Ok so you may have seen some of my posts regarding my 94 with a 96 engine Cherokee that used to start up every time...but then went ***** down when I installed fog lights which I uninstalled, then re installed because it is not the problem. But now my mechanic has the cherokee..going on a week and a half plus tomorrow and he can't get it running. The camshaft position sensor wires were shorted so I redid them and then he replaced it, along with the distributor and the crankshaft position sensor.. He does not usually work on older vehicles but he is a good friend and did the engine swap for me. I was able to get it running after I re-spliced the camshaft position sensor wires but only once in a while it would start. And if it started it would stay running for me. I turned it over to him and he did those things and he can't get it running. Fuel Pressure is good. Seems to be an I dont want to spark situation. I have done research so much my head is going to explode. I don't even know if we can curse in our posts but I normally do. Anyway I bought this thing on ebay that is an obd1 to obd2 converter...just a wire setup that works with some vehicles. However it may work with his mega Snap-On code reader. Anyone ever try this? At this point I am not happy and want the truck back so i can just try to fix it myself. I told him I would pay him whatever he wants...and he was like ehh I will see what I can do. My best mechanic friend man...can't even work on it. I am done if he does not fix it by Saturday. We got a big storm comin in nj this weekend. I have been building this thing just for this winter.....and the next...and now it just sits in his lot. I have read all of your suggestions in many posts and I dunno what the hell to do but I am not gonna let it sit there for another dam week.

 

You mechanic wants the car to tell him what to do via OBD codes. Good luck with that, it's not going to happen. This is why he doesn't work on older cars.

Do you even know definitively yet if it is the spark that is dropping out? I noticed fuel pressure keeps getting mentioned. I thought you were beyond all that already. I've read all your earlier posts, but don't remember every detail because they are spread out across multiple threads.

 

Well from what he has told me he tested the fuel pressure and it is good. I am not inclined to disagree on that. I would have to say the spark is dropping out because of something unknown...and you are right my mechanic does not like older vehicles. I believe he worked on this because we are good friends. Anyway I did my own tests with relay swapping before I gave it to him....since the ASD and other relays are the same. No change. But that was on my end. Now I don't know what level he is at. But I just sent him some messages saying if he can't get it running by saturday I am taking it back. I literally told him I would pay him whatever he wants to get it running. I think he does not want me to do that and just keeps avoiding it. So I broke it down and said I could push it into your shop myself...he told me today he can't really move it and has other cars to do. Yet he has 3 plus guys working with him on a flat surface. It rolls fine in neutral...I hate to be in this position...he is the best mechanic I ever had and a great friend....but this is too much for me. I can't offer open ended money and get nothing.....that is insane! I will have to find and call up a new mechanic...at least I know what I am talking about so he can't BS me.

 

I mean this in the nicest way possible but it’s never a good idea to have a friend be your mechanic. The 4.0 is about as basic at it gets diagnosis is simple. First and foremost you need to calm down and start back at the basics . Fuel , spark , compression .

 

No I totally agree and that is what he did....I think unfortunately there is some corroded wiring in the hideouts and that is what he is missing. I hear you though. But he has done many things for me...first time I brought him an old xj though. oye

 

Well here is today's update,, I sent my good mechanic friend a drunk text message and laid a guilt trip on him. When I got up this morning I felt incredibly terrible and sent him a message to apologize. Either way apparently being a drunk Ahole gets things moving cause he worked on the truck all day and when I got there at 530 they were still having trouble but he picked up a whole different distributor and different style camshaft position sensor. It had great spark, great fuel pressure, but he showed me this test light connected to a plug next to the fuel rail. I forgot what it is called...he said if that does not light when the engine turns over it will not work. Apparently when I showed up he had just installed the new stuff....and the light started working but would stop when given gas. he must have had an epiphany cause he ripped apart the distributor and reseated it while setting the motor at tdc I believe...after he put it back together it started right up! So i am crossing my fingers he said he will try to button the engine up tomorrow and he will let me know. But she lives again! I am just a little upset with myself for ripping on him but whatever. I brought him cookies so he can forgive me. And that is your update on my cherokee saga...

