Only 2900 miles and I think I have a fuel pressure leak down issue

[Dummy SALAPA]

The other morning I jumped in, started the Jeep and the starter kept cranking the engine and and it would not start so I hit the start button again to turn it off, hit it once more to start it again and it started right up. My driveway is on a slight slope. I noticed this a few more times over several days and it didnt do it when parked flat and the Start/Stop works perfectly, no issues. Then it started when sitting flat and not just on a cold engine but after sitting over an hour. If I push the start button to ON and let the fuel pump prime, it will start without issues every time. I have no noticeable fuel leaks best I can tell, however I was reading that there is a check valve that could go bad. I only have 2900 miles on this brand new rig. I have it scheduled for the Dealer next week. Anyone else have this so early in the game?

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[Bandit’s Lair]

Not on this one but Jeeps are notorious for having fuel pump issues in the past. I’ve changed a couple in my time. It’s a slight PiTA but not that difficult. With that low of milage just hand it over to the stealership and let them deal with it.

 

[SoK66]

Since new my ‘23 JT with 18k miles did this once. I hit the start button and it started to run on maybe two cylinders. As a former tech I knew it was low fuel pressure so out of curiosity I let it keep going. Gradually one cylinder at a time fired up. I presume the residual pressure valve in the fuel pump got held open and it had to build pressure, then one at a time bleed the injectors. That was six+ months ago and it has never done it again.

 

[S JEEPN]

A million parts made you must be lucky to get the bad one in a million if that is it. Had a TJ do that would turn the ignition on and off a few cycles to let it prime after discovering the problem waiting for the pump to be delivered from Mopar parts. The TJ had the regulator on top that sent the extra fuel back into the tank it had good pressure once primed to the fuel rail just bled back down after sitting too long.

 

[ShadowsPapa]

Totally strange as even the old 4.0 the pump runs for roughly 1 second and has pressure built up.
It doesn't really matter if pressure leaks down - sounds like you've got fuel totally leaking back.
Most will drop to no pressure with time. With those where you can hear the pump, you have to listen VERY carefully during the start process because the pump runs such a short time, you'll miss it. What I'm saying with all of that is - it takes but 1 second to build pressure. And I'm talking a vehicle where the pump is the entire length of the car behind the fuel rail.
If it acts like being described here by folks - there's some problems going on...........

This tiny pump here, sitting in the tank at the very back end of the car runs such a short time and has pressure in the rail within a second or so. And that's after swapping injectors.

 

[Dummy SALAPA]

I have it scheduled for this coming Friday at the dealership. I'll let you know what they find.

 

[S JEEPN]

I have it scheduled for this coming Friday at the dealership. I'll let you know what they find.

Hopefully it is just the common issue of a sensor, module or something like that to make it a quick diagnosis and repair.

 

[Lost1wing]

I have it scheduled for this coming Friday at the dealership. I'll let you know what they find.

Good luck with the dealership putting your Jeep on a slight slope and letting it sit overnight. If it doesn't repeat the problem sitting level, they most likely will shrug it off and blame it on something you will have to pay for ( fuel filter). You can try something yourself. When you have it parked in a position that you know it will fail, don't start it. Without depressing the brake, turn the ignition on. Turn it off, and turn the ignition on again. On the third ignition cycle, depress the brake for a normal start. If it was a fuel pump or a fuel pressure regulator problem, it would probably start normal. If it still shows the issue, I think your problem is somewhere else.

Can't wait to hear what the dealership says.

 

[Dummy SALAPA]

The dealer looked at it this morning and found a bad fuel pump. They have to order one so it will take 5 days or so. I went back and picked up my Jeep and will bring it back when the part comes in.

 

[ShadowsPapa]

The dealer looked at it this morning and found a bad fuel pump. They have to order one so it will take 5 days or so. I went back and picked up my Jeep and will bring it back when the part comes in.

No surprise............. it makes total sense. Fuel pressure dropping and taking time to reload the lines and build pressure.
Electric pumps are very different animals from others. Pushers, not pullers like mechanical pumps.

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