Re: Sluggish 88 F150
if it is an injector you will have a cylinder out,, check vacum, needle should be still/steady on 15 to 20 inchs vac. at idle , you could just listen close to tail pipe,, you will hear if one out. So does it have an air flow meter, or is it map sensor. Best ya check ya basics, change tune items,, if still no luck take to ya nearest dealer to sort out, ANd tell them ya changed spark plugs etc,, but still no fix. I would make sure runnig on all 8. then look at fuel, fuel pressure, it should be runnig about 35psi at idle then when snap throttle should come up a bit to about 40-45psi. and timing, check at idle,,with timing light. check full advance at about 3000rpm,, should peak then 38deg around about., does it still have distributor.. or all timing done by computer?. another thing, Does it have single coils for each cylinder or running four coils. one for two cylinders? I know that if one of these coils fail,, then you loose two cylinders.. let me know how ya get on.