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Cranking, no start...

30K views 17 replies 8 participants last post by  jklightner  
#1 ·
Hey guys, I have a crank, no start problem and I have exhausted all search options on here and the rest of the 'nets. Most other similar issues never post back with their solution or their solution hasn't worked for me...

After being on the highway for about an hour with everything working fine, I stopped for gas not far from my house with 1/4 tank left. After pumping was done, Jeep no longer starts. So- a well warmed engine, stopped for maybe 5 minutes. Turns over for forever with no result. If I stomp the gas pedal it will start to try and catch and eventually come to life (at like 3-4k RPM), but it's not firing on all cylinders or misfiring. I can keep it running this way if I hold the RPMs above 1.5k, but it will die if I let off. No codes being thrown via code reader or the "key dance". No unusual behavior with any of the indicator lights.

-Battery Voltage is 12.5ish, stays around 11v while cranking
-Fuel Pump primes/runs when ignition is turned on, I have tried turning ignition on for a few seconds, off, on again, off, then crank to make sure the lines are primed. No way to easily check pressure on the 5.7s :frown2:
-Put in a new Oil Pressure Sensor a few months ago (it threw all the related codes)
-All fuses are good
-New Air filter
-Replaced the Crank Pos. Sensor and was able to get it to start fairly normally, but it still ran really bad- not all cylinders, misfire, or whatever. Every time I started it, it got a little worse, harder to start to where eventually I was back to the original symptoms. This was after 4-5 start and runs. The 2nd start I did drive it a little bit around my cul-de-sac, but the misfire concerned me so I parked it again.
-After this, I unplugged the battery for a few hours to potentially clear anything in any of the computers, no changes. It's been sitting for 3 days now, so any heat or time related things would have sorted out.
-Pulled 2 plugs, they have spark the entire time the engine is cranking.


Other notes- a few months ago, right after the Oil Sensor was replaced I was getting random P0158 codes that would come and go for about a week, O2 Circuit High Voltage, Bank 2 Sensor 2. I never did anything about it because the code went away on it's own and this was...2 months ago? Maybe more?
Over the past year I've had maybe 3 times where the Jeep took a little longer to start than normal, like the fuel pressure check valve hadn't done it's job and the pump was playing catch-up on pressure. But still fired up and ran fine.
I do have a remote starter installed, and have for years. I know it does interact with the CANBUS, I think even in-line with some of the wires, but I don't think this is the culprit since I can get the Jeep to kind-of start and I've installed hundreds of these remote starters and never had them cause issues this long after being installed (they would have screwed stuff up from the very beginning).


I am stumped on this one now, even more so because it was so immediate showing no signs leading to whatever has happened....
 
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#2 ·
I'd guess the problem has to do with the injectors. If you have spark, fuel is usually the problem, and if you can get it to run with the gas held down with misfiring, it definitely sounds like you're not getting enough fuel to the cylinders. The P0158 code can be caused by a faulty injector as well.

You can probe the voltage on each injector while cranking and see if there are any obvious problems with power delivery. Otherwise, use a mechanic's stethoscope or something to listen to each injector for problems.

If the injectors aren't the problem, it could be a sensor. The MAP sensor could be giving a false readout and causing the ECU to cut fuel.
 
#3 · (Edited)
New MAP and Camshaft Pos. Sensors.....no change :|
Edit: I blasted a bunch of starter fluid into the throttle body, Jeep doesn't fire up at all- tried this a few times.
So I'm back to assuming it's a firing issue? I pulled a different plug on the opposite side of the engine as last time- still have a good, strong spark....
 
#4 ·
I misread the diagnosis to a P0158 code; that code actually could imply that your engine is running rich, not lean. If that is the case, spraying starting fluid into the throttle body will flood the engine. This is consistent with what happened.

When you pulled each plug, how did they look? An engine running rich will typically leave the plugs looking black.
 
#5 ·
The plugs looked pretty normal- kinda brownish. Not wet/fuel soaked, not really dark, not white/ashy...
 
#6 ·
So not much of an update, but more info, I guess.
I got the right tool (the tools I already had didn't fit right with the clearance) to disconnect the fuel line from the rail- there is no check valve in the line, so fuel dumped out. It wasn't really pressurized so as to spray everywhere, but there was definitely an ounce or so that poured out. I hooked it up to a translucent catch-can and fuel pumps out for a few seconds when I turn the ignition on and continues to pump out while cranking. This does confirm that I am correctly hearing the fuel pump running- I can't confirm pressure, though. I guess there be a low pressure possibility?
I have noticed that when I let it sit for a while, like a few hours or more, it will fire up almost immediately. It still won't run right, and unless I have a bit of pressure on the gas pedal it will immediately die.

I have completely removed the remote starter, with no change. I did confirm that it doesn't wire in-line with any of the CAN-BUS or key security lines; it just taps in to a few.

