07-09 M8 Tuning problems with elevation changes

I have a 07 M8 with a 09 ecm, older ADA boondocker box with the external EBC, kit is a OVS based race gas running a water to air intercooler. Trouble i'm having is my tune changes with elevation even with the EBC set to auto for elevation correction at 1:1. I can tune the sled in 5500-6500 elevation area and it stays pretty consistent until around 9000-10,000ft then it goes lean under boost. I tune it for above 9-10k ft and it's pig rich below 9k ft. When I ride in a area were I easily change between that elevation range it's a real pain in the ***. I tried my original 07 ecm that was flash to the 08 update with the same results. I notice on my stats screen the pulse width is way lower in the upper elevation and I have to really fatten the PSI maps up to keep it from going lean above 9k ft. Anyone else have this trouble with this? I know this setup is old and most guys that had it probably forgot some of the problems.

Yeah this ones got me scratching my head thought maybe it was the baro sensor on the Ecm, tried another with the same result I really doubt I have two ecms with bad baro sensors. I was told to check fuel system for cavitation, I'm running a secondary pump were the stock one feeds it with a check valve in case the secondary draws more than the primary can supply to it (ovs setup). My fuel pressure gauge is in site seems to hold over 60 psi on the pulls so I'm thinking it's good. Plugs are a couple hundred miles old putting new ones in anyways, have a spare booney box I'm going to try. Basically only thing that has not been changed on this turd is the chassis control unit (07 one) do have a cat dc converter I may put on instead, fun sled but it's been a :juggle: all season.

Well I had a good day with this sled today, the fuel pressure regulator I have is the holley supercharger regulator. My base pressure was 34 and by 8.5-9 psi of boost I had 60+psi fuel pressure, at 10+ psi boost I was creeping on 70psi of fuel pressure. I'm not for sure but I suspect it was just pulling the voltage down to far affecting the ecm, one of those big walbro's at 70 psi is pulling some good amps. I was able to get my fuel pressure to 35psi start and about 55psi by 10-11psi of boost, just not sure why it was worse around 9000+ ft but at those area's the hills are longer/ steeper maybe more time to pull the voltage down:face-icon-small-con.

After some minor tuning the sled seamed spot on all day, could have just been luck though to :face-icon-small-con

I did power up both the EBC and boony box made sure both read the same boost= pumped up the EBC pressure line, also pulled a vacuum on the baro port it seamed to work smoothly. Tossed on another boony box for the hell of it, checked fuel pumps for air ect.