I am looking at a 89 4.0, AW4, 231, D30, D35 240k miles,with 3 inch lift that is for sale near me. The owner is selling it cheap and I mean "dirt cheap". So cheap I can't pass it up. The big issue is the owner states it will not go over 15 mph. I have not done a full and complete inspection on it yet. After taking 5 minutes to get it started I was able to build some rpms in the engine by working the throttle under the hood "very slowly", if I twisted the throttle even a little to quick the engine choked and died. The only time I have seen one run so bad and choke out so fast is with a clogged cat converter. Like I said, I'm buying it no matter what due to the deal I will be getting, so this is for advice on possible other issues that could cause such poor throttle response.

 

cat would be my guess on in.

 

Cat sounds right , could be fuel filter- if was the same one installed at factory, fuel pump not typicaly, they tend to be all or nothing,check with Blue XJ , he has the know on renix

 

Bought it anyway, who can argue with 350$ for a virtually rust free XJ with a 3 inch lift already installed.