Finch

Hey guys, i recently got a very clean 2001 XJ Limited 4.0l (even has fricken heated seats and ice cold ac hell yea!!) from an auction. The truck has 230k and runs good BUT has a cylinder 6 misfire. I ran injector cleaner through it and it seemed to help ALOT. So im just going to replace them. What are my options here and does anyone sell a complete rebuilt set. What other things should i look for?

ryan8551226

Programbo sells them on here. Get a set of four holed ones. I think they are called 784 injectors.

ryan8551226

He rebuilds and cleans the hell out of them

xjsnake

Here ya go.

rockstomper92yj

Not so fast with the injector problem! Are you sure its the injector? Have you pulled the injector rail and tested them? Pull the rail and leave them in tact place a piece of cardboard under them and prime the pump with out cranking the motor over. if you get a pool of gas? or switch the injectors to see if the misfire jumps locations? then yes you have an injector problem.
My coil pack had a broken connection just on #6 and that was all it ended up being. are you throwing any codes?

Finch

Unfourtunetly i switched injectors and the problem persisted Cylinder 6 misfire. im going to get a new coil pack next check to see if that helps if i can figure this out im still going to upgrade the stock injectors

Kalali

Single cylinder misfires are rarely caused by a faulty coil pack. I would rule everything else out before spending (~$120) for a new coil pack. Your money your choice.

Finch

Should i be looking at internal engine? And for what i got this for i have no issue fixing common ware stuff

ryan8551226

Have you checked your sparkplug?

Finch

No tomorrow im going to tear it apart

MrTowers

always always ALWAYS check the simple stuff (free or low cost) first. Misfire in one cylinder? You did good by swapping injectors. Next would be checking plugs, then check spark in that coil. If nothing there solves it, you might want to check compression.

Finch

Replaced all 6 plugs with OEM Champion Coppers and put a new coil pack on it and it seems to be fixed but still has a bouncing idle. Im sure the injectors are toast by 230k so im still searching for options

MrTowers

my 01 limited has the same bouncy idle your talking about it think. im not throwing codes and when driving it doesn't seem to be messing with anything so i stopped digging for the solution. i replaced the brain box, everything tied to the ignition system, chased down grounds, chased down vacuum leaks, played with my exhaust (thinking maybe the straight pipes the guy before me had on it was causing havoc, it was) and still no fix. just said im done lol

salad

What's "bouncy" mean? Bad TPS can cause the IAC to hunt and you get fluctuating RPM. Vacuum leak can also do that.

For reference, on coil-on-plug 4.0Ls coil fire the spark plugs in pairs. Bad coil will cause neighboring misfire.

Also Chrysler discontinued the use of RC12ECC in the distributorless 4.0Ls and switched to NGK ZFR5N. Durability issues with the Champions apparently.

What do you mean there were straight pipes on there before? How much of the exhaust was bypassed?

Finch

Well after 500 miles of driving the little bastard light came on. The code i now have is a p0432 code. No more misfire tho!!! Main catalyst efficincy bank 2. Could the fact the po drive it with the misfire and that hurt the converter?