First off, if this has been posted already I apologize. I looked for an hour without finding the answer.

I just got a '94 mustang with the 3.8 and am going to do a compression check once the car is delivered. I know how to perform the check but do not know how much pressure is supposed to be in each cylinder. I am also looking at a 3.8 out of a t-bird SC. If the pressure is different in this engine than in the mustang 3.8 what pressure should this be.

Thanks in advance.

 

Compare the highest reading from each cylinder to the others. The indicated pressures are within spec as long as the lowest reading is within 75% of the highest reading. For example if the highest is 150 psi, then 75% below would mean a minimum 113 psi. That make any sense to ya?