I’m new to the diesel community so please cut me some slack. I recently bought a 6.0 Powerstroke with ARP studs and an EGR delete. After buying the truck, it started smoking terribly very soon. I replaced all 8 fuel injectors and found 2 blown ones, so that problem is fixed now. Then I got a turbo underboost code and experienced a rough idle, which put the truck into limp mode. I checked the MAP tube, EBP sensor and tube, and rebuilt the turbo. The truck ran fine for a day or two, but then it started idling rough again and I’m losing power once more. Here’s a video of some PIDS I have on my Edge CTS3 Monitor.
If anyone can point me in the right direction, I would really appreciate it. I’m scratching my head over this one.
You should always check the FICM first before messing with the injectors. A good shop can have a known good FICM to swap in and rule it out. I had a bad injector code once, and it turned out to be the logic board in the FICM. Also, make sure you’re getting the right fuel pressure and have good airflow. A big boost leak can mess with your turbo. Start with the FICM and check everything else.
Jess said: @Ocean
The FICM voltage is right where it should be. Does that mean the FICM is good or bad?
You can’t tell everything just from the voltage. My voltage was fine, but it still needed to be ruled out, along with fuel and air. Once those are okay, you can move on to the next steps. You should watch Diesel Tech Ron’s videos on YouTube for some helpful info.
Jess said: @Ocean
Now the truck is running like it’s brand new again; it seems to be an intermittent issue.
It’s tough to track down something that comes and goes like that. My AC compressor failed and left me stranded. It slowed down the engine so much it wouldn’t start. Good luck, and definitely check out Diesel Tech Ron. He passed away in a car accident, but his content is amazing.
Did you put stock injectors back in? It sounds like you’re missing something. It could be a typical bad injector letting combustion pressure into the fuel system. A balloon test is a quick and easy way to check.
You’re not building any boost. Are you sure a CAC boot hasn’t slipped off or is letting out a bunch of boost? Also, you said you ‘rebuilt’ the turbo. What exactly did you do?
Sawyer said:
You’re not building any boost. Are you sure a CAC boot hasn’t slipped off or is letting out a bunch of boost? Also, you said you ‘rebuilt’ the turbo. What exactly did you do?
I cleaned it and changed all the O-rings and bearings.
With the P0299 code, check the MAP sensor hose. It’s prone to slitting or getting a pinhole in it, which can cause a lack of boost. If the PCM doesn’t see any boost, it won’t compensate correctly with fuel. If you’re in the SoCal area, I can help you with this.
Jess said: @Ben
I appreciate the offer, but I’m on the other coast, my friend. Thanks though.
I work on the 6.0 for a living. It’s a great motor despite what people say. I love my Choate powered diesel. If it has a lack of power and isn’t building turbo boost, check the MAP sensor hose from the MAP sensor to the intake manifold. It tends to get hard and crack.
Jess said: @Ben
Mine looks newer; it doesn’t seem old and cracked. Should I just replace it to rule it out? And should I also check the FICM and fuel pressure?
Yeah, I was starting with the basics that everyone overlooks. 50-55 psi is normal fuel pressure. The FICM power should be a minimum of 12 volts in and 48 volts out. I’ve seen them drop as low as 45 volts. If the FICM power is off, it should throw a FICM performance code. Since you’re only getting the P0299 code, I’d focus more on the MAP sensor, back pressure sensor, and turbo actuator solenoid. The turbo solenoid connector can also be damaged, which can prevent the turbo from spooling. Do you have access to any good scanners? Like Auto Integrity or Autel or Snap-On? Fuel pressure is tricky unless you have the fuel caps that have a 1/4 hookup on top. Otherwise, you need to go down to the fuel conditioning module and test at those connections.
Thanks though.