Slow XJ

[CHEOKEEJOHN]

Any ideas, on how to get a lil more HP outta stock 2.5L. I was headin into Reno last week on a decent grade. Pedal literally on the floor, doin' 60 and slowin'. Is this just to be expected as it gets older (100-110K)mi.
Thanks

 

[martin]

sounds like a bad cat converter, it partially plugged up. I'd have it replaced along with the muffler and tail pipe. If the cat chunked out then it also trashed the muffler.

Also make sure you have a clean air filter. Sound like a lack of air flow- either into or out of the engine.

It is also a general practice to change the oxygen sensor when chaning the cat, just in case your oxygen sensor is bad.

 

[Dr. Dyno]

You probably do have a plugged up cat so replace it with a Carsound high-flow unit. You can also replace the muffler with a Flowmaster 50 series 2.25" inlet/outlet unit. That'll help for starters.
The intake is not too bad. You can replace the old paper filter with a K&N drop-in element, and replace your TB with a TB from a 4.0. That'll really wake up your 4-banger.

 

[BrettM]

is this XJ relatively stock? if you have big tires that's just to be expected, especially if you don't have the right gearing. When I put my 35s on to go to the trail and head up into the Sierras, my 200k mile 4.0 doesn't like going over 60 on a lot of those hills, that's with 4.88 gears too.

 

[CHEOKEEJOHN]

...and replace your TB with a TB from a 4.0. That'll really wake up your 4-banger.

Forgive my ignorance, whats a TB? I can think of a few things it could mean.
Thanks

 

[egon]

TB == Throttle Body

--Matt