Ive got an 87 gt 5.0, with a 5 speed trans. Its engine swapped with a cobra engine from a 93. Its got serious issues, I just recently bought the car after it had been sitting in a field for 5 years. It has a serious misfire but I don't know what cylinder. Ive tried getting codes off of it but the hookup for the scanner doesn't get power so i'll get codes once the connection has power once I figure out why it doesn't. The whole car is in rough shape and im trying to Bring it back to life but its in seriously rough shape. From what I know it has a very serious misfire, doesn't idle (stalls as soon as it starts and you have to keep it alive by giving it gas constantly, once its warmed up it idles on it own for a short period of time. when given gas to keep alive it jumps up to 2.5k rpm then drops to about 500 and wants to stall.) it also runs extremely rich and fouls plugs like you wouldn't believe. I don't know what the timing is set at. anything helps thanks.

 

I'd just check for loose connections, broken vacuum lines, clean your maf. New plugs wires and check the timing to start (after new fluids etc). Did the previous owner swap everything over from the cobra? They have a different computer, throttle body, injectors, maf if everything wasn't swapped it could create issues as well.

 

im not sure if the computer is original to the car or was swapped with the cobra, ill definitely have to check all of the above. is there anyway to tell for the ecu if its from the 93 or the 87?

 

I'm not a fox expert so someone may correct me, but the 87's were A9L computers and the Cobras were X3Z computers. I'm pretty sure it say which kind it is on the sticker on the side of the ecu

 

okay, ill check when I get home and update on what computer is in the car

 

87 won't have a mass air meter if the computer is original

 

I thought they switched them in 87 to mass airflow?

 

Mass Air started in 89 5.0.

 

87 was speed density. cobra engine with a stock speed density set-up, could maybe cause some problems. the computer didn't get a signal from a speed sensor then either i think. that could cause some problems too i imagine with the swap

 

It would run horribly without a maf signal, my new one wasn't reading at all due to a faulty adaptor and it was horrendous to drive