Lots of problems

[HellionTJ]

Good morning


first off let me just say that I’ve been visiting this forum for a few months now as a guest, ever since I got my new to me jeep. I’ve been part of forums for many years now and I don’t want to be the guy that signs up and throws a bunch of questions regarding my CEL on my first post. I’ve noticed that you are pretty knowledgeable when I comes to jeeps.. I can’t find anyone local to me that is.. so I figured you could possibly be the guy I need to talk to..

Here’s basically what’s happened/happening.

I got the Jeep for free from a good friend that didn’t want to do brakelines and a windshield on it. It’s a 2002 TJ with a 4.0l and auto trans. I was getting a code for a thermostat last week so I decided to do a coolant flush, trans fluid change, diff fluid change, transfer case fluid change and oil change. I did all that last Saturday.

upon driving it Saturday night the CEL came on again. This time for an evap code, TCC solenoid code and a crank sensor code. I decided, since the Jeep was free, that I would put a new crank sensor and cam sensor in it, cause from reading on here they seem to be common fails. So I bought the sensors, cheap ones(I know I know, there junk). And when I road tested itafter the install, I started getting misfire codes. I then brought the jeep Back into the shop and swapped the cam sensor back to the stock on and it seem to run fine. Fast forward to the next morning the Jeep will not run. It’s shakes bad and as soon as I touch the throttle it stalls. I checked the codes and now I have codes for ignition coil primary circuits for 3 different cylinders.. I’m seriously at a loss here. I’m pretty mechanical but when it comes to wiring I’m lost. I’m planning to return the cheap sensors and get mopar ones and go from there. If that doesn’t help I’m going to pin the harness out.. also the vacuum line that runs under my battery was cracked so I just capped it on the line side, is that causing my any issues? I’m having an evap core also. Sorry for the long post, any help would be appreciated!

 

[HellionTJ]

Codes as of this morning after putting a new crank sensor in it with the old cam sensor.

 

[Chris]

First off, that shaking and then stalling, that to me sounds like a bad vacuum leak, which might make sense since you're throwing an evap code. I'd inspect all the vacuum lines, and if you can't find a leak, perform a smoke test to rule it out.

Next up, replace the camshaft and crankshaft sensors with OE Mopar sensors. As you know by now, these things to not like sensors other than Mopar, period. The aftermarket ones are all junk, and they more often than not will not get rid of the codes.

After you do that, test the coil packs, which can be done like this:



It also might not hurt to replace the spark plugs while you're in there. Refer to this thread for that: What are the best spark plugs for my Jeep Wrangler TJ 4.0?

 

[HellionTJ]

First off, that shaking and then stalling, that to me sounds like a bad vacuum leak, which might make sense since you're throwing an evap code. I'd inspect all the vacuum lines, and if you can't find a leak, perform a smoke test to rule it out.

Next up, replace the camshaft and crankshaft sensors with OE Mopar sensors. As you know by now, these things to not like sensors other than Mopar, period. The aftermarket ones are all junk, and they more often than not will not get rid of the codes.

After you do that, test the coil packs, which can be done like this:



It also might not hurt to replace the spark plugs while you're in there. Refer to this thread for that: What are the best spark plugs for my Jeep Wrangler TJ 4.0?

I just bought some Mopar sensors, they’ll be here tomorrow. Now when I was doing all the fluid changes in the weekend, my defrost was stuck on, I could change it to the vents or floor, I found that the vacuum line that runs under the battery tray was cracked. I ended up capping it off. Would the evap leak have anything to do with the canister under the battery tray?

 

[Chris]

I just bought some Mopar sensors, they’ll be here tomorrow. Now when I was doing all the fluid changes in the weekend, my defrost was stuck on, I could change it to the vents or floor, I found that the vacuum line that runs under the battery tray was cracked. I ended up capping it off. Would the evap leak have anything to do with the canister under the battery tray?

Yep, you've got vacuum issues my friend, I knew it. You don't want to cap those off, you need to get new lines and fix that issue.

The evap issue you're experiencing is very commonly linked to the canister under the battery tray, yes!

I think you're on the right track here.

 

[HellionTJ]

Is

Yep, you've got vacuum issues my friend, I knew it. You don't want to cap those off, you need to get new lines and fix that issue.

The evap issue you're experiencing is very commonly linked to the canister under the battery tray, yes!

I think you're on the right track here.

is there any pictures of what I’m supposed to look for under there? Is it inside the body?

 

[Chris]

is there any pictures of what I’m supposed to look for under there? Is it inside the body?

I belive @toximus had a really good photo (I think it was him at least) of the canister that sits inside the fender that is a very common issue for HVAC controls, and possibly evap leaks. It's probably in his build thread.

I haven't dug under the battery before personally, so I'm not sure what it looks like. Still, it should be as simple as tracing the vacuum lines down.

 

[Leinhit]

first of all speaking of others who advised me and my own personal experience you should only use a factory OEM sensor when replacing them on jeeps.

