So I am not sure what to really think. I seem to have a very Intermitant rough Idle. There is nothing ever different with the truck when it seems to happen. It has been going on for some time now, The truck runs perfectly fine when driving down the road though.

Okay so here is the problem. On a cold start it starts up just fine and seems to have a stumble to the engine. A rough idle ( like the sound and engine makes when its about to run out of gas) for about 10 Seconds then goes away. Engine warms up and no issues at all. This happens Intermitantly.
Now this same thing happens when I have been driving for a while. Take today for instance. I started the truck (cold start) let the engine warm up. [ I usually allow between 5-10 min. for warm up. Never less than 5 min.] I drove for about 1 hour, 1/2 of that time being freeway at 65 mph. My truck drove just fine. I pulled of the freeway to where I was going, and as I was sitting at the light on the off ramp the engine had a slight lurge/ stumble/ rough idle. What ever you want to call it ( it made that same sound like it was about to run out of gas). I proceeded about another 2 miles of city driving, and it was still there. Shut the truck off for about 45 min. When I started it again to drive back home. The symptom was completely gone as if it was never there. No rough start. And no rough idle after driving.

This is why I am completely confused as it only sometimes happens and it goes away as quick as it came. The truck has no loss of power, and driving does not seem to be effected.

About my Truck:

2004 Ford F-350 CC/ LB 4x4
6.0L Diesel

Mods:

4" Lift
38x15.5x20 Tire and Rims
K&N Intake
CFM+ Intake Elbow
EGR Delete
Straight Pipe Exhaust
Coolant Filter

Custom Tunes by MKM Customs:

-Stock w/ EGR delete
-Economy
-Towing

Regularly change all filters, and keep up maintenance of my truck. I run motorcraft filters, Except the K&N intake, and the coolant filter which is WIX. This oil change I also tried out the HotShots Diesel Oil addative. (which currently has about 3,000 miles on). Don't fret though; the problem was there prior too the addative, it was also there prior to the custom tunes, straight pipe, intake elbow upgrade, coolant filter, and the EGR delete. Don't know about prior to the K&N as it was installed when I bought the truck 2 years ago.

I have also pulled the trouble codes, and there are only two which are for the EGR. I have no check engine light.

Like I said this problem has been there for a while, so I am out of ideas. If I forgot any information please feel free to ask. If anyone has any ideas I am open to any suggestions. It is more of an annoying problem more than anything seems as my truck runs perfectly fine. This problem never effects power or normal driving.

Thanks in advance for any help/ suggestions/ comments.

 

you have an injector issue

 

How do I figure out what injector is bad aside from going to a dealer. Injectors are one thing that I have never had to deal with. I prefer to do 100% of the maintenance myself if possible, as I don't trust other people to work on my truck and besides mechanics are way over priced, and most don't know a Diesel from a Gasser.

And YES I am currently Reading the Tech folder on Injectors...

 

a quality scan tool. you will need to be monitering when the concern happens

 

I have the SCT3000 X3 Power Flash Handheld Programmer/Scan Tool that I got fro MKM cusoms to load my tunes, will this work. I am not 100% sure on how to use the monitoring on it as that is all new to me. This is my first Programmer/Scan Tool. How do I set it up to check the injectors?

 

Do you gave sg2 or something odb2 to read sensors?
What about fuel pressure? Blue spring upgrade
is cheap and should be done anyway

 

Auto enginuity. It should b about $400. Get the ford bundle. It will do the contribution balance line graph.

 

I do not have a SG2, all I have is the formentioned programmer scan tool, but I don't think its going to be able to do what I need it to. I was just playing around with it, and it doesn't seem to have anything in it for injectors.

I would like to not spend another $400 on a scan tool as injectors are already going to be pricey.

 

What is the blue spring upgrade? And what was the question about fuel pressure?

 

That tool will tell you which one to change tho. It's your dime tho,,, I wouldn't give up my AE for anything.

 

I took my truck into the dealer and had them run a full diagnostics on the engine. They gave me a hell of a deal as they only charged me $80.00 for it. So when all was said and done, the diagnosis is a sticky/ weak #3 injector when engine is cold. When the engine warms up the #3 injector runs perfect. So as of right now I am not going to replace the injector.

I will be doing the blue spring upgrade... it was like $60 from my local dealer.

As long as I keep my oil changed, my fuel clean and allow the truck to warm up I think that this injector should last me a little longer. There is currently no loss of power, no smoke. When some once else is the truck they can't even tell. But who knows your truck better than the guy who drives it every single day of the week. So I know there is an issue. Injectors are about $270 with a $180 core charge. So this can wait, at least for now. Once I get the Money and time I will change it before it creates a problem.

 

It is not a bad idea to get some sort of gauge setup before things go bad as you can familiarize yourself with certain values that can pinpoint problems before they leave you stranded on the side of the road and in some cases can prevent you from doing serious engine damage, like monitoring FICM voltage, battery voltage, exhaust gas temp and engine coolant and engine oil temps. The scangauge II is very popular and is around 150 bucks from auto zone or some of the guys here have been using an app on their smart phone to do the same thing. Not sure what the cost is to set up the smart phone to do it but its less than the SGII i believe.

 

I do agree with you. I actually have plans to invest in guages or possibley a all in one monitoring system. I want to install the F-650 dash, when time permits, which I will also have guages on, so I don't want to spend to much Money on a monitoring system, when I have plans to add guages. I do understand your point though. And the last thing that I want is to be stranded along side of the road somewhere. I take excellet care of my truck and so far she has taken great care of me. Very miniscule problems. See I don't beat on my truck or try to race it like some of the idiot drivers out there. No offence to anyone. There is a difference from upgradeing your truck to high performance and just driveing like a complete idiot. I think you all know the drivers I am refering to. Point is, over the years I have found that if you take care of these trucks then they will take care of you. So yes I do have plans to add guages. It is just Money is tight right now. If I had an unlimited budget.... well wouldn't we all like that.

 

Nailed it! Great job! I hate this I can't give reps.

 

I have $35 invested in my Torque app. Works well. Still need fuel pressure and EGT gauges.