The engine has a little over 100K miles on it and most parts are original except what I just recently replaced.ĭoes this sound like a bad MAF, or a clogged cat or weak valve springs? I was planning on doing the valve springs next week, but I wonder if I have something else to check out as well. I was planning on unplugging it and see if I can push it harder. MAF counts are 7 at idle with the engine running. Normal driving around its fine and has plenty of power under 15psi, it's when I push it that it loads up and won't accelerate past 4K. I changed the plugs, wires, module, and a new delco coil so I covered all the ignition stuff, I also replaced the fuel pressure regulator and the ECM since my scanmaster wasn't communicating.

No timing retard on the scanmaster and no popping or any abnormal noises, just gets to 15psi and don't do anything. Now it will build almost 15psi of boost but The engine goes flat at 4K rpm. Well a new fuel filter solved that issue. So recently I picked up a 87 GN and I had a issue where it would bog out above 5psi of boost.

1987 buick grand national gas tank