New jeep owner's jeep troubles

[cdrake261]

Hey guys, just got my jeep about about two weeks ago...it's idling rough, especially below 1k rpm and mileage is in the dumps(currently unsure other then I seem to lose 1/8 of a tank for an 16 mile drive). It has new distro rotor, distro cap, wires, champion copper plugs, crank position sensor, and cam position sensor but I still keep getting rough idle, missing, rich fuel coming out of the exhaust, and engine code p0340 and p1391. I need help here, I can't afford to replace everything until I get a better job soon.

 

[akelts]

My guess would be O2 sensor or the wires to it may be grounding out on something. I would do a search on the codes first though before buying any new parts.

 

[cdrake261]

My guess would be O2 sensor or the wires to it may be grounding out on something. I would do a search on the codes first though before buying any new parts.

Both codes suggest cam position sensor and crank position sensor...both of which I replaced

 

[FlexdXJ]

Hey Caleb, sorry I didn't get back to you on facebook yesterday. I was busy helping fix my little incident and pulling a motor. Check the 02 wiring like the other guy said. Couldn't hurt. A misfire on an XJ is kinda hard to diagnose sometimes. Not saying its the case but my buddy just bought a 97 that seemed like it was missing for some reason he couldn't pin point until he took the head off and found a hole in the piston. Try a compression and leak down test on the cylinders to rule that out.

 

[cdrake261]

Hey Caleb, sorry I didn't get back to you on facebook yesterday. I was busy helping fix my little incident and pulling a motor. Check the 02 wiring like the other guy said. Couldn't hurt. A misfire on an XJ is kinda hard to diagnose sometimes. Not saying its the case but my buddy just bought a 97 that seemed like it was missing for some reason he couldn't pin point until he took the head off and found a hole in the piston. Try a compression and leak down test on the cylinders to rule that out.

It's cool, trying to figure out my engine woes...almost like beating my head against a brick wall

 

[XJosh95]

Maybe vacuum leak? Don't forget about injectors. Running that rich could be an injector stuck open.

 

[altrocker1]

CHECK O2 wiring x10000

i had very similar symptoms and got codes for cps and cam position sensor...had a blown o2 heater fuse and some bad wires in the system. took care of it 100% when i fixed them.

before you do anything...what year is your jeep? if it has a fuse block under the hood, check the fuse for the o2 circuit before you start dropping more money in it.

 

[FlexdXJ]

CHECK O2 wiring x10000

i had very similar symptoms and got codes for cps and cam position sensor...had a blown o2 heater fuse and some bad wires in the system. took care of it 100% when i fixed them.

before you do anything...what year is your jeep? if it has a fuse block under the hood, check the fuse for the o2 circuit before you start dropping more money in it.

Its a 98, been trying to help him out for a couple days with it. Caleb it should have a fuse and relay for the ASD(auto shut down) circuit.

 

[99SJ_Ex]

Wow.... This sounds a lot like what my pile was doing.... IGNITION COIL, check it!

 

[altrocker1]

if its a 98 then it has a fuse for the o2 sensors in the box under the hood...its one of the small fuses. check the diagram thats on the lid of the box. its for other things as well, but i don't think its paired with the asd circuit. when mine was bad, the engine would rev erratically, stumble like crazy, and almost stall when you would take off from a stop. anything that affects the 02 sensors effects mileage

 

[altrocker1]

Wow.... This sounds a lot like what my pile was doing.... IGNITION COIL, check it!

yes check the coil...but check the fuse first!

fuses are cheap

 

[cdrake261]

Haven't checked the asd or the o2 sensor yet but I checked the fuses under the hood...those are good. I was considering replacing the coil, would a bad coil produce the p0340 and p1391? Would a faulty o2 sensor produce those errors?

These bad mileage are killing me, and I'm just about stock...

 

[cdrake261]

Haven't checked the asd or the o2 sensor yet but I checked the fuses under the hood...those are good. I was considering replacing the coil, would a bad coil produce the p0340 and p1391? Would a faulty o2 sensor produce those errors?

These bad mileage are killing me, and I'm just about stock...

Any ideas anybody?

 

[87manche]

checked the fuel pressure?

 

[Rev Den]

First....breath.


Second....check the things that this group tells you to, collectively we have been through all of this before.

Third....breath.


Rev

 

[cdrake261]

First....breath.


Second....check the things that this group tells you to, collectively we have been through all of this before.

Third....breath.


Rev

I'll try...going to check fuses again to be sure I didn't overlook any bad fuses.

 

[cdrake261]

checked the fuel pressure?

I have not yet

 

[cdrake261]

No blown fuse...I'm gonna need to get a new multimeter, my old one bit the dust unfortunately.

 

[cdrake261]

Haven't been able to work on the jeep since last saturday, but I checked my mileage and got 10.6mpg between Columbus and Nashville...seems really low for highway mileage, don't you say?

 

[Rev Den]

Lift?
Tire size?
Gears?
Man or Auto?
How fast on the hwy?


Rev