I have a 97 ford f150 4.6l got gas started driving and it started missing than check eng. light started flashing than stayed on it has never done that till today

Take vehicle to a local auto parts store and have the ODB codes read. Most big name stores do this free of charge.

Knowing the diagnostic codes will give you the information necessary to make an informed decision as to why the CEL is on. It could be something simple i.e. EVAP (gas cap is loose), or something that will require an experienced mechanic/tech. Since it was noticeably missing likely not the gas cap but you need to have codes read for you to make an informed decision.

Any check engine light?

If it is a serious miss, you should have a code in the computer telling you which cylinder.
If you have replaced the ignition parts and there are no vac leaks, the next phase would be fuel including the injector.

OK first thing is to go to c am Sensor on drive shaft could have lack of lubrication.
Also test the throttle position sensor and replace if faulty, as both of these can cause your problem.
Alsoinjection loss to 1 cylinder can also be......
check wiring to injector ,known to give a problem and if ok then check enginecontrol module as it may be falty.
So let me know how you get on .....................Ron

if you havn't replaced the fuel pump yet that should do the problem

you could have a bad tork converter clutch and you could have a bad injector. also the new wire or plug could be defective but is not likely. Did you gap the new plug?

P1143 Air assist control valve range/performance

Could Be your mass air flow sensor. Start there.

don't know the answer to this; but we have the same prob with our 97 contour; when starting out and driving at times to it "misses" alot and the check engine light has been on for over 2 years! lol

Make sure the gas cap is there and is fully tightened (it will click), a loss or missing cap will turn the check eng light on.

IT LOOKS LIKE YOUR FUEL PUMP IS GOING BAD