My brother works at a dealership for a completely different manufacturer, but he has a lot of testers and tools that will still work for me as well as access to their AllData system that covers every brand. Although he's at the other end of the country, he's going to ship me out a proper fuel pressure tester with the adapters and a few other things so I don't have to waste the money on this expensive stuff that I'll never need again; and that will likely still not give me any answers. He hasn't had a chance to check AllData for info yet because of being out of the shop for a little while---of course the system is set up so he can't log in at a different location than his dealership......



Unfortunately I doesn't seem like I'm getting much help here; but I will continue to report back with anything in case of the (what seems to be very unlikely) event that anyone else has the unfortunate luck that I seem to have.
 
#7 ·
I finally found another situation that sounds exactly like mine- with a not so happy ending...it's an '05 Hemi in a GC, but should be the same, right?
05 5.7 GC cranks but won't start

He had the exact same symptoms, replaced all the same sensors, did the same fuel line into a bottle "test". He even replaced the fuel pump anyways, and said he recently had the ECM replaced (something I was starting to think about), plugs, and new throttle body. No codes, plugs sparked, injectors ticked, everything said everything should work.
He gave in and took it to a shop- turned out to be a bad radiator cap that allowed the temp sensor to read wrong and over-heat his motor with no indication, warping the heads leading to compression loss in a cylinder in each bank. So he got a re-maned engine put in....
I think I had the coolant flushed back in February, (I'm at work so I can't check my records to confirm). I would assume any issues like this would have been caught by the shop?
I did a long (~1k miles) road trip towing a 22' trailer soon after, and the weather here has been heating up.....so I would not be surprised if this has happened to me. I noticed the overflow bottle is sitting either at (or below) the low fill mark. My hour drive home right before this was in typical Bay Area traffic coming out of San Francisco, prime for head warping with me being ignorant to any of it.

I'll be getting a compression tester with the stuff my brother is sending me, so I'll be able to figure this out.
 
#8 ·
When you replaced the oil pressure sensor did you replace it with an OEM Mopar sensor?? I ask this because I replaced my sensor with an aftermarket sensor when mine failed and no OEM part was available. The aftermarket sensor only lasted about three weeks before it failed and could not start. I replaced with an OEM Mopar sensor and everything has been fine since, about two years now.

Dan
 
#9 ·
I did not use an OEM Mopar. I did read about the reliability of non-oem oil pressure sensors, but none that led to a no-start with no codes- just failing and throwing the same codes again. So, yes I took that risk, but I figured if my aftermarket sensor failed then I'd just get another set of codes- P0520 & P1521.
Also- considering I drove it a few times before getting around to replacing the sensor, knowing that I didn't ACTUALLY have oil pressure issues and it still ran/started fine (without MDS working)...
How were you able to trace a no start issue back to this sensor? Did you get any codes?
 
#10 ·
Well....story time. Hopefully someone can catch something in all the steps I took today...



Started this morning out with a compression tester and a noid light set.
Noid light was easiest so I started with that, checking all the injector circuits. All of them working fine.
Then I proceeded to pull all the coils and 1 plug from each cylinder. While pulling the passenger side, I noticed the ground strap to the body was really corroded at the bolt where it attaches to the body, without much pressure from me testing it, it separated entirely and fell down somewhere behind the heater core hoses. OKAY, well, it's something; but I still want to progress with checking compression. So I left that and moved on.
I noticed every plug I pulled was still wet with fuel due to turning the engine over a few times while checking every injector circuit. I did NOT disconnect anything besides the 1 injector I was testing each time- so I SHOULD have had spark igniting the fuel that was soaking these plugs......I think back to that grounding strap. Again, I still want to check compression. When I checked for spark a few days ago, I was grounding each plug with a test lead to somewhere on the engine block each time- a bolt on the water pump or some where similar.

Compression kit is no good to me, because the socket needed to screw the adapter into the cylinder is too large for the opening in the valve covers, and even though the hose on the kit is also the right thread pattern, I cannot get the hose to thread far enough in to get a good reading- hose twist/flex. I need a kit with a longer, ridged line that screws into the cylinder....great.
Well, lets go back and see what this grounding strap can change. I put all the passenger side plugs back in, put their coils back in and hand-tighten the coil screws. Without doing anything with the ground strap, I decide to attempt to start the engine. It fires right up, immediately and runs about how you'd expect with all (4) driver cylinders open and all the intake open up to the throttle body. But it's running and idling....the idle is surging, but this seems like progress. Maybe the ground strap grounded somewhere when it fell...?
Back under the hood I put a new connector on the ground strap and bolt it back up, start the engine again- still running the same on 4 cylinders.
At this time, since I have all the coils and half the plugs out---I might as well put new plugs in. At 113k, they are probably over due anyways.
Back with new plugs, I swap out all the passenger side plugs- crank engine, same result....great, I guess.
Now, the driver side. However, unless the ground strap worked some magic....I technically haven't FIXED anything yet. Why is is constantly firing immediately and running somewhat decently off only half the engine.

Driver side, I start at the back cylinder, all other plugs are still out- new plugs in, coil on, start the engine. Runs and starts pretty much the same.
As I work my way up to the front cylinder, starting after each cylinder is done; I noticed it's getting a little harder to start, but ultimately the same result with a surging idle, but I don't need to give it any gas.

