I have an 1989 XJ when I drive it it runs fine has plenty of power. When it heats up I loose that power and have nothing still runs and idles fine but if you put your foot down on the accelerator it just sputters and backfires. Any help would be greatly appreciated. I have put in a new fuel filter, plugs, air filter, plug wire, distributor, and MAP sensor. Thanks cool website to.

89XJ3"

 

this sounds like a cat problem,it could be plugged up.

 

The Cats been cleaned and cut out.

 

First you need to replace the cat,it is illegal to run without it,it sounds like you have an obstruction.

 

WOuld it be worth it to get a new cat. Even if the one i have is cleaned out?

 

You need to replace it and then go from there,a cleaned out cat is not a cat anymore,it is just a pretty pipe.

 

89XJ3",

Sounds to me like you have an O2 Sensor or possibly a Temp. Sensor problem...I'm talking the air inlet temp. sensor that feeds info. to the ECU, not the one that tells you how hot the motor is. Both of these sensors send info. to the ECU and in return the ECU will lean out the fuel mixture when your motor gets up to normal operating temperature. The mixture, as we all know, is richened when the motor is operated cold. Sounds like your ECU is not being told to lean the mixture out so when your motor gets warmed up it's getting choked out with too much fuel. i hope this helps you out.

 

Is there a quick way to check those?