I'm having a fuel problem. I have an early 2004 305/555 engine with 159,000 miles. I was towing across Texas two weeks ago and noticed the truck starting to smoke at idle. By the time I got into Florida it would haze up around the truck from the tail pipe.

I started the truck up the next morning and pulled it in the driveway. It ran smoothly with no smoke. I swapped out the injectors with a set of brand new Bosch Exergy 100hp injectors. I restarted the truck and it wasn't running on all cylinders.

The next day I removed and re-installed all 6 injectors and got the same results.

I sought professional help at the local Dodge dealer. I don't have many options in Miami, FL. They confirmed I was only running on 4 cylinders. They put in 2 different new Bosch Exergy 100hp injectors. They restarted the truck and it ran on 5 cylinders. They re-torqued the "bad cylinder" and got it to run on all 6.

During diagnostics they did a compression test and the truck passed. They indicated that it was bad injectors. I just got a message from Exergy and the 2 injectors I returned were tested to work.

The truck now runs but it does have a surge and an occasional stumble. When it does run smoothly, it's really impressive. I'm running out of ideas and I'm really looking for some suggestions. I'm not confident in the local dealer to fix this issue. I'm starting to get frustrated.

Any ideas?

 

Check the hard lines from the rail, make sure there are no cracks, chaffing, holes, and that the b-nuts are torqued. If those are okay, check your fuel pressure from the CP3, your pump might be starting to go out. Check your fuel filter and fuel lift pump, check the entire system for any leaks.

JMHO

 

Sounds like you have a bad injector harness that is built into the rocker box gasket. Next thing I would do is replace that.

 

I looked for a cracked/loose fuel line but they all look good. My low pressure fuel gauge at my filter reads zero. Might be that my walbro fuel pump is tired. Rain kept me from looking further.

 

Upon further inspection of my zero fuel pressure at the filter, I noticed an electrical connection that wasn't plugged in. The reason why my walbro wasn't working was because the mechanic unplugged it and never plugged it back in. I have no idea how my truck ran without a lift pump. In the past when my lift pump failed, the truck wouldn't run. I'm hoping this will correct any issues I'd been having.

Thanks for all the suggestions/advice!

 

I hope that was the culprit and everything goes back to working like it should. I've been in the aircraft industry for 26 years and we always check for the obvious prior to digging into things and making it expensive.

 

The cp3 can draw fuel on its own, but not near as well as with a good working fuel pump lol.

The stock canister pump, when failed, would not allow fuel to reach the cp3. A walbro, however, will let fuel pass and more than likely is your culprit.

 

I plugged in my walbro pump but it still surges. Doesn't matter if the A/C is on or off. The cruise is on or off. I'm at a loss. There are no leaks that I've found. My mileage isn't great. It's worse than the old injectors with leaky tips. Any other ideas to check out?

 

Ive been having an issue with a stumbling idle, a type of miss, think I have it narrowed down to a sticky fca and bad pressure relief valve. May want to check them out if you havent yet. You can buy a rail cap to test the relief valve. Check out my thread on the idle gremlin if you havent, and see if your truck is doing something similar or not.

 

Thanks for the input. My idle is rock solid. I've run 4x the regular dose of injector cleaner as was recommended by a mechanic friend to no avail. It's got to be something. I'd like to be able to narrow it down to a part instead of guessing. My original issue was smoking and rough idle. The new injectors fixed that.

 

So to update. I've had the truck pop code P2121 and P2122. I replaced the APPS but it didn't fix the issue. I then looked at the ECM connection. It was soaked. I've been trying to clean it with contact cleaner and it fixed the codes coming back. I still have an intermittent surge so I might not have gotten it totally clean. I think I'm making progress.