Final cylinder done--- original issue is back. constant crank, a few chugs, no start. give it gas, eventual start and run really bad with no idle.
Okay....lets work backwards. Unplug Cylinder 1 coil, no change. Pull the coil and 1 plug, no change.
I do a few different combinations of this on the driver's side half with no real changes. I end up with all plugs in, all coils on, BUT all 4 driver's coils unplugged....engine fires right up and runs like before. Now I'm throwing lots of codes, all relating to driver's side cylinders, as to be expected--- Multiple Cylinder Misfire, High Airflow/Vacuum Leak and Secondary Circuit Insufficient Ionization for coils 7, 5, 3, & 1. (P0300, P2172, P2320, P2314, P2308, P2302). Oddly...only 1 specific cylinder misfire code, P0305 for Cylinder 5- but only when I have the coil unplugged. I have been noting and clearing codes after each attempt to better track what it's reading.

Since it's just me trying everything and I can't see or do any active testing under the hood while cranking or putting pressure on the gas pedal- makes it hard to do much more troubleshooting.
Putting a small wedge to crack the throttle body butterfly valve open (thinking back to cable controlled throttles vs. this electronic deal) allows the engine to start up fairly normally, obviously screwing with a lot of other systems and sensors...but it can idle on all 8 cylinders now, even after I pull the wedge out. Throttle has almost no response, but I figure the ECU has gone into some sort of a closed loop. The idle isn't smooth either, no surging, but something isn't right.
At this point.....my brain is fried for the day and I have to get ready for an event I have to attend tonight. This all turned into more of an info gathering once I started getting some weird results.


So- all injector circuits are good, fuel is wetting plugs, new plugs installed, partial engine is starting and running under certain circumstances...still don't have compression information....
If I had 1 or 2 misfire issues, the fact it runs fine off only half the engine says that I should still get a fairly normal start situation with all 8 cylinders?
Could compression still play a part in this? I have only tested spark on plugs from cylinders 2 and 3.
 
#11 · (Edited)
Pulled driver side valve cover, found a loose intake rocker on cylinder 5. Valve isn't closing all the way. Doesn't seem to be the common problem of a failed lifter that destroys the cam and the spring doesn't look broken.

Finally got a compression tester that'll work, 0psi on cylinder 5, matches the stuck valve. All other cylinders read a constant 140psi.
Yanked the intake off, looks like a dropped valve seat.
Rocker picture you can see the gap between the top of the valve and the rocker arm. Hard to see at the angle, but comparing to the spring behind it, it is still compressed some.
And the best picture I could get of the valve.


Looks like be pulling the head and looking into a rebuild.
Yes, I've been using 87 octane for the few years I've had it...wish I'd known better before. Always changed oil with Full Syn when it was time, always made sure it was the right weight for the MDS.
 

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#12 ·
Pulled driver side valve cover, found a loose intake rocker on cylinder 5. Valve isn't closing all the way. Doesn't seem to be the common problem of a failed lifter that destroys the cam and the spring doesn't look broken.

Finally got a compression tester that'll work, 0psi on cylinder 5, matches the stuck valve. All other cylinders read a constant 140psi.
Yanked the intake off, looks like a dropped valve seat.
Rocker picture you can see the gap between the top of the valve and the rocker arm. Hard to see at the angle, but comparing to the spring behind it, it is still compressed some.
And the best picture I could get of the valve.


Looks like be pulling the head and looking into a rebuild.
Yes, I've been using 87 octane for the few years I've had it...wish I'd known better before. Always changed oil with Full Syn when it was time, always made sure it was the right weight for the MDS.
Sorry to hear that @Wombler, dropped valve seats is one of the known & well documented flaws of the Hemi, particularly in the '06 & '07 model years.
 
#13 ·
As Big Blue mentioned, valve seat drops are extremely common on the early Hemis. The general consensus is that the cause for a dropped valve seat is an overheat at some point. The overheating, whether minor or major, causes the valve seat to warp and then it's just a matter of time until one fails.

There's really nothing you can do to prevent it, and since I assume you bought it used, I'd bet that nothing you did caused the problem.
 
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#14 ·
I feel your pain man. I went through this 2 years ago. Catastrophic engine failure at 116k due to dropped valve seat. Check out HemiPro out of NC for a solid rebuild.
 
#15 ·
12/07/22 2006 Jeep Commander start and no start but will crank over, open the hood and there's two fuse boxes on the drivers side, have somebody keep slapping the top of the one closest to your battery while turning the engine over and it will start and stay running. The problem is the little square brain mounted on the front of the fuse box between your battery and the fuse box with two plugs on the bottom of it. It took me forever to figure this issue out (common problem). To replace the brain the cost is roughly $800.00 (do not buy used or remanufactured). Keep in mind a few slaps while turning the engine over will always get you running again and in some cases will last for a long time until it happens again. Time for another slap.
 
#16 ·
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