snrusnak

Look what the timing advance does when I stomp on the accelerator. It actually retards slightly then slowly advances. I would think it should advance when giving it a lot of gas, am I wrong?

PerryB

USUALLY... VCT related issues have a few "tells" to give them away, most often rattling, clacking etc. The intake runner control would be a good place to look. I hope you find your problem soon before you pull all your hair out!! My experience with the 3-valve 5.4 has been good. As stated previously, my son's '05 (which used to be mine) hauls a**. It's stock except for a Roush muffler (still has all 4 cats), 35" tires/2.5 level and 4.56 gears. The tires and gears basically wash each outer out so it should be a good comparison to stock. Its a fast truck. So was our '10 Expedition.

PerryB

Interesting dip in the ign. timing half way through the flog. I'm guessing the knock sensor heard something and pulled, then re-installed, a slightly reduced amount of advance.

snrusnak

so i just data logged with a different app that is ford specific, and it had a PID for the IRMC or whatever it's called. It never moved off 5v, which I believe is the signal for closed. I even floored it all the way through redline once and it never came off 5v. I'm wondering if for some reason the intake runner manifold controller is not functioning and the butterflies are stuck in the closed position. That could maybe explain why the truck runs good and even feels to have some power at low throttle/low rpm but falls flat at higher rpm and more throttle.

But I would think this would throw a code, and there is no check engine light....

Just an example of the voltage, this is zoomed in on when I went WOT, and sorry I forgot to log the PID for RPMS.

Of course, there's the chance that the PID I'm looking at is wrong or is not actually accurate as to what my IRMC is doing. I need a way to test it.

snrusnak

I just pulled the FPDM above the spare tire and although it was very corroded it was not eaten through. I cleaned it up and put some rustoleum on it. I didn't bother testing it as the truck runs pretty much fine other than the low power at heavy throttle. I want to check fuel pressure next but don't know where to connect, never done it before on this vehicle. I don't see anywhere to connect on the fuel rails at the engine.

I wonder if I can buy the FPDM stand off thingys on their own?

snrusnak

OK so I may be on to something with the intake CMCV or IRMC or whatever it's called.

I followed the below instructions that I found online in another thread to test the CMCV function:

"To test the CMCV actuator, disconnect PCM connector C175E. With the key on, and being careful not to spread or otherwise damage the connector terminals, ground and unground the Light Blue/Orange wire in pin 50. CMCV actuator movement should be heard as the circuit is grounded and ungrounded, and a light and mirror can be used to watch for the actuator and linkage to move back and forth. At the same time, monitor the Black/White wire in pin 43. It should show ground when pin 50 is not grounded, and no ground when pin 50 is grounded. If the actuator does not move, and/or the monitor circuit does not ground and unground properly, the CMCV actuator will need to be accessed to verify that the command and monitor circuits are not open or shorted. Also check for battery voltage to the CMCV actuator on the Red/Yellow wire, from fuse 32 in the inside fuse box, and a good ground on the CMCV actuator Black/White wire (the one next to the Red/Yellow wire in the CMCV actuator connector), from ground G103, at the rear of the passenger side fender, next to the rear of the battery. If the wiring all checks OK, replace the CMCV actuator."

I performed the above test and could hear the CMCV actuator moving but only one time. So when I grounded PIN 50 (light blue/orange) I heard the actuator then when I ungrounded it I heard the actuator again. But it would not repeat unless I cycled the ignition. I don't know if this is normal or not. I then decided to stick my hand back there and I could just barely get my hand on the end of the linkage/rod on the passener side where it connects to the shaft at the manifold. I could feel the retaining clip. With my other hand I grounded the PIN 50 and again heard the actuator noise but the linkage barely moved. Hard to say how much but definitely not 90 degrees. Maybe just a few degrees or like 1/4" at most. So I'm feeling pretty confident this is my issue, I just need to figure out how to continue troubleshooting.

I tried to monitor the PIN 43 (black/white) to see if it Grounded/Ungrounded opposite of PIN 50 but I don't know if I was doing it correctly. I hooked my multimeter up to check voltage and put the black to ground and the red to PIN 43, and it showed -12 volts when PIN 50 was not grounded and 0 volts when PIN 50 was grounded. I'm not sure if that's correct or not? To summarize:
PIN 50 ungrounded = PIN 43 -12 volts
PIN 50 grounded = PIN 43 0 volts

According to the test above, I don't think this is correct. I think it should be like this:
PIN 50 ungrounded = PIN 43 0 volts
PIN 50 grounded = PIN 43 ~12 volts

I'm wondering if the motor inside the CMCV actuator is moving but the gears to the linkage are stripped. That could explain when there's no code, as it doesn't realize the linkage isn't moving.

Any help is greatly appreciated, especially with the electrical troubleshooting, as I'm not too knowledgable with these more complicated systems. Thank you.

snrusnak

Alright, I can't begin to tell you all how relieved I am at what I just found. I ordered a little bluetooth (to android phone) boroscope thing on amazon for $35 and used it to see the CMCV in action. The little gadget is awesome, and even has a super bright light, it works great.

The driver side linkage is disconnected and the linkage is kind of stuck on a ridge of the aluminum cylinder head, which is why it is only moving a very short amount. So basically both sides of the CMCV butterflies are stuck closed.

This is a relief as I was about out of troubleshooting options. I'm kind of surprised this wasn't throwing a cel code, but I'm glad I found it. I am going to install a new actuator since this one has been bound up for who knows how long, it may be weak or something.

I think the guys who tuned it for me will work with me and tune it again for little cost, so we will see how it performs when it actually gets some airflow!!!

Here's a picture of what I found!!!

The obd is great but sometimes old school troubleshooting is what it takes...

PerryB

Good job! That ought to make it run a LOT bettet.

snrusnak

Thanks. Apparently the replacement Dorman actuators are pretty much out of stock everywhere. I finally found on but we'll see if it actually shows up, I have a feeling they will realize it is out of stock and then refund me. I guess I can get one from Ford for twice the price if need be.

Here was my FPDM. I wire brushed it, cleaned it up, and sprayed it with rustoleum then mounted it with a couple rubber spacers.

snrusnak

agh this CMCV actuator is pretty much out of stock EVERYWHERE! Jegs is supposedly shipping me one but I can't get any shipping info from them. I have a feeling it's not going to show up then they'll refund me my money and I'll have wasted a couple weeks of my life.