getting into the intake manifold, is from your PCV/breather system. it'll eventually be oily in there again, you just wont see it from the outside now if the original gasket was that bad.
also, I assume you datalogging, whats the max KPA are you seeing from the MAP sensor? and how much boost are you running
also, I assume you datalogging, whats the max KPA are you seeing from the MAP sensor? and how much boost are you running
https://forum.hptuners.com/showthrea...ns-Logs-Thanks
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Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
Pro
Joined: Apr 2006
Posts: 534
Likes: 82
From: Charlotte NC
Since I am using a stock1 bar there is a strap inside that stretches and measures pressure each and everytime past 14.6 psi, To my understanding, well keeping this up, once that strap stretches to much it breaks and the Map is no good. Yes Ideally I should of been tuned for a 2 bar, but wasnt. This morning I put the old MAF on and forget it, car was stumpling.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
Well for the record after all this time, I finally figured out what was wrong, Not the Wideband or AEM Guage. The updated Delphi MAF was the problem, Mine was tuned with old part number 25168491. So I bought one on ebay all, I had to do was unhook the battery for 30 min for the computer to relearn MAF. Looking at the data log graphs, O2's are were they should be and AFR reading 10.5 to 11.7 under boost. Now I am battling knock.
Race Director
Joined: Dec 1999
Posts: 10,230
Likes: 885
From: Alexandria, Virginia, USA VA
look at pulling timing and doing a "hook test" You slowly advance timing until the engine doesn't make more power but also stays far away from detonation
save that piston!!! No build will survive the pounding from detonation.
save that piston!!! No build will survive the pounding from detonation.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
Yeah, I am getting retuned and going speed density, should take care of my problems.