Got an '89 F150 and recently the check engine light came on and when I start it up in the morning in doesn't warm up like it used to..........used to rev high at like 1500rpm for 3min.'s then idle down 800rpm when warmed up..........now just revs up and down and will stall if I dont hold the gas down, and when I drive it whenever I let go of the gas it kind of "sucks in" and slows down like Im hitting the brakes..........does it sound like anything obvious like a idle control motor or something? Thanks to all........

 

Is it EFI ? What are the codes?

 

had a similar problem depending on your code(s) mabye coolant temp sensor or low coolant

 

it could be a number of things. first i would check the mass air flow sensor, the EGR valve and the Idle control sensor. would help out a lot if you were able to let us know what the code was.