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Have you checked the MAP Sensor yet. The hose from that sensor down to passenger side intake could be clogged or even disconnected. If all looks good remove the hose and blow thew one end to check for clogs. If all that looks good disconnect the three wire plug on the MAP sensor as shown on the picture below and take the truck for a spin. Your will get a CEL light but that is OK. If truck runs much better then you have either a MAP sensor failure, hose problem or turbo issue .. maybe lots of boost leaks.
Hello fellow member. You had replied to me with a question asking if my ebpv is open. How can I tell? I know the sensor closes it, so I only assumed if its unplugged it must be open. But you got me thinking, valves malfunction!
The sensor does NOT close it. The actuator does. But that's what you've (presumably) disconnected. The valve SHOULD default to full open when de-energized, but you are correct, like any valve, it can become restricted and get caught in a partway closed position.
Remove the downpipe and peer upstream into the turbo outlet. You'll see the valve plate, and should be able to tell if it's open all the way. You can also tell based on the position of the linkage, but I'm blanking on which position is fully open.....
There was a post a while ago that the valve closed even when disconnected the wiring, suspected oil pressure drove it open on a bad actuator somehow. Some have taken the actuator off and wired it open with bailing wire just to be sure. There was another that caught on their downpipe and another that would stick in the housing and needed to be ground down a bit.
It's not very often, but they will fail closed. Mine was wired open when I got it. I unhooked it just to see what happened. Idk why, but it shuts even with it unplugged. Wired it back open and all is well.
I wouldn't dismiss the fuel pressure concept unless pressure is verified. It may rev well but if the pressure is low then when the truck is under load it will not perform as intended.
Now that you mention it, check engine light has never lit up even at start up. Only wait to start, water in fuel, and fuel filter. Of course they all clear after ignition. Now I'm wondering....how long would it have been on if working?!
Take a look at post #80 first picture and you can see what that valve plate should look like in the open position when you pull the down pipe to take a look.
Check the fuel pressure at the Schrader valve on the driver side of the fuel filter housing (it may have a black plastic cover on it) and report back what you find.
Also, just pull the clamp off and check the position of the EBPV - it shouldn't take you long and that's a good thing to eliminate.
I do think your Check Engine Light is burned out, as it should come on with the MAP sensor unplugged.
If the fuel pressure is okay, the other thing to try would be to unplug the EOT (Engine Oil Temperature) sensor. I'm telling you, I don't know if it runs off the EOT or the runtime of the engine or what, but a ZF5 Powerstroke that is cold (or thinks it is cold) is one slow dog. Unplugging the sensor will cause the PCM to default to assuming that the engine is at operating temperature, which should allow the fuel map to be corrected for a normal operating temperature.
Here's a picture for reference on where all this stuff is located.
