Ok so i took my ECU and prom out to see if i had an after market PROM becuase this car is supposed to have an over bore and if it was a factory PROM it shouldnt be running rich but instead running lean. So i removed the prom and took it inside to my dad so he could used his GM program to find its part number to see if it was stock. well..... needless to say he couldnt find it. i even searched through ALLDATA and couldnt find the part number. i looked through all 305 TPI firebirds from 82-92 and could not find the code that was on my prom. so i though i would come to you guys and see if any of you have had the same prom. the ECU has evidence of being opened before. here are the numbers.

PROM:
DELCO APYR 3506
16069300

ECU (this is to the best of my ability to read it):

O.E. 1227165
CALIBRATION CODE 0494
ECU NUMBER 7-7165

now im used to seeing the ECU's that are silver and have to PROM door at the end of the ECU. but mine was black and had the door in the middle. so i dont know if this is normal or if this is some different ECU.

my vehicle info:

89 formula firebird
305 TPI MAF
VIN "F"

if you need anymore info just ask i will answer to the best of my knowledge.

 

its a factory PROM & shows to be an update for ANYC

 

yeah we know it is a factory prom. but i have looked through a list off all the factory prom part numbers and that number did not exist for the firebirds TPI or TBI from 82-92. and these were all the numbers for every one made for my car. thats why we are confused. my next step is to look at all the prom codes for the camaros 82-92 but im sure they will be the same. the number didnt even show in the updated prom list.

 

Google is your friend.. =)

http://chevythunder.com/prom_bcc_1989.htm

 

dang what did you google search. i typed the number in and didnt get anything. whats bad is that GM didnt even have it listed. thanks for the help guys.

 

I googled APYR 3506

 

duh!!!! didnt think about that. i do have another question though. is it possable that a prom was not connected all the way and still let the car run with not problems? the reason i ask is that after i reinserted the prom and took it for drive the drove differently that usual. it felt like she had a little mu punch to her for some reason. idk i could just be imagining things i guess.