Removed complete dash Ac and Heater in 90 gt 5.0 now not running right

cali55 said:

I completely removed the whole dash because im building a custom aluminum dash. In doing so i noticed there is a black vacuum line that goes to the ac heater selector. If the knob is in the off position you would think that its the same as being capped off. Well i removed everything down to the black line itself and now my mustang runs really rough,backfires like crazy, has no power at all and check engine light keeps coming on . I tried completely capping it off,pinching the line to allow minimal air flow, took the rubber nipple off at the vacuum tree. And the same result anyone have any suggestions

Click to expand...