07 wrangler, stalling at idle/traffic lights.

[Joesmith]

My 07 wrangler X will randomly shut off at a red light.
if I keep the RPMs up I think it prevents this, but I’m not sure.
and sometimes it randomly will not start in the mornings (after sitting. Time of day seems irrelevant) it just clicks, but if I put it in neutral and move it just a bit, try the key again and it will start.

When it shuts off it doesn’t sputter or anything just quits. No warning.

I have had it throw a miss fire in random cylinders a few months back, I changed the plugs, wires, coil pack, and cam shaft position sensor (it threw a code for that too)

any thoughts?

 

[superj]

dirty crank position sensor?


i have no idea but just thinking since you said holding hte rpms up might keep it form dying, maybe its a dirty something? throttle position sensor, crank sensor, something like that?

 

[Andrew Mac]

Run a can of Sea Foam through it with the fuel. I've had great success with the same issue!

 

[Andrew Mac]

As for the sometimes not starting, then positioning to neutral and it will start. There is a position sensor that can be adjusted, sounds like that may be the issue???

 

[mikeswillys]

I second using sea foam. I use a can every 1k miles in all my vehicles my jeep almost has 100k miles and the spark plugs outlasted the rocker arms.


Sent from my iPhone using Jeepz.com mobile app

 

[JPNinPA]

The stalling at a light can be a few things. Start easy. Clean your Throttle Body and the IAC. and the TB.
Blow out yhe (TPS) trottle position sensor or at least work the butterfly valve 20-30 times full open to close. Then verify good connections to the TPS and IAC. This should be done every 30k miles with plug changes.


What rpm do you idle at when you start and once at temp? Is it 1000tpm or higher?

The no start issue could be similar or different. When you turn the key do you hear the fuel pump? From a cold start if you just turn the key and the engine turns but no start then. Immediately try again and it starts it could be the fuel pump. Next start turn the key on listen for the fuel pump to start and stop. Then key off and back on. Count 3 then start. If it starts up the check valve in the fuel pump is shot. Common issue and is a part of the pump. At this point do a fuel pressure test.

Crank sensors fail without warning. Sometimes they shut the engine off mid running. But it is not only when at a stop.

If you replace any sensor use OEM only. Jeeps are finicky and some brands are bad out of the box.



Never look down on anyone unless you are helping them up - Jesse Jackson

 

[JPNinPA]

I second using sea foam. I use a can every 1k miles in all my vehicles my jeep almost has 100k miles and the spark plugs outlasted the rocker arms.


Sent from my iPhone using Jeepz.com mobile app

That is a lot of seafoam.
Every oil change is good.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[Joesmith]

The stalling at a light can be a few things. Start easy. Clean your Throttle Body and the IAC. and the TB.
Blow out yhe (TPS) trottle position sensor or at least work the butterfly valve 20-30 times full open to close. Then verify good connections to the TPS and IAC. This should be done every 30k miles with plug changes.


What rpm do you idle at when you start and once at temp? Is it 1000tpm or higher?

The no start issue could be similar or different. When you turn the key do you hear the fuel pump? From a cold start if you just turn the key and the engine turns but no start then. Immediately try again and it starts it could be the fuel pump. Next start turn the key on listen for the fuel pump to start and stop. Then key off and back on. Count 3 then start. If it starts up the check valve in the fuel pump is shot. Common issue and is a part of the pump. At this point do a fuel pressure test.

Crank sensors fail without warning. Sometimes they shut the engine off mid running. But it is not only when at a stop.

If you replace any sensor use OEM only. Jeeps are finicky and some brands are bad out of the box.



Never look down on anyone unless you are helping them up - Jesse Jackson

it idles a little lower than 1000 when sitting at a red light.
the not starting, the engine doesn’t even crank, it just click and nothing.
I’m pretty sure I hear the fuel pump kick on but I’ll check again next time it does it.
it’s just weird that if I put it in neutral, it will start after it fails to start in park.
im dreading chancing the crank shaft sensor as the swear factor is pretty high. It’s hard to reach my big fat guy hands in to those small spaces

I’ll try the sea foam thing, and giving all those parts a once over.
thanks y’all

 

[TerryMason]

It sounds electrical to me. I would start by cleaning the battery terminals if they need it, and verifying the main ground looks good. From there I would wiggle the wires while the engine is running, hoping to find a bad wire.

Having said that...

it’s just weird that if I put it in neutral, it will start after it fails to start in park.

Perhaps a faulty neutral safety switch.

 

[JPNinPA]

Agree with The NSS issue after reading it only clicks when starting in park.

Could try this to verify. Dangerous!!! Needs to be in park
Neutral Safety Switch Work Around - YouTube
Never look down on anyone unless you are helping them up - Jesse Jackson