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Tsepz 02-03-2014 12:38 PM

4.0 Limited engine cutting out
Hi guys

Last night my WJ took a few turns of the ignition to start, had to eventually press down on the accelerator to get it to start up.

Today the same happened, but the moment I let go of the accelerator the car cut out, I started it up around 12 times, each time the car cut out immediately after letting the accelerator go, eventually it stayed on long enough for me to shift it to Reverse to get out the driveway.
I then got on the road and the issue persisted, it would idle for a second at a traffic light if I let the accel. go then it would got quiet and then cut out , I had to keep the accelerator in a bit plus brakes at the traffic lights, my WJ felt like a damn hoopty :( the battery seems fine BTW, when the car cut out the electronics stayed on and the battery sat at 14, so I've ruled out that being the issue, and I'm assuming it's the fuel pump. I've had to borrow a family members car for now, a Volvo C70 T5, great sports car, but with rain and gigantic potholes we have here right now, my Jeep is the perfect car, my dad and I are wondering if we should just sell the WJ and get me a new small car as the issues are now coming in one after the other.

What do you guys think is the problem with my WJ? Could it be the fuel pump?

Frango100 02-03-2014 04:09 PM

Re: 4.0 Limited engine cutting out
Could be the fuel pump, but also something else. Once you where driving was it ok? If yes, i would rule out the pump for now. Did you try the keydance to see if any fault popped up? Ignition switch off/run for three times and leave in run at the third time. The odometer will show Done when all ok, or any fault code(s).
This could easily be a problem with the crank sensor or eventually the idle air control stepper motor. Check the faults first and let us know.

lstowell 02-03-2014 05:30 PM

Re: 4.0 Limited engine cutting out
Also check for a vacuum leak. Pressing the gas when starting might richen it up enough to allow it to start, but not enough to idle OR it may be opening the throttle plate enough to allow more air to flow leaning out a slightly rich mixture from a leaking/dirty/jammed injector.

Filthy throttle body sensors, old/fouled plugs/wires, can all make the 4.0 act up. The fuel pressure regulator may be having a bad day.

Unfortunately there are a lot of problems that could cause your symptom and not all of them would leave a fault code.

If you have a local "jeep whisperer" have them listen to the engine, as most mechanics could spot a lean mixture due to vacuum leak or rich due to injector by sound.

Tsepz 02-04-2014 02:51 AM

Re: 4.0 Limited engine cutting out
Thanks for the replies guys!


Once I got going it was fine, only when I have to stop does it begin cutting out, so driving on a highway for example would be fine.
Nope, haven't tried the key dance, I was so late for class I forgot to give that a go, will try it todayfor sure, thanks a lot! :)


Indeed, I'm not going to rule out any of those as they seem to be high possibilities, I do have a place where I take the WJ for regular services, the guys there are 4x4 experts, they primarily work on Jeep ,Land Rovers, Toyota Land Cruisers and Hummers, they have multiple WJs at any given time in their workshop, and have never let me down, I'm going to get AA to tow my WJ there later this week. Thanks a mill :)

Even though I can't fix the issue myself, it's always good to have an idea of what the issue could be so thanks a lot guys :)

Tsepz 02-04-2014 07:35 AM

Re: 4.0 Limited engine cutting out
Went back to go check on my car, and did the key dance, it just said Done.

I may have been wrong to throw out the battery or alternator being dead though, when I Unlocked the car the driver seat sounded very weak as it moved to the memory position that I set it to move to, and then when I tried to start the car it made that loud tapping noise, seems the battery is going after all, between that and maybe the alternator needing replacement, either way I'm taking it in for check up as my brakes need to be replaced to, may as well do it all now.

Frango100 02-04-2014 09:01 AM

Re: 4.0 Limited engine cutting out
A bad alternator could indeed be your problem as well. If you have an universal meter you could check the battery voltage with engine off first. A fully charged battery has 12.7 V (after half an hour engine off). 12.2 V is almost fully discharged. With engine running it should go to 13.5-14.5 V.
If you have a battery charger you could charge the battery first and then disconnect the cable from the alternator (isolate the cable end with tape to prevent making a short). If the engine now idles without problems, then you are sure that the problem is the alternator. Could still be that the battery is bad and not holding a charge for a longer time.

Tsepz 02-13-2014 09:13 AM

Re: 4.0 Limited engine cutting out

The battery and spark plugs needed replacing, but mainly the battery. Took it in, they did a general service (spark plugs, oil, air filter etc...) and they got me a new Bosch battery, my WJ is running beautifully again. Even my brakes were fine, turns out they squeak due to dust, which makes sense as the area I live in has a lot of construction happening, they are repairing the road and building a new gated suburb as well, so my brakes are not liking it, as I do park my car outside a lot.

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