I have a 1999 Jeep cherokee sport with 150K miles on it, truck runs great - but the acceleration sucks, especially on the highways - if i wanted to pass someone. Anyone know what i need to do, replace, put in, clean in order to get some of this back?

thanks.

Well, if you have the 4cyl, there's not much help. :icon16:

But if you've got the six, (and actually for any engine) there are things you can do.

1) Fuel injector cleaner.
2) Tune up (plugs, and if you have them, cap and rotor)
3) Replace fluids, if you haven't already, including transmission and differentials.
4) Try this product: www.auto-rx.com I have used it, it works, smoothed out my engine (with only 90k) and gave more power.
5) Air filter

That's a general start for the maintenance to do if you want to leave it stock.

You sure it runs great? 4.0L?

Start with a tune up.

Compression check?

I have a 1999 Jeep cherokee sport with 150K miles on it, truck runs great - but the acceleration sucks, especially on the highways - if i wanted to pass someone. Anyone know what i need to do, replace, put in, clean in order to get some of this back?

thanks.

First off, we *are* dealing with an inline six....and while the 4.0L is adequate in the XJ, in stock form it's no scorcher. That being said....

I agree with having the engine compression checked and/or using an acient device called a vacuum gage.

I agree with the tuneup....

I agree with cleaning the injectors...but not with one of those "pour-in-the-tank" wonder cures. Invest in a professional upper intake and injector cleaning...this can be done at most reputable shops and should run around $75-100. It makes a big difference.


mike
00XJ

whew! Now that he AGREES we can all get some rest.

Do you have oversize tires (larger diameter than stock) installed? Everything else being the same in the drivetrain, bigger diamter tires are akin to a taller (higher numerical) final drive......

mike
00XJ

whew! Now that he AGREES we can all get some rest.

Dere's always gotta be at least one wize guy.....