Code P0303, running rough, no black smoke

Gabe Watt · **Posted:** Mon Jan 19, 2015 12:07 pm

2005 CRD, 145k miles on it, a few mods (listed in my signature).

Heading the store today I get on it a little before it's fully warmed (let it warm for 2-3min after I started it), starts running rough so I pull the codes when I get to the store and it shows P0303, misfire cylinder 3. No black smoke, and the rough running isn't consistent. Am I looking at rocker failure, bad injector? It's got a full tank of good fuel in it.

flash7210 · **Posted:** Mon Jan 19, 2015 3:02 pm

Might just be a air in fuel problem.

Gabe Watt · **Posted:** Mon Jan 19, 2015 11:05 pm

flash7210 wrote:

Might just be a air in fuel problem.

That was my first thought, but my fuel pump is working, and the plunger was hard when the Jeep was running. So I'm thinking it's not air in fuel related, especially since it gave a cylinder specific DTC.

flash7210 · **Posted:** Tue Jan 20, 2015 12:52 am

I have been going through pretty much the same problem as you.
Engine would randomly sputter and stall for no apparent reason.
And I have been using a facet lift pump mounted in the engine bay.

I would occasionally get a p0302 code but not every time.

Though maybe it was the facet pump so I remove it.
Didn't make much difference with the stalling and when I would check the primer there was air in it.
So with or without the facet air is getting into the fuel lines from somewhere.

I also checked all four injector plugs. Unplugged and checked each connection and made sure they were fully connected.

Drove 300 miles today with no hard starts and no sputtering or stalling.
So we will see if this problem continues.

Gabe Watt · **Posted:** Fri Jan 23, 2015 9:57 pm

Shot this video tonight so you can hear what it sounds like, and it sounds bad to me. Anyone have any guesses? This isn't my daily driver, and this noise and rough running aren't consistent.

Gabe Watt · **Posted:** Sun Mar 08, 2015 2:43 pm

The jeep is still having this issue. I thought it was a bad fuel injector, so I swapped the #3 injector for a spare good one that I had, and it didn't change anything. I got close with the CRD while it was running to see if I could pinpoint where the noise is coming from, and now I'm wondering if I have an exhaust leak/issue. The noise seems to be coming from the passenger side of the engine, and sometimes the noise/power loss will subside and the jeep will run normal. Has anyone ever heard of developing an exhaust issue after getting on the throttle too hard before it's fully warmed up?

For whatever reason photobucket isn't letting me share any of the videos I'm uploading so you can't hear the noise. But once I get a proper video uploaded I'd love to hear some feed back from you guys.

flman · **Posted:** Sun Mar 08, 2015 5:16 pm

Apparently this guy has the same exact problem?

viewtopic.php?f=5&t=81426&p=860046#p860046

Mountainman · **Posted:** Sun Mar 08, 2015 5:38 pm

hmm, sounds like it. Maybe those wires are getting pinched at the same spot? I would clean the contacts on both ends of plug/injector. Contact cleaner or the right alcohol (93%?) with the right stiff bristled tiny paint brush until all shiny. And I'd eliminate the supply quick connect at the fuel tank.

flman · **Posted:** Mon Mar 09, 2015 7:57 am

I do not clean connectors, just put on some Deoxit and plug it back in.

papaindigo · **Posted:** Mon Mar 09, 2015 8:44 am

Air gets into the fuel system either at the quick disconnects back by the fuel tank or at the filter head. An in tank fuel pump will pressurize the fuel system all the way to the filter head and "may" force the quick disconnect fittings to seal properly in which case any potential air leaks at the filter head are likely to turn into fuel leaking out at those points. A Facet or other similar fuel pump installed in line a) back near the fuel tank will pressurize the filter head but won't "solve" actual air leaks, if present, at the quick disconnect fittings and b) in the engine bay won't "solve" air leaks at disconnects or filter head, however, if air leaks are minor an inline pump will pressurize fuel at the CP3 inlet and help minimize air in fuel problems. If you use an inline pump ideally you would install it between the tank and the filter head AND drop the tank and replace the disconnects with a bit of marine grade diesel rated fuel line and clamps (no need to replace return line disconnects).

Regardless of the above if you suspect air in fuel primer pump firmness notwithstanding a simple check is to add a) a bit of clear vinyl hose in the outflow from the filter head to CP3 and watch flow at idle for a bit or b) add a clear inline filter in the same location. No bubbles excellent; few bubbles not so good; lots of bubbles bad.

Gabe Watt · **Posted:** Thu Mar 12, 2015 4:44 pm

I don't think it's air, and after talking to geordi and emailing him a video, he thinks it's a rod cap coming off. That is not what I wanted to hear, but the truth can hurt sometimes.

anyhow, here's a video of my CRD running, terribly. Any other ideas as to what it might be?

https://vimeo.com/122037434

Code P0303, running rough, no black smoke

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