TJ sputters while accelerating

[Rick C]

Details:
2004
130,000 mi.
TJ 4.0 I6
new plugs
new coil rail
new cam sensor
fuel system cleaned
No Check Engine Light
dealer's scan shows NO codes
The above was performed by Jeff Wyler Jeep in Canal Winchester Ohio

The Vehicle sputters when accelerating once it warms up a few minutes. Then runs fine when up to speed.
Also smells like it is running hot but temp gauge shows 210 degrees no signs of coolant leaking.

clogged cat maybe?

I'm stymied.

 

[Jerry Bransford]

Bad upstream O2 sensor. Replace both upstream O2 sensors with either NTK or NGK brands, not Bosch. What you're smelling is the extra rich fuel mixture caused by the bad O2 sensor.

 

[Rick C]

I just ordered (2) NTK 23137. $26.76 ea. Hope that's the right part.
Thanks for your quick reply.
RC

 

[Jerry Bransford]

I just ordered (2) NTK 23137. $26.76 ea. Hope that's the right part.
Thanks for your quick reply.
RC

Not quite, you need an NTK 23137 for the front (bank one) and an NTK 23135 for the rear (bank two). https://www.rockauto.com/en/catalog...01,exhaust+&+emission,oxygen+(o2)+sensor,5132

 

[Rick C]

Up

 

[Rick C]

Jerry.
Thanks for your insight. I have ordered the 23135 sensor which means I will have a 23137 extra if you need it.
Now I just need to find a good mobile mechanic to install these. I've attached a picture of my left foot which explains why I have a difficult time climbing under cars

 

[qslim]

Jerry.
Thanks for your insight. I have ordered the 23135 sensor which means I will have a 23137 extra if you need it.
Now I just need to find a good mobile mechanic to install these. I've attached a picture of my left foot which explains why I have a difficult time climbing under carsView attachment 166284

Ooof, yeah I bet that's a pain. Do your mobile mechanic a favor and, if you can, douse the existing 02 sensors with some penetrating oil (Kroil works great) a day or two before he comes by. That'll help those sensors come out nice & easy. Hell, if you have a neghborhood kid with a 22mm wrench that wants to earn 20 bucks they could probably knock it out for you too.

 

[Rick C]

Thanks.
I gave some PB Blaster and an O2 socket left from another project. I'll let you know how it goes.
RC

 

[Jerry Bransford]

Kroil, Liquid Wrench, and Break Free are all significantly better choices for that job than PB Blaster is which is little better than WD40.

Slotted O2 sensor sockets are great for installing new sensors but that slot makes them too weak to remove an old seized O2 sensor. Use a standard 7/8 socket or closed-end wrench for that often very difficult job. Get the engine good and hot to help make it easier to remove the sensor.

 

[Rick C]

Well I replaced the two upstream O2 sensors with the recommended NTK products and still have the issue. When I accelerate very slowly the jeep doesn't sputter as badly. Just like before the new sensors. Fuel pump/filter maybe?

 

[Rick C]

		There is also a Prestige remote starter installed that may be doing weird things with the ECM. I'm going to disconnect it tonight and see what happens.

 

[Rick C]

		There is also a Prestige remote starter installed that may be doing weird things with the ECM. I'm going to disconnect it tonight and see what happens.

Disconnected the remote start module and the issue persists. I think I'll drop the tank and replace the fuel pump and filter.

 

[qslim]

Have you measured fuel pressure at the rail?

 

[Rick C]

Have you measured fuel pressure at the rail?

No. On the 2004 there is no valve stem on the fuel rail so I don't know how to do that. Need the tool also.
The problem is getting worse.

 

[Jay MacLeay]

No. On the 2004 there is no valve stem on the fuel rail so I don't know how to do that. Need the tool also.
The problem is getting worse.

I was having this same issue and I found that the timing chain had a slight bit of slack in it. I replaced the timing chain and the issue went away for awhile. The issue is back again, though.

Rick, did you ever figure out your issue(s) ?

 

[macleanflood]

Exhaust leak could cause this issue too...not all the gasses getting to the O2 sensors.

I'd bet money on cracked headers.

-Mac