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I have a 2006 6.0 with apprx 125k F350 that I haven't had any problems with until now. I was running errands and as I pulled thru an intersection from a dead stop I noticed a lurch and now it runs rough like a cold winter start but all the time. Is this something easy or am I looking at taking this into a Ford service department. I planned on opening both fuel filters tonight with the thought I sucked air into the lines. Please help I'm at a loss with diesels. Thanks so much
My mpg before this happened was real good and I have only put maybe 10 miles on it since it happened. My filters were changed late February. I assume you talking dash guages and yes I have some and they are reading fine and it didn't trip a sensor
If you said it is acting like a cold start I would think that you already have a problem with your FICM and now it is just getting worse??? How about your Battiers and you charging system. I would look at them along with your Fuel mybe bad?????
I was wondering about bad fuel since about a week before this happened I had to take a 200 mile round trip and on the way back I had to get fuel at this no name hole in the wall place. Excuse my ignorants but what is a FCIM?
Ok so I just googled FICM and watched a video of a mechanic replacing one on a superduty and when the truck was running before replacement it sounded identical to mine. I'm thinking it is shop time as again I'm not mechanical with the diesel quite yet. Thank you so much for your advise and assistance.
My mpg before this happened was real good and I have only put maybe 10 miles on it since it happened. My filters were changed late February. I assume you talking dash gauges and yes I have some and they are reading fine and it didn't trip a sensor
No NOT dash gauges, but REAL gauges, like the Scan Gauge II. The dash gauges are just indicators.... or idiot lights with a needle.
You can check the FICM without gauges or Scangage. Just need a voltmeter, and instructions are in the tech folder.
It only takes one bad injector to make it run like you are describing, and it may not throw a code until it gets much worse.
I'm all for a Scangage, but no guarantee that it will pinpoint the problem, especially if it is a bad injector. Kinda hate to tell newbies to spend money on a gauge that spends their money and doesn't really help the problem at hand. Some here sound like a Scangage broken record after a while.
I would suggest you check your FICM with a voltmeter. Be sure to check it after an overnight cold soak, during the WTS period, during cranking, after starting, while cold and while hot. If it checks out okay, then you're going to need to visit the dealer or other tech with IDS or at least Autoenginuity to run the injector tests.
Check your batteries too. Just because they started the truck does not mean they are doing the job.
I was having the same problem with my truck and tested my FICM. It tested at 44 volts so I took it out and sent it off to FICMrepair.com. They just received it today. It was so easy to test and take out so dont take it to the dealer. You can save a grand by doing it yourself. It cost me $375 to get mine repaired and also have an 80hp tune put on it.
First thing to check is fuel pressure and FICM voltages. If you have not had the fuel pressure regulator spring changed out to the current spec spring, you can damage injectors easily. Fuel pressure can be checked with a gauge and adaptor to the test port on the fuel filter housing on top of the engine. You want 60 psi ideal, 50 psi is the lower limit. Good news is changing the spring is easy and not expensive. Bad news is that if injectors have been damaged they won't get better, they have to be changed. For me, testing and verifying fuel pressure is step one, do not pass go without it. Really really important.
FICM voltages are easy to check - the Scangauge II at $150 is probably less than a diagnostic check at a dealership. You want 48 volts, 45 volts is the lower limit. The FICM is what fires the injectors, btw. Running rough usually means one or more injectors have given up the ghost...
Ok. The one thing I didn't say was it starts fine as in fires right up then starts the "rough" idle. When driving it isn't. Really noticable it is only when in idle or at a stop light. I will def. have to check the voltage on the FICM and I have had this truck for just under 2 years and personally haven't changed anything to include the fuel pressure spring. Thanks for the info
It isn't likely that low fuel pressure would cause it to idle rough. So, while I agree that FP is very important to protect the injectors, I don't think it will cause this issue and you can put that on the back burner for follow-up later.
Does it smooth out when the engine warms up? Missing at cold idle only can be simple stiction.