No-start issue (see inside for details)

JeepRehab

JeepRehab

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OK, so I've tried searching far and wide with mixed results. Here's the story.

Jeep: 2006 TJ/LJ (Unlimited) so it's got a 4.0 I6. 134k miles.

Yesterday I replaced entire cooling system courtesy of Chris' delicious write up and youtube links. Replaced as I was on the stock hardware and started to have coolant boiling on long drives with weeping from waterpump.
- Replaced radiator with OEM, upper and lower hoses, thermostat, fan clutch and waterpump. All went to plan, ran the Jeep after the replacement, no issues, no leaks, had a CEL for the ECT sensor, but it was because I forgot to plug it back in. CEL cleared after a couple drive cycles but is still there if you do the ignition trick to read codes.

Today, I go to drive the Jeep a longer distance to visit family (approx 40 miles, 75% highway) as a bigger test for the cooling. Made one stop at gas station for water and came back, seemed to have a bit of a hard time turning over, but fired up and drove the rest of the way without issues. No issues driving at all with power etc. Stopped, saw family, came back out and the Jeep cranked, turned over and then got a really rough idle, dropped RPMs then died. Let it sit about 15-20 min, then it just cranks but won't turn over at all.

From what I've read, most threads point to Crank Position sensor, but trying not to get tunnel vision and looking to you guys for help.
I actually have a crankshaft position sensor that I bought prophylactically, so no issue to switch it out, I just can't seem to find the damn thing despite looking through countless threads, some pointing to drivers side trans bell housing others pointing to passenger side.

Other pertinent History:
- No codes other than ECT sensor, with ignition code-check trick, but CEL comes on with key in ignition and went away after starting (when it started today).
- Gauge cluster works fine, so thinking maybe not PCM related?
- It had a bit of a rough idle regardless of ambient temperature, driving time etc. never dropped revs, just felt rough, but ran smooth as butter otherwise.
- Since I bought the Jeep, it's always took about 3-4 seconds to turn over after sitting for a day or two (it's my second vehicle). But it's never not started.
- Battery has power; tried to jump it just for the sake of it and same symptoms as above.
- Oil and coolant look clean; just changed oil and flushed coolant with cooling system refresh. 6 qts of Castrol 10w-30 and Zerex G-05 HOAT coolant mixed with distilled water and passed the coolant tester. Also changed trans fluid with Red Line MTL 75W-80.
- Serpentine belt looks good.
- No weird sounds from the engine on crank, seems to want to turn over but just can't.
- To my knowledge it's an OEM fuel pump; I can't really tell if it's running or not, but haven't had any sluggishness performance-wise, or heard any whine from it.
- I did spill some oil when refilling near the fuel rail, but immediately "mopped" it up with a rag, but can look into it further, didn't look like it got into anything important.
- Had the Jeep towed home, so it's in the parking spot ready for some TLC, but would have to have it towed to get to a shop, would prefer to do-it-myself if possible. I don't have a pressure tester to check that the fuel system is getting pressure or a multimeter to check voltages, but can get one if needed.

Hopefully I added enough detail, I'm going to scour my storage unit for that Crank position sensor. Any help is greatly appreciated!
 
Sounds like fuel is a good place to start. After checking all fuses inside and out and making sure it has gas in it I'd cycle the key and listen for the fuel pump. If you hear the pump then look into a fuel pressure gauge or at least open a line somewhere to make sure there is pressure in the fuel line. It really does sound a bit like the pump failed. That's where I'd start. It could be some sort of ignition problem but you'd probably get a code or at least get it to start.
 
pagrey said:
Sounds like fuel is a good place to start. After checking all fuses inside and out and making sure it has gas in it I'd cycle the key and listen for the fuel pump. If you hear the pump then look into a fuel pressure gauge or at least open a line somewhere to make sure there is pressure in the fuel line. It really does sound a bit like the pump failed. That's where I'd start. It could be some sort of ignition problem but you'd probably get a code or at least get it to start.
Click to expand...

Thanks for the reply! Gas tank is 3/4 full, just got Shell 87 yesterday.

Just to confirm, if I hear the pump when cycling the key then I should check the pressure to assure it's got enough, if I don't hear fuel pump, just get a new one and replace it? I'll be sure to check all fuses as well.

Just found the crank position sensor, so at least I'll have that in the case that the fuel "workup" proves unfruitful.
 
If you don't hear the pump you need to make sure it has power. That's checking the fuse and relay along with testing for voltage at the tank when the key is cycled. Good to hear you have gas, more than once... Nothing wrong with doing that sensor, sounds like a good idea.
 
Update:
Fuse and relay for fuel pump looked fine.

I think I found the Crankshaft position sensor, but can't seem to trace it's wiring harness to it's origin.