I replaced a TPS sensor this summer with a fairly expensive aftermarket and then spent the next 30 days chasing problems that didn't exist because I couldn't accept that he brand new sensor would be bad. following advice here I replaced it with a factory OEM and it ran perfect and has ever since.

you replace the factory sensor for a reason just replace it with a factory OEM get it from Amazon and you can probably return it if it wasn't the problem.

after my experience and that of others I read I would never replace with anything but factory OEM sensor otherwise you will just never truly trust it completely.

 

[John Scoggins]

Have you check the engine harness for damage along with making sure the grounds are good and clean, espically the ground strap from the engine to firewall.

 

[HellionTJ]

I have oem sensors on order, should be here tomorrow. Definitely going to be doing all that is suggested by all of you! Thanks a lot guys! Tonight I’ll do a smoke test in the vacuum system, check the coil, maybe change the spark plugs while I’m in there, and check the harnesses

 

[WWII Jeeper]

Here are a few pics for you.
Keep in mind, my Jeep is an 06 TJ X, so the part numbers may not be the same.

The vacuum reservoir is under the battery tray. Remove the battery, remove the bolts for the tray and lift out. I had an issue with the vac hoses that come off the intake manifold.

They are kind of hidden, but if you reach just under the throttle body, you will be able to tell how many you have. With the engine heat, my hoses had slight cracks, just enough to cause a leak.
Hope this helps
Ray

 

[someguysjeep]

yah that's it just a small black box under the battery tray. kind of a PITA to get to. IIRC the screw that holds it is visible from the wheel well.

 

[AndyG]

Definitely do the plugs and be careful about the type of plug and that you gap them just right.

Put in the correct sensors and make sure the gas cap isn't loose and check the vacuum lines.... Especially everything involved with the purge circuit... Hopefully you don't have to get into it behind the right rear tire but I wouldn't lose any sleep over it it typically isn't performance-related first get the thing running right and then chase that code last unless it seems that is affecting performance.

Thank you for coming to the forum, you will find a lot of great people here that are very knowledgeable... And then you will find me.

Also on behalf of the TJ Forum, we forgive all Canadians for Justin Bieber. Don't blame yourselves.

 

[HellionTJ]

So I have an update...

checked the vacuum system and I don’t seem to have any leaks, and I didn’t fix the vacuum line to the canister under the passenger fender. Found out that the crank sensor wasn’t seated down all the way. Seated it properly and it ran great, no codes other then the evap code and the TCC solenoid. It ran great for a day, the all of a sudden today on the highway the CEL started flashing and it ran like crap. Check the codes and I’m getting 3 cylinder misfired and 3 cylinder codes for the coil.. but NO codes for crank or cam sensors... think it’s the after market crank sensor? My new sensors are delayed until Tuesday now... also think the TCC solenoid isbad cause the trans won’t shift into OD...

 

[AndyG]

So I have an update...

checked the vacuum system and I don’t seem to have any leaks, and I didn’t fix the vacuum line to the canister under the passenger fender. Found out that the crank sensor wasn’t seated down all the way. Seated it properly and it ran great, no codes other then the evap code and the TCC solenoid. It ran great for a day, the all of a sudden today on the highway the CEL started flashing and it ran like crap. Check the codes and I’m getting 3 cylinder misfired and 3 cylinder codes for the coil.. but NO codes for crank or cam sensors... think it’s the after market crank sensor? My new sensors are delayed until Tuesday now... also think the TCC solenoid isbad cause the trans won’t shift into OD...

It's hard to rely on aftermarket sensors for these... It sounds to me like you are on the right track and somewhere between the sensors in the ignition you're probably going to get it dialed in.

a bad coil pack is always a possibility also

 

[HellionTJ]

It's hard to rely on aftermarket sensors for these... It sounds to me like you are on the right track and somewhere between the sensors in the ignition you're probably going to get it dialed in.

a bad coil pack is always a possibility also

definitly going to have to look at it tomorrow.. I’ll do the coil test Chris suggested... I hate that my sensors were delayed.. I have a feeling that I’m chasing my tail with the after market one.. maybe worth putting the other crank sensor in it to see that happens.. I’ll put a few layers of tape on it so that I get the spacing correct...

 

[AndyG]

definitly going to have to look at it tomorrow.. I’ll do the coil test Chris suggested... I hate that my sensors were delayed.. I have a feeling that I’m chasing my tail with the after market one.. maybe worth putting the other crank sensor in it to see that happens.. I’ll put a few layers of tape on it so that I get the spacing correct...

I hate knowing what to do and not having the parts or trying to figure something out while I'm not trusting something... It just messes with your head.

 

[Oldguy]

Coil will act up after they get warm. I always go back to the last thing i did when i have issues

 

[HellionTJ]

changed the plugs today and checked the coil. I’m getting barely any spark from the coil.. you can barely see it sparking the spark plugs... I’m thinking this thing needs a coil too now.. still no codes for crank or cam sensor tho... just misfires and multiple missfires now...