91 f-150 with 302, it had a tune up in april of this year.
now it bucks and almost die out and the check engine light come onand stay on. the fuel fliter has been changed.but it will not act up untill it reach normal runing temp, Then it act up?
you stop and turn the engine off and try to start it it and s
die two or thee time then run rough and the check engine come on.

 

When the tune up was done, did you do wires? That particular engine and year combo had a problem with ign. wires interfering with the primary signal. The plug wires need to be run 90 deg across any computer or primary wire harness. Otherwise it sends rf noise to the computer and makes it run BAD. I thought I had a plugged cat when it started doing it to me. Found a TSB that fixed it.

 

Harry, welcome to the board !!!!

I had a problem that sounds like yours. Mine would just lose power for about a minute or two and then all of a sudden just surge up again with power. It would do this in rotation about every two to five minutes. The engine light will come on as well and when it does, the computer sets a code. I can't remember the exact codes but when you get them read and it has to deal with a lean and rich condition. Put another Oxygen sensor in the truck. I didn't even have my new O2 sensor for 25,000 kms and it went bad on me. Let us know !!

Have Fun & Keep on Truckin'
Dean

 

as it turn out it was the throrttle postion sensor was bad and need replacing. The two wires to the sensor were rubing and wear the coating through and the two would touch and shorted out. the sensor.
harry