I can't really tell if the fuel pump is priming as I don't hear it while sitting in the vehicle, but I don't have a buddy at the moment to help me out with cycling the key so I can listen from the rear end. So I'll check back on that one.

Here's a pick of the sensor; it's on the passenger side of the trans bell housing (it's an NSG370 6Speed manual).
CKP Sensor.jpg
 
OK, final update from me for the night. It's not the Crank position sensor, it was super easy to replace, just had to pull the plug, I was going off the DIY's for the earlier models and thinking I had to trace the harness back and disconnect it elsewhere, then looked at the replacement sensor and DUH!

Regardless, I was searching the forums and encountered another post by Chris with a similar issue and he had issues with his fuel level sensor. I know mine has to be sticking as I have the "overflow" issue when filling up and have had issues where the auto-fill method won't work. That being said, that issue alone steers me more toward fueling issues anyway.

Anyone know anybody in the DMV (DC/MD preferably) area that would be willing to help me check power to the pump etc.? Frankly that stuff is out of my wheelhouse.

Also, if anyone has the part # for an 05-06 TJ Bosch fuel pump that would be greatly appreciated. I know the earlier models were discontinued, but read on here that you can still get them for the 05-06? If not, any recommendations on aftermarket?
 
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Here’s what I would do in this order. Check for codes and address as needed. Buy a can of starting fluid. Remove the air intake tube from the throttle body. Have someone crank the engine over while you spray a small amount of starting fluid into the throttle body. If it runs you have a fuel supply issue.
 
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Cycle the fuel pump on-off-on via the ignition switch 12-15 times, keeping it on 2 seconds each each time it's in the on position during the cycling. Then try starting it and let us know what happens.
 
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Jerry Bransford said:
Cycle the fuel pump on-off-on via the ignition switch 12-15 times, keeping it on 2 seconds each each time it's in the on position during the cycling. Then try starting it and let us know what happens.
Click to expand...

So just tried this and same results, cranks but just doesn't start.
- Just to clarify, I was turning the key to the second position (prior to cranking) then letting it sit for 2 seconds, then all the way off, then back on for 2 seconds, repeat x15.
- While I've got your attention Jerry, any info on the fuel pumps for the 05-06?

Of note, my fuel gauge was reading full when key turned in ignition, earlier in the day it was down to 3/4 tank. I know I put 12 gallons in it 2 days ago and have only driven maybe 60 miles, so shouldn't be out of gas. Regardless, I'll try to fill it up and see what happens.

Daryl, I'll also try the starter fluid method once I can get to the autoparts store tomorrow morning and report back.

Thanks for the help guys.
 
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UPDATE (HELP NEEDED):
OK team, so I bit the bullet and had the Jeep towed to a trusted local shop. They diagnosed it as a fuel pump issue, replaced it along with my OPDA (preventative) and fixed a leaky front crank and rear main seal as well as valve cover gasket (all known about prior to this issue).

Long story short, Jeep started right up when I picked it up from the shop, drove it home (approx 47 miles) without issue. Went to start it this morning and same issue as my initial post, cranks but won't start. Needless to say I was close to "blowing a gasket" of my own. But what gives? Same situation as before, Jeep starts and drives runs for 40-50 miles then gives up on me when I try to start it again.

Fuel pump was replaced with OEM (hence the delay in my follow-up post, it took FOREVER to get). Could it be something else sensor related? The work is covered under warranty, but it would be great if it was a simple fix and I could actually drive the friggin Jeep after not having it the past month.

Any help is appreciated.
 
scottgraham said:
Longshot, but it could be your ignition switch going out.
Click to expand...
Appreciate the suggestion. But wouldn't this result in it not trying to turn over at all? Or is this what allows the engine to get spark? If the latter, I'll try to give this a shot tonight.
 
Final Update:
Turns out they didn't reuse my OEM Camshaft position sensor when they replaced the OPDA (just used the Crown Automotive one). Thus ended up not being able to get good timing reads. Threw a code for CPS circuit error which led them to change it back. Fires right up now without issue. Fingers crossed that this is the last thread/post I have to make for a while!
 
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JeepRehab said:
Final Update:
Turns out they didn't reuse my OEM Camshaft position sensor when they replaced the OPDA (just used the Crown Automotive one). Thus ended up not being able to get good timing reads. Threw a code for CPS circuit error which led them to change it back. Fires right up now without issue. Fingers crossed that this is the last thread/post I have to make for a while!
Click to expand...
That always feels good when you get the ah-ha moment.

Good for you and happy wheeling
 
Rubicon88 said:
That always feels good when you get the ah-ha moment.

Good for you and happy wheeling
Click to expand...

thanks! Definitely relieved to not have to be sourcing a PCM (at least for now)! Hopefully since I have the 6 speed, I can avoid having to shell out the $$$ for that.
 
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