 

Okay Next update...Jeep is running strong and I am picking her up tomorrow morning. I had a late lunch with my mechanic buddy and friends. Afterwards we were experimenting with the transmission. I know more about it than he does so he was like you can have it back, you seem to know more about this than me.. haha.. I was okay with that. I am fairly confident I can get her to shift right with some more custom adjustments. I am just happy my mechanic and I are good friends again. It was a rough deal. So She is running again....Starts up first shot...tons of horsepower....onto the shifting. Rough couple weeks but I am happy and so is my friend. Crazy few days

 

The two things that come to mind for your XJ are the TV cable adjustment and the throttle position sensor. More on those below. The first is a link to TV cable adjustment and below that is a "cut and paste" I made up on how to verify your throttle position sensor which is very involved with the shifting characteristics of your AW4 transmission. Start there. Good luck; quite a saga for you!
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https://www.cherokeeforum.com/f2/free-quick-fix-41821/

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The throttle position sensor is connected to the throttle shaft on the throttle body. It sends throttle valve angle information to the PCM. The PCM uses this information to determine how much fuel the engine needs. The TPS is really just a simple potentiometer with one end connected to 5 volts from the PCM and the other to ground. A third wire is connected to the PCM. As you move the accelerator pedal with your foot, the output of the TPS changes. At a closed throttle position, the output of the TPS is low, about a half a volt. As the throttle valve opens, the output increases so that, at wide open throttle, the output voltage should be above 3.9 volts. Testing can be performed with an electrical meter. Analog meter is best. You are looking for a smooth sweep of voltage throughout the entire throttle band. While slowly opening and closing the throttle, take note to the movement of the voltmeter needle. There should be a direct relationship between the needle motion to the motion of the throttle. If at anytime the needle moves abruptly or inconsistently with the movement of the throttle, the TPS is bad



You should have 5 volts going into the TPS. At idle, TPS output voltage must be greater than 200 millivolts. At wide open throttle (WOT), TPS output voltage must be less than 4.8 volts.. The best is to use an analog meter (not digital) to see if the transition from idle to WOT is smooth with no dead spots. With your meter set for volts, put the black probe on a good ground like your negative battery terminal. With the key on, engine not running, test with the red probe of your meter (install a paper clip into the back of the plug of the TPS) to see which wire has the 5 volts. One of the other wires should show .26V (or so). The other wire will be the ground and should show no voltage. Move the throttle and look for smooth meter response up to the 4.49 at WOT.



Perform the test procedure again and wiggle and/or tap on the TPS while you watch the meter. If you notice any flat spots or abrupt changes in the meter readings, replace the TPS.



The TPS is sensitive to heat, moisture and vibration leading to the failure of some units. The sensor is a sealed unit and cannot be repaired only replaced. A TPS may fail gradually leading to a number of symptoms which can include one or more of the following: -



NOTE: The throttle position sensor is also DIRECTLY involved with transmission shifting characteristics! It should be verified early in the troubleshooting process, when a transmission issue is suspected!

• Poor idle control: The TPS is used by the ECU to determine if the throttle is closed and the car should be using the Idle Air Control Valve exclusively for idle control. A fault TPS sensor can confuse the ECU causing the idle to be erratic or "hunting".
• High Idle Speed: The TPS may report faulty values causing the engine idle speed to be increased above normal. This is normally found in conjunction with a slow engine return to idle speed symptom.
• Slow engine return to idle: A failing TPS can report the minimum throttle position values incorrectly which can stop the engine entering idle mode when the throttle is closed. Normally when the throttle is closed the engine fuel injectors will be deactivated until a defined engine RPM speed is reached and the engine brought smoothly to idle speed. When failing a TPS will not report the throttle closed and fueling will continue causing the engine to return to idle very slowly.
• Engine Hesitation on Throttle Application: The TPS is also used by the ECU to determine if the driver has applied the throttle quicker than the Manifold Air Pressure sensor can read. The fueling is adjusted accordingly to cope with the sudden increase in air volume, however a faulty sensor can cause the ECU to ignore this data and the engine will "hesitate" when applying the throttle. In extreme cases with the engine at idle, a sudden application of full throttle can stall the engine.
• Engine Misfire: A fault TPS can report values outside the denied acceptable range causing the ECU to incorrectly fuel the engine. This is noticeable as a slight misfire and can trigger the misfire detection software and/or Malfunction Indicator Lamp (MIL) light on the dashboard. Extreme cases can cause excessing misfires resulting in one or more cylinders being shut down to prevent engine and catalytic converter damage.

 

Gettin ready to sleep but thanks man...pickin her up in the early morning. Appreciate any info thrown my way on the tranny.!

