Cadillac Repair: mpfi 4.5L miss fire, deg btdc, vacuum leak

Question
I have a 1990 cadillic Diville Sedan 4.5L mpfi v-8. i just overhauled the engine due to a vacume leak between the head and the intake manifold, and poor oil circulation to cylinder 2&4. approx. 500 miles after the engine was installed i devloped a miss. i have spark at every cylinder and fuel at every injector. my fuel pump is pushing 40 psi at the rail and holding the psi. i have replaced the carbon canister, iac motor, map sensor, throttle body, rubber and plastic vacume lines. the vacume release for the parking break doesn't work. i am unsure if that is a contributing factor. the heads were machined and rebuilt with all new parts, and the intake was machined at a respected machine shope. the timing is 14 deg. btdc every time i get it to 10 deg. the computer adj. back to 14 deg. please help

Answer
If you have a vacuum leak and there is no vacuum getting to the ON/OFF switch located on the steering column for the E-brake release this will definately give you a miss.

I can also provide you with a test procedure to test each fuel injector and set the ignition timing correctly.

E-mail me at: onlineautohelp@msn.com