Problems with my 305 TBI to 350 speed denisty TPI swap in my 91 bird.

how can i tell if i have a bad ECM?
i hooked up a SnapOn scanner to the ALDL and it's telling me i have no commincation with the ECM.
i put in all of the info that the scanner needs.it then promps me to turn the key into the run postion.once i do that the scanner screen goes blank for a second then pops back up and says there is no commincation with the ECM.
i checked the grounds going to the ECM and i have good grounds on those pins.i checked to see if i have power going to the ECM.i have over 12 volts going to both of the pins at the ECM.
i tried to pull codes by jumpering A&B at the ALDL.i couldn't do it that way either untill i jumpered A(ground)to a ground.then i could pull codes.i got a code 33 which is a MAP code.i then hooked the scanner back up and it does the same thing but the scanner screen doesn't go blank like before.
the car starts and runs(some times)really rough.

 

if you can get it to flash12 by jumping the aldl the ecm is working. does the car run right? have you checked for power to the ecm?

 

yes it does flash a 12 three times.i tried switching the pins at the ALDL(from E to M)and still can not access the ECM with the scanner.
the car fires right up flash's up to 1k rpm's then quikly drops to 500 rpm's.it ruuning very rough but it idles(kindof).i have fuel pressure gauge hooked up to the fuel rail and the gauge says 15psi regaurdless of how many turns i put on the AFPR.when i open up the butterflies it acts like it getting way too much air.the idle drops and tries to stall out.i have a 255 Walpro pump,it's the second one that i've had it the car.the first pump i was only getting 0.05 omhs across the pump(bad pump).
i have over 12 volts going to the the two battery power pins.and i check the grounds going to the ECM there good.

 

well i'm pretty much a dumbass, but i was thinking if you get a 12 it'sa self test indicator to let you know it works. maybe it doesn't have any codes stored. have you tried to access the data stream?

 

the only code that i had was a code 33 (MAP)my manuel say a poor idle could be throwing the code.which makes sence since it idleing pretty ****in rough.

how do you access the data stream?

 

TTT

 

data stream should be an option on your scanner. mine has "stored codes" or "data stream" on the menu.

 

well i'm thinking the ECM bad isn't now.
well long story short the car was running last,running alot better than it has been.and the ECM threw a code.so i'm guessing that my prblem with not being able to access the ECM with a scanner is some how in the wiring.

 

well i drove my car around the block last night
my problem was the MAP sensor wasn't getting enough vacume.i put a 91 plenum on and a new MAP.the 90-92 plenums have a third "nipple" for the MAP vacume source.besides a real bad header leak she felt real strong