2005 Jeep Liberty Sport
3.7L with 6 sp Manual transmission.
44600 miles

Filled up tank with gas and drove to store. Finished shopping and started my Jeep and was on my way.

Shifted into 2nd gear and when engine got to about 2200-2500 RPM the Jeep started jolting and I immediately noticed the engine would not rev over about 2200-2500 RPM.

I thought at first it was the clutch dieing but I then tried full clutch lift while hitting gas. Once the revs got in the low 2k range it would not go higher...like the rev limiter was on.

Once I got back to work I thought I would turn engine off and restart to see what happened. I tried this and it started fine and would now rev to normal RPM. Chalked it up to computer hiccup.

Upon leaving work later the Jeep started fine and would rev but I noticed the check engine light was on and would not go off. It seemed to run, accelerate and behave normally.

Once I got home I checked fluids etc and thought maybe flashing the PCM by disconnecting battery would have an effect. ..Still hoping it was a computer hiccup.

Nope.

Sometimes when it starts the engine will rev and everything seems fine but with engine check light on. Other times I will start it and the engine runs noticeably rough with the RPM limited to 2200-2500 RPM with the check engine light on.

Any suggestions as to what is going on?

Diagnosing electronic engine issues is not my forte. I haven't any ideas and don't know where to start. I dread taking it to a dealer.

Thanks.

John
];')

_________________
05 4x4/3.7L/6 Spd
245/75R16 GY Dura Trac
Lots of Mods!
My Wheeling Videos
My Mods, Upgrades and Custom Fabrications

Went over to Autozone and they hooked up their diagnostics computer and got a code P0202.

Gave reasons: Fuel Injector circuit condition - injector # 2

- The powertrain control module monitors the fuel injection electrical circuit for opens, shorts and system overload conditions.

- 1 Open or shorted fuel injector(s)
- 2 Open or short in electrical circuit
- 3 High fuel pressure-pressure regulator defective-fuel return line blocked
- 4 Check TPS circuit for failure

So after checking the wires for issues should I just go ahead and replace the injector and TPS?

Anyone ever had issues with the injector wire harnesses?

Wouldn't the fuel pressure regulator cause more than one cylinder to have issues and therefore it is most likely the #2 injector or the TPS? The injector and TPS cost less than $80 together and would be easy to replace. from what I can see under the hood.

Any suggestions/tips on which way to go?

Thanks,

John
];')

_________________
05 4x4/3.7L/6 Spd
245/75R16 GY Dura Trac
Lots of Mods!
My Wheeling Videos
My Mods, Upgrades and Custom Fabrications

In doing some research on the diagnostic engine code P0202 I found that a lot of people with Jeep Wranglers and Unlimiteds with the same or similar symptoms and check engine codes solved the problem by replacing the TPS.

So I went ahead and bought a new TPS from Autozone for $28 and replaced it. I also changed out the plugs and other maintenance while I was at it.

Started it up and check engine light went out almost immediately. Seems to be back to normal. Takes less than 1/2 hour (15 min) to replace just the TPS....then plungs...yeech!...a bit longer...lots of stuff to move out of the way to make accessing the plugs easier.

John
];')

_________________
05 4x4/3.7L/6 Spd
245/75R16 GY Dura Trac
Lots of Mods!
My Wheeling Videos
My Mods, Upgrades and Custom Fabrications

YEY! Good job using google

_________________


05 CRD Sport Dark Kahki

RRO: Adventure Rack/Rails ** MOPAR: Skids/Renny Flares & 255/75r17 (32.1) BFG M/T on JK wheels ** ARB: Bumper/IPF lights/790/948/shocks ** GDE: TCM/Hot Tune ** ROCKLIZARD: Super Sliders/Komodo Bumper

My Build Thread
US Army Infantry