Hello every one, Me and my brother have been stumped on trying to get his 2001 Jeep to get running properly.

The biggest symptom right now is the fact it doesnt get above 3k rpm.
It has trouble starting, but ive had the battery on a charger for the last couple of days. Therefore it should start with out a hitch.
When it does start, i sits around 300-500 rpm for the idle. Turning on the A/C Will kill the engine.

The parts that have been replaced are:
All the throttle body sensors
Fuel pump module
Crank shaft position sensor
Throttle positions sensor
Radiator and water pump
Power steering pump
Spark plugs
Coil pack
Air filter

Now for the things that are not on the Jeep are,
Any thing exhaust related past the first initial cat, so nothing after the forward most cross member ( fell out during driving one day)

So we have tired almost every thing, like as in talking through the problems, looking at it and tinkering with it.

Now it sits in my driveway, and i really would like to get this Jeep up and going for my brother.
Any thoughts? I’m open to discussion

 

questions,

Did it run right before you did all this?

Can you check fuel pressure to eliminate a fuel problem,

Does your throttle body butterfly operate smoothly from close to full open? TPS seated correctly? IAC working.

Coil over plug eliminates firing order issue, Can you put a spark checker inbetween somewhere to see if spark is breaking down. ( I have a 93 with a distributor so)

Air leaks unless large makes it run lean and so a high idle occurs.

All sensor wires seated.

A few pictures might help.

 

The Jeep ran fine before all of this happened. And tried to fix it but seems like I'm chasing. Just wanted to see what could be the issue

 

First thing to do with possible electrical issue, regardless of year, regardless of what's specifically going wrong, is to clean and tighten the grounds and battery terminals. This is obviously the big ones like the passenger side of the block (near the coil on older models), the battery to fender, etc, but also the one in the trunk behind the trim panel on the drivers side. Clean shiny metal, nice and tightly connected.

In your case, with several component parts recently replaced, I'd go through and make sure all of those connections are tight and the wiring is OK. A 20-year old Jeep is prone to wire sheathing drying out, cracking and potentially shorting out. If the XJ is anything like the TJ, as I recall, the connector for that coil rail unit was particularly painful to access and I've heard mention of an issue where it can come in contact with hot exhaust and burn the wiring back there. Something to at least check out and make sure all is right back there.

After that, you need to be damn sure you have a good battery as the XJ is particularly touchy about having a good battery. You can test it yourself for a basic test using a multi-meter or pull it out and run it down to your local parts store and have them load test it.

Once those are all confirmed, I'd start with the IAC valve and TB cleaning checks as mentioned previously.

 

Is the rubber elbow for the MAP sensor cracked? It's very hard to pull it off the pipe without damaging it and could have a vacuum leak in it. The computer needs to read manifold pressure to meter the mixture correctly and any air leaks could be making it run lean. Otherwise, you may have a bad idle air control, judging from the low idle.

 

What brand were all those new parts?

 

How are the oxygen sensors? How many you got/supposed to have?

Any OBD codes?

 

Is it running smoothly while this is happening, or does it seem like a cylinder (or more) are missing?

 

here......