I have a 2000 Cherokee Sport. Engine light is on.

So my Jeep starts right up and runs great. Then after a few minutes the engine becomes sluggish and the Jeep starts "chugging"....kinda like a misfire.

Any ideas what would cause this when the Jeep warms up, and not immediately upon start up?

Got the Jeep scanned this wknd, and the following codes were pulled:

P0201 - Fuel Injector Circuit Condition (Cylinder #1)
P0301 - Cylinder #1 misfire
P1494 - EVAP Leakdetection pump pressure switch condition

Lat year I had the injectors replaced when I got the same codes, and all was fine for about a year. FYI - the Jeep runs fine until it's warmed up, then it starts misfiring.

thoughts?

 

Try swapping the injector in cylinder 1 with another. If the problem clears up, you know it's the injector. If not, the wiring is suspect. Chafing and broken wires are not unheard of along the wiring harness.

Not sure about the evap stuff.

 

Where specifically, shall I look? Which wiring harness?

Thanks!

 

I have found that many of the wiring harnesses that run along the top of the intake begin to melt and fuse together. Open up that plastic wiring retainer that contains all your injector wiring.

Do you still have a heat shield on top of your intake?

 

The injector wiring harness runs between the fuel injectors and valve cover and then makes a jump to the firewall. Open your hood, it will be obvious

 

Can you just pop them off and switch them out?

 

Vacuum leaks can cause this sort of problem and codes.

Inspect the LDP (leak detection pump) & intake manifold, look for a loose, missing, broken/split vacuum hose. Also the wiring & connections for the LPD.

Possible cause of a P1494 is a vacuum leak, poor / intermittent connections to the LPD, faulty LPD ...

 

Does anyone know what goes here? Could this be causing these codes?

 

Nice vacuum leak. That's supposed to be blocked off on 99+ XJs.

 

So just cap it?

 

Yes, there's supposed to be a little rubber cap that goes on it. You can just plop a dab of RTV on it. Don't start the engine until it cures

 

Hmmmmmm....in other forums, some people are saying that there should actually be a hose there. I put my finger over the hole while idling and the Jeep almost stalled out.

Refer to the LDP diagram below....I can't really make sense of it....can you??

 

Not any XJ I've seen... I can go take pictures of my 1999 and 2001 for you if you really want. Same as the pics you'll find on Google.

That diagram only has two connections made to the intake manifold.

 

Here's a pic of mine

 

You haven't capped that fitting yet??