My 89 xj 4.0 has a hesitation when u accelerate but once u get up above a certain rpm it clears up could this be an injector problem or something else

 

Last complete tune up was ?

 

Was just done when I got the truck last week

 

Just curious, What brand of plugs did you put in and are they gaped at .035? I know when I put in some high priced Bosch plugs my XJ had the same problem. So, I took them out and put back the Champion plugs and it ran great.

 

Bosch I think

 

Yeah, The 4.0 seems to run much better with Champion Copper or NGK Copper.

 

Important question is did you have this symptom BEFORE your tuneup? Did the tuneup include plugs, wires, cap, rotor, fuel filter?

There are lots of possibilities for hesitation, but I'll have to agree with RTorrez about Bosch plugs. Some, (not all to be fair) have had some issues with them which have been resolved with a different brand of plugs, predominantly Champion coppers. That's what I'd recommend.

 

TPS would be next to check, fuel delivery issue, CPS, to name a few.. But its a Renix, which I have no right getting into.

Cruiser54's Renix tips already eyeballed?

 

G'day mate!!

The link to my tips is in my signature below.

 

Good morning, good you're here, so now I can go to sleep

 

You're so full of it!! LOL.

 

But I mean no bad Just tired.

 

I know. Get some sleep. I'm going to work soon.