Have big problems whit a 2007 mustang GT.
It has a 5.3l stroker engine 11:1 compression
Ford racing "hot rod" cams
Longtube headers.
Ford racing intake and throttle body.
A shop have built the engine and made a "start up tune" whit SCT for it.
And tolde the guy to drive it for a while and then finish the tune. But its almost not driveabel.
Its is runing pretty ok on very light loads but as son it gets some higher loads its start leaning out and missfire.
They dont whant to deal whit it. So he asked me if i could have a look at it.
No fault codes.
Have tryed to adjust the maf curve it dont reakt to it.
I would put your Open Loop TPS threshold table back to 50% or 56.6%, so that your narrow bands are active in more of the MAF failed table. You can populate the load and get fuel dialed in with those for the part throttle stuff. You will also be able to diagnose air leaks much easier with out it going into Open Loop unnecessarily, so quickly.
After you raise that up, add 10% to your entire MAF curve and entire Load with failed MAF table. Log it, stay below 60% throttle, and see if your part throttle short term fuel trims respond to those change. If they do, you should be able to populate that part of the MAF and load table. If they don't, you will need to diagnose where its leaking air (intake or exhaust), or misfiring.
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