hi all !
im new to jeep ownership and also to the forum so im hoping there is some jeep knowhow on here to help me ?

ive got a R reg 2.5i sport and the other day i thought i would replace the plugs and clean the earth terminal as it seems to struggle starting "like the battery is dead" but then starts and after i did so it wouldnt run properly ?
once it starts it seems to run fine ....but it wont rev properly ...not past 3-4k and when driving wont go much more than 10mph ....there seems to be no problem with spark or fuel but there is no engine check light ?

im now compleatly confused and cant seem to find any answers to my problems ...im also waiting for a friend to come and plug in his diagnostic box to see if that shows anything ....!!!!

so frustraited ...just want to enjoy my jeep .
anyone had or heard of such a probnlem.....

any help would be greatly welcomed

R Reg would be a 1997 for our US cousins

Could you check the build date to confirm?

hi sorry ...its a 98 ,
ive just had my mate round but cant find anything on his fault box ...it didnt have a jeep setting but still didnt show any codes on the generic setting .

he said i may be due to a bad earth ...or maybe the cat ?

All XJs have On-board diagnostic that are accessible by quickly turning the key from off to ignition-on 4 times in succession. If there is an engine management fault, It'll give you a fault code on your milometer that you can then google.


Check all your vacuum lines off the inlet and particular the one to the MAP sensor (flatish black square plastic thing with one small pipe in and electrical plug) (not sure where it is on yours - early ones are mounted to the bulkhead, later ones are bolted to the throttle body).


Hope that helps.