for the past few day i have noticed a slight hessitation around 45 usually when u jump on it at the speed it sets you in your seat....it acts if it is overloading or something...it has new plugs, cap, rotor and wires. i also run premium fuel and fuel injector cleaner regularly ....any ideas im stumped!:help2:

I don't remember if the 97 7.4's had a MAF sensor, if they do then maybe this....I see by your sig that you are using a K&N air filter. IF the filter as been over-oiled either from the factory or after maintanence the excess oil can be sucked into the MAF sensor area and the oil sticks to the thin sensor wire causing a faulty air reading. It can be cleaned by spraying it with an electronic cleaner (Tuner Degreaser) available at your local Radio Shack. It can also be cleaned with a Q-tip and 70% alcohol, but you must be careful to not break the wire.

Another possible problem may be your fuel filter being clogged. Most folks aren't even aware they have them, and I think they are located under the truck next to the frame on the passenger side. Or, possibly a failing fuel pump.

Just as an FYI and without starting a huge debate, your truck was designed to run on 87 octane. The 92/93 octane may actually hurt your performance after prolonged use. It can cause carbon build-up in combustion chambers, valves, and on the cylinders. I doubt this has anything to do with your stumbling though.
JP

Even though they are new check all the connections on your wires...make sure that they are completely on the plug and the cap...almost sounds like a slight misfire....as mentioned above also check your mafs...grab some electrical cleaner and spray it down...can't hurt.

thanks fellas ...i just put in a new mass air flow sensor and also a fuel pump/ sending unit...so i am still kind of at a loss here...in remark to the 87 octane....when i run it i would be lucky if i could jump a 21 speed huffy bicycle in a race ...but thanks for the input

I know you'd hate it, but maybe it's time for the dealer to do a little diagnostics and maybe point you in the right direction. I mean if you have a stumble and you have replaced plugs, cap, rotor, wires, fuel pump, and MAF sensor it's gotta be something wierd. Only other things I can possibly think of is anything to do with timing...like maybe a tooth off on your timing chain or maybe a burnt valve hangin' up or sticking.

Oh, so what about the fuel filter? Doesn't the '97 have a canister type (about the size of the small tomato paste can) filter located under the truck on the passenger side...next to the frame? I didn't see a response on that item.
JP

yes you are right but its against the frame rail on the driver side just behind passenger rear door...yeah that thought had crossed my mind about the dealership but my cousin owns a garage and we threw it on the snap-on diagnostic machine and it the up the O2 sensors so i dunno that maybe the next step...