Lean after few seconds
I'm having an awful time with a lean issue, I'll try to add all the things I've done cause I need serious help! Setup is 347 with turbonetics 67 mm turbo, blow through carb, boost ref reg, boost reference msd, makes 12 psi, a1000 pump, all an lines w/return, timing is 28 deg total, plug gap is .022, I'm sure it's not all listed but feel free to ask.
So, I can take the car out and drive it and it's decent, was in the middle of tuning. Wideband is 12.5 at cruise and 13.3 under boost, it was hitting good 2-3 gears. Came back and made jet change, that's how I made the 13.3. Then I went down and now I mat it and it holds 13.3 for about 2-3 seconds and then it spikes the wideband and lean pops. Since this I added the a1000 pump, it's making fuel psi so I'm now stuck, I don't even know where to go from here...
1985 Mercury Capri