97 F150 Hesitation

[Musky_Madness]

I have a 97 F150 with the 4.6L V8 that is having continuing problems with hesitation. I had some problems back in January and had the truck into the dealer who replaced a COP and the plug in cylinder one. Several weeks later the truck began to hesitate slightly again and I figured I better replace the remaining 7 plugs. So I replaced all 8 with Autolite Double Platinum plugs in February and all was well. This past week, the truck began to hesitate and buck again and I replaced all the COP's now on my own. The truck ran fine for the rest of the day and then it started happening again. I am now at my wits end! I have ran seafoam, new gas, injector cleaner through it with no results. Any ideas of what could be next? I did some googling and found a possible EGR problem? Is this something easy to tackle on your own? Thanks!

[Jeremy airjer W]

Maybe a little more detail on what exactly the vehicle is doing. Is it running ruff or is there a lack of power on initial acceleration only, or is it running ruff only while accelerating?

Check engine light?

[Musky_Madness]

Hey airjer, here is some more info. There is no CEL on at all. There hasn't been one since this began. When the vehicle is in park it runs fine. When you put it into gear and begin to accelerate it begins to run rough almost like its choking out. You can also smell a strong gas/oil smell when you are sitting at the stop light and it'll run rough as well there. There is a lack of power and when you accelerate hard it is very sluggish to respond. (125,000 miles on it)

[Scott K]

Is this a 5.4 and not a 4.6? I don't believe the 4.6 had COPs in 97.

[IFallsRon]

Check your throttle body gasket.

[Musky_Madness]

Would cleaning the throttle body also help? It is a 4.6L and has rubber boots going to the spark plugs. Maybe they are just the regular spark plug wires. I grabbed a new set from the man's mall. The wires run to a hub on either side of the truck and are numbered for firing sequence and did them one at a time so they would not be any different.

[98prosport]

So, when is the last time you replaced the fuel filter? These are often overlooked. I have changed some that I could not blow air thru!!! How did it ever run with that!!! Just a thought.

[Musky_Madness]

I have owned the pickup since June of 2007 and I have never replaced it. I'm guessing by the looks of the spark plugs I replaced a few weeks ago, the fuel filter hasn't been touched in a while.

[Musky_Madness]

Because I live in the Red River valley and I teach at the high school which is closed for the week, I have a tune up day scheduled for Monday. I am going to start by cleaning the Mass Air Flow sensor, cleaning the throttle body and replacing the gasket, replacing the fuel filter, and if I am feeling good at that point, I would also like to change the rear differential out as well. I spent all of last week sandbagging and stacking along the river with my HS students and have neglected my truck. Time to catch up tomorrow! Hopefully a day of TLC for my truck will reap a smooth and strong running engine once again!

[Shack]

Quote:

Would cleaning the throttle body also help?

Technically, the rule of thumb with Ford’s throttle bodies is you are not supposed to clean them. They have a special coating applied the inside horn that will come off if cleaned.

I think with the above said, you should be able to correct the issue. Let us know what the out come is.

Good luck!

[Musky_Madness]

Well I cleaned the MAF sensor with the electric circuit cleaner stuff and changed the fuel filter and it seems to be better so far. Taking off the fuel filter was a bear to say the least! The end towards the engine was rusted on there pretty good so I think that was a good indication of the last time it had been looked at. I will continue to run some errands today to see how it runs.