 

So I got my Jeep back....did an oil change to clean the engine(used seafoam earlier to clean it) Put in Rotella T6 5w40 with a Mopar filter(sorry not a wix) She is pretty much purrin like a kitten on crack(glasspack muffler). Did many experiments with the transmission...still hit or miss. But I do know what a TVC cable can do depending on its location. Pretty amazing. If it is at about barely pushed out..It will shift into drive hard and never leave first gear. So as it got further out I had a better chance of the automatic transmission shifting again. But it was not really. So I maxed it out past the reset method and I was able to get it to shift but only at high idle. I reset it again today and it is not all the way out but it seems to shift a little better...Certainly not the way I have had this thing shift before. It is still shifting and holding high RPM's to get to the next gear after I back off on the gas at speed. TJWalker I know you mentioned the TPS but none of those symptoms apply to my Jeep. The engine does not hunt, I dont have trouble with hesitiation or high rpms holding and def no misfire. Now being that this is a 96 engine with a 94 transmission could the tvc cable just not interact correctly? Or do I have to replace the solenoids. Would a big name transmission place try and screw me saying I need a new trans(I know I do not) I mean I thought about going to one and if they bs me i can School them to hell since I have done so much research. I dunno right now. I can get her to shift and she runs like a beast again but I do need to fix the trans. I am burnin gas like crazy with those rpms haha....So glad to have my baby back!

 

So I was going to take the jeep out to get some beer...and see how she was doing. I had her all packed and ready for work tomorrow. And I turn the key and she WILL NOT START! AGAIN! Same conditions. Cranks like a beast but will not engage. I thought I was over all this and now I am all the way back to wtf? All that work my mechanic did and to have the same condition reappear is insane!
Here is what I did yesterday. I had her fully heated up, drained the oil, removed the filter...Put in a new mopar filter, added 5 quarts of Rotella T6 5w40 and 1 quart of Lucas oil Stop leak.(its like molasses but works great) threw her back together and she fired right up...sounded much better in a few minutes with the fresh oil.
Next I had to fix the wipers because one was off set and also I had to fix one of the washer sprayers. All done works great.
After that I was concerned that I had a slight knock and thought it might be the flexplate bolts. So I removed the flexplate cover and checked each bolt and they were all tight. I reset the flexplate cover and bent it out a little cause I ran the engine without it and it seemed quieter. Reinstalled flexplate cover and still managed to maintain the quiet.
One thing I noticed, I had the engine running with the flexplate cover off and while it was spinning under my flashlight it looked slightly bent. Very slight, not what I expected from a big giant toothed gear. Either way the engine was running smooth so I buttoned her back up. I mean while then engine was off I did have to rotate the flexplate with a wrench to check each bolt...but it started up fine after that so I do not think that was an issue. Still a curiosity though.

last but not least were the many transmission cable tests. I tried many positions, at one point even altered the idle on the throttle body, but it was too low...so I put it back. Still she started first crank every time. Took her to the gas station and filled the tank with supreme...and drove her home. She was running all day for several hours. On and off, always starting.

My friends, I cannot put this kind of pressure on my mechanic again. I want to fix this myself. Originally he showed me there was a problem with the injector pulse. They were not firing(he had a test light) then while I was there with his 2nd camshaft postion sensor and 2nd distributor which he rotated...the injector pulses became perfect. After that she ran great. I am at a loss. The mechanic and I were both thinking of replacing the pcm. Is that the next move? I will buy anything at this point but I don't even want to tell him it is not running. It kind of means everything he did had nothing to do with the original problem..which is insane.

At this point any advice is great. I will buy any part, or any tool I don't care. By the time I am done i will be a full blown Jeep Mechanic! Help me Obi One Kanobi! yer my only hope~!

 

How were these connections/wires repaired? Butt connectors by chance?
Did you ever clean whatever connector you mentioned before?
Wiggle wires and see if it starts. If it does, wiggle them til it dies. that's how you pinpoint issues.

 

tjwalker you are the man! When my truck does run...still working on that...might be okay now...it had the serious shifting issue. So I did the wrong thing and bought every sensor I could. Today she was running okay and I replaced the MAP sensor which was interesting because I think it made a big difference. But every test drive was a nightmare no matter how many times I adjusted the tvc cable. So I was like f-it, let's do the new tps(I got one of everything) and see what happens.

BAM! Perfect shifting immediately after replacing the tps! I was like wtf? The only other thing that changed was the idle went lower. But not to a stall point or anything. Now she starts and shifts great. I will not hold my breath about the starting until it is consistent but I am confident the tps fixed the shifting!!!!! THANK YOU tjwalker!!! You should put more in your info about how the tps can affect shifting because it did not really have those symptoms...but wow. Tomorrow is test day 2. Mostly start checks. Can't drive it until I know it will stay running. Just chillin now. Wow crazy day.

 

Glad I could be of some help here! Enjoy your posts, can feel the enthusiasm! Now that the shifting problem is (hopefully) behind you, onto the starting issue. Keep us updated and if you still have trouble, post here with a summary of where you are at / what you have done and we'll help you if we can. Rock on man!