i recently purchased a 1985 t/a. the previous owner says he had the 305 changed with a 350, but it runs like crap. the car is equipped with a mass air flow sensor/ not a co sensor. can anyone tell me if any computer mods should have been done for this swap , or injection changes ? any assistance with this would be greatly apriciated, thank you.

 

Welcome aboard thirdgen.org.

I'd say the chances of it having a 350 are less than 75%. But, perhaps it is a 350.

The mass air flow system was more tolerant of engine displacement changes than the later MAP (or speed density) system. You should go through the basics first - condition of the ignition system, timing set properly, fuel pressure proper, fuel filter replaced, etc. While there may be something wrong with the injection system, it probably isn't that it's now trying to feed a 350.

 

thanks for the input, i'll start normal troubleshooting now. i'm just not up on computer cars.