I have a 1996 Jeep Cherokee sport 4.0 205k miles

Here’s what’s been done already.. mechanic shop replaced cps sensor (non-mopar) and throttle position sensor... there is also a leak in the manifold.. that I was told would not cause issues short term..

The problems: will loose power when accelerating.. misfire occasionally.. and takes 4-5 separate attempts to start up the vehicle...

Codes that the check engine is throwing me:
p1391 camshaft position sensor severity 2 of 3
p0123 throttle position sensor “A” circuit high

To Note: have a feeling this shop definitely ripped me off a little, unfortunately I was in a pinch and looking for a quick fix.. you live you learn.. hoping to tackle this problem on my own now. Also check engine has been on since it left the shop but has various driving patterns.. some days good some days not too great.. exhibiting more of the problems stated above^ Some days it drives perfect with no problems.. also hasn’t had codes come up until today and I’ve had the vehicle driving for the past two weeks.. checking for codes every other day and it finally popped for the 2.

What I’ve ordered: exhaust manifold and mopar crankshaft position sensor..

Please help!! Will install the two parts sometime early next week when they arrive but any advice on what else to check/do in meantime would be greatly appreciated.

 

Which manifold has a leak? Neither one is good and neither one is fun to fix.

While you are waiting for parts you can get it ready for the new parts to be installed.

 

Exhaust manifold has a leak in it, and I’ve heard! Haha

 

I would check the fuel pressure 1st.

 

Fuel pressure is at 45 while running.. seems to not be the problem I’m really stuck on what is.. will probably replace the fuel filter here as well see if that helps at all.. when I turn on the vehicle I can hear the fuel pump initiate

 

Never a bad idea to replace an old fuel filter,, but if it has 45 PSI while running, fuel is good,, pull clean test the injectors.

1st do a compression test, if thats good check the injectors, then hook a monitor up and see if it shows any thing. sometimes it's best to pay a mechanic to monitor it whith a high dollar monitor,, cheaper than loading the parts cannon

 

Which sensor? The error is for the cam shaft sensor. The crank sensor (what most people incorrectly call the CPS) is different. The crank sensor will often not set a code, or set just a code for the camshaft sensor.


In the interim, cheap and easy things to look at are:
- Check and clean all the ground points you can find. In particular where the wires connect to the engine block by the dipstick.
- Inspect the wiring at the back of the engine where it comes up from the crank sensor and across from the injectors for damaged or melted wiring.
- Wiggle the wiring harnesses with it running to see if you can make it stumble.
- Also (because lightening does strike twice!), make sure the belhousing is still bolted up tight to the engine.
- If you have a multimeter, test the TPS. In particular that it has a good ground at the sensor.

 

I didn't do this myself, but this is what I would say to a beginner with a Jeep.


1) The smarter you are in the beginning while working on your Jeep, the more affordable your vehicle will be. Sometime the best tips you will get will be in person.
If your jeep is becoming expensive with repairs its probably because you are letting it happen and not being smart about working on your Jeep.
2) Hanyes Manual <- I think that is the name, its a manual about Jeeps you need it. I wish I got one.
3) Bleepin Jeep <- Some youtube channels are great for learning about your Jeep
4) If you choose to keep your Jeep you will end up spending a lot on tools probably over time need over $200 worth of tools <- Walmart has some tools on sale now maybe just go ahead
and get a tool box with about (more or less) 100 pieces in it. <- I have waisted a lot of money on tools not thinking when buying tools, so I might not be the best person to ask lol.
Also wrench's are great.

Don't rush on projects unless you have to, when you rush things go wrong. Working on your Jeep is fun. It will teach you how to follow instructions and if your instructions are correct.
Think about what you are doing, it will help your learning curve and help you in the future to work on your own. One time I had to hire from craigslist and that helped a lot.

 

Forget the Haynes, it's garbage and often flat out wrong. Google for the 1996 Cherokee factory service manual (posting the links here is verboten, btw). $20 will buy a nice multimeter. Even the cheap meters at Harbor Freight go on sale for $1.99 occasionally, and are nice to keep in the glove box or give away when someone wants to borrow my expensive meter. Some basic knowledge on how to test parts instead of blindly replacing them will save you a bunch of time and headaches. Especially when the aftermarket parts are often in worse shape than the part you're replacing.

 

This is probably a bit more helpful than my post. I don't test parts I just replace them. Oh well.

 

Arggggh! I can't count how many times, I've helped someone who "fired the parts cannon" only to figure out the original part was just fine and the new one was bad. Or had to replace that cheap new part 6 months later.

 

Diagnosing is more complicated and sometime you diagnose and think you are right.