my engines rans bad after washing it

[Mr 5 0]

The TFI and the coil are clear suspects and need to be checked. If you have a buddy with a similar 'Stang you can check the coil by switching it with him for a test drive.
A used (junkyard) coil would also work for minor expense. If the problem is solved, buy a new coil.

TFI modules usually just crap out entirely and disable the engine but dampness could be a factor, too. Engine heat should have dried it out quickly but corrosion is a factor in anything electronic. Once a contact is compromised by corrosion the part usually malfunctions.

It's also possible you got some moisture into the Mass Air meter, especially if you didn't protect it, as it sits right on top, easily sprayed. Common mistake when washing an engine.

Try disassembling the meter (2 screws) and check for moisture inside, using a Q-tip to dry it, if necessary. Be very careful about touching the hot-wire with anything other than a Q-tip.

One of these parts is probably the culprit. I vote for the Mass Air meter - but no bets.
It could also be a shorted wire lurking somewhere or some other electronic part was dampened. Check all the spark plugs and plug wires for cracks. Replace what's needed.

Good luck and let us know if and when you find the problem - or if it just 'goes away' as the part in question dries out from engine heat.