GooseF150

GT350....In your original post you mentioned power loss while driving and being able to accelerate just very slowly up to about 60mph. How about in park or nuetral? What happens in park if you ramp up the throttle quickly or do a really fast snap throttle? Does it rev up normally or does it fall on its face the same as if you were in drive?

redfishtd

I am just about out of bullets . This thing should be setting codes . It should be lean or rich or something . No timing hints.I am surprised you could see runner move as it is determined by load from pcm .
Out of desperation, you have looked at your FPDM on your rear axle for corrosion ?Its back to fuel/air /spark . After that I guess testing/ cleaning injectors . The alternator must be in good shape as it can raise hell with this engine as I have seen those posts .
Still thinking

Eric Kleven

Is it a FFV truck?

GT350

It’s not a FFV engine.

Setting still in Park, reving it up feels week and flat, about the same as driving. Which make me feel engine and not that the rest of the drivetrain is holding it back. After getting it back together, going through a heat cycle to get any air out of the coolant system, I reved it up and knew immediately it had the same problem before I test drove it.

No Codes ever.

I had runner movement setting in Park, wife punched it and it moved quite a bit. Repeated it several time. As mentioned, clips are in place and both linkages are connected and operating.

Both CAT temps are running identical which makes me think there is not anything wrong with one injector or that bank would be hot or colder. Old CATs were perfect which also makes me believe it is not running lean or rich.

I’m not familiar with the FPDM, my Ford manual says