no highway acceleration

[mattc113]

89, 2.9, a4ld, stock gears, 31"s. will accelerate fine around town, up to 45-50mph, but when i get on the highway, i can barely get it to go 65mph and it wont rev past 3k in overdrive. if i shift to drive, it will rev higher and i can go from 55 to 65 in around 10 seconds, put it in overdrive and set the cruise, but when i come to a hill, it wont maintain speed.

 

[mattc113]

forgot to add, its a 4x4, and the cat was clogged, so i changed that, ive cleaned the injectors, not sure if its related to spark/fuel or the trans.

this is my daily driver, so any help would be much appreciated.

 

[Vexy]

You sure it doesn't have to do with the larger tires, stock gearing, and 2.9?

 

[mattc113]

i wouldnt think 31's would make that much of a difference. and up to 55mph, i have no problem accelerating, in fact, its quicker than i expected now that the clogged converter has been replaced. as long as i stay off the highway speeds its fine around town. stock tire size is what, 28-29"? i guess i could throw on some smaller tires and see.

 

[Vexy]

i wouldnt think 31's would make that much of a difference. and up to 55mph, i have no problem accelerating, in fact, its quicker than i expected now that the clogged converter has been replaced. as long as i stay off the highway speeds its fine around town. stock tire size is what, 28-29"? i guess i could throw on some smaller tires and see.

Only reason I'm saying that is because my truck has 33's, stock gearing, and the 4.0, and its a DOG on the highway.

 

[mattc113]

that might explain the problem if it was just slow acceleration, but it will not go past 65.

when a vehicle has lower gears, you can still go 70mph, you'll just be at 4500-5000rpms, lol.

 

[Vexy]

that might explain the problem if it was just slow acceleration, but it will not go past 65.

when a vehicle has lower gears, you can still go 70mph, you'll just be at 4500-5000rpms, lol.

4500-5000 is a bit excessive. Unless you are referring to a dedicated mud truck with 5.38's.

 

[mattc113]

well, i know that in overdrive, going 65, if i floor it, it revs to 3000rpm, and wont go any further. i can shift to drive, and then it jumps to about 3700rpms, but it still just barely accelerates.