it seems like my truck dosent really want to go over 65-70 , it will speed right up to those speeds but once it gets there is accelerates REALLY slow and really doesnt want to go faster but it will eventully speed up. o yea its 89 5.0 AOD , ideas are apriciated

 

Hows your basic maintenance?
Plugs, fuel filter, air filter etc.
Might be time for a good tune up day.

 

the only things that hasnt been done is the fuel filter , and it is due for an oil change , and maybe the trany filter/fluid, but everything else has been done in the past few months , also its never really been a fast truck , hell i have trouble breaking the tires loose

o yea it has around150-160 thousand not 100% the speed sensor went out for a month or so before i replased it

 

Go ahead and do the fuel filter, it sure won't hurt. Check for codes also. Here's the link in case you don't know: https://www.f150forum.com/f10/how-retrieve-trouble-codes-obdi-10907/

 

Not to hijack the thread but I did not realize you may have a code without having the check engine light???

 

just wondering , were is the fuel filter? and would a tranny filter help could that be holding back power? and yea i was thinking about running codes , would any of you recommend just using one of the code readers that plug into the connections?

 

Yes, there can be codes even though the light is off.

You don't need the code reader, doing it the way posted works the same and gives the same codes. You won't have to chase down a code reader either or waste money buying one. The fuel filter is on the frame rail ahead of the switching valve. Changing the tranny fluid and filter will help the truck generally but it probably isn't holding back any power.

 

i'll probably do codes sometime this week , and possibly the fuel filter too

 

Keep in mind that the 5.0L for that year was rated for only 185hp. What axle ratio do you have - IIRC, the only options were the 3.08 and the 3.55. Also keep in mind that you're trying to push the aerodynamic equivalent of a brick wall on down the road. The speedometer only going to 85 doesn't help :-)~ This being said - really important to make sure everything is working as best it can.

I have the same setup - 5.0L, AOD, and have the 3.55 axle. See the same thing you do - around 65, just seems to lose its oomph. Keeping it out of O/D helps somewhat - but concerned about flogging the tired horses any more than I have to.

 

I have a 1991 5.0L AOD, 3.55 gears long bed single cab sure the trans has been rebuilt last year but the engine has not and I can do 85+ even when it wasn't rebuilt. GPS certified 100mph. Saw a cop shortly after, but it was still pulling. nothing in the back, one other passenger. And the fuel filter will help out with that sluggishness a bit, trust me Plus another thing you can do is disable that EGR valve. Puts exhaust gases back in the intake, kills power. Then plug it back up for emissions. Not like were driving a prius anyways!