1997 Jeep TJ

Engine Performance problem
1997 Jeep TJ 4 cyl Four Wheel Drive Manual 165000 miles

i have a 97 jeep with the 4cly and when im on the freeway it is hard to get up to 70-75 and when ever I go up a smalll hill or go over an over pass I can not maintain speed, if im going 70 I will slow down to about 63-65 and if by chance I am doing 75 then I slow down to about 60. I had the cat checked and that was fine but they found a very small crack in the header. I have checked the plug gap, wires, and cap and rotor and air filter and replace them all. Where should I think about checking next? People thell me that its just because its a 4 cly jeep but other people that have 4cly jeeps say that they dont have this problem!
September 16, 2010.

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Imma CJ Guy....Member like you (who answers a lot),

Answering is just one of my hobbies, I am not paid like the certified guys here.

I just try to help and try to stay within my boundries.

My answer may not help much, but here it is anyway!

I do not know your Rig.

1) Have you located 2nd and Higher gears----Try shifting into them!

2) 165000 Miles may tell some of the story--things wear in your engine.

3) Tire Size---stock?.......Wide---Big doesn't help.

4) Have you got a repair manual?....Fuel Economy means Efficency!......They are discussed within.

5) Additives such as Oil stabilizer might "Slicken" the engine up

6) Weght----We will let you hash that out with him/her/other!........I have my Standards, and You have yours.

7) Timing????????? No mention!

8) Vacuum Lines / gaskets and related gizmos broke/worn/deteriorated causing vacuum leaks?

9) Injector Cleaner?

10) You may be able to find a "Performance Chip" for your rig---Maybe....Try 4WD Hardware and Others for this item....if your rig will accept one.......Remember Imma CJ Feller

Explore the CJ 5 and CJ 7 posts other stuff there might interest you!

Here's my 2, No "Sissy" Names for "Rugged"---"Manly" Vehicles:

"Mr. Jeep" 1977 CJ5 258 6 cyl w/ 390 4bbl Holley

"WILLY" 1946 Willys 4 cyl L-134

Let me know if this stuff helps

I'm here, anytime you want to talk "JEEP"

My Profile reveals stuff I will share if you are interested.

The Medic

Sep 17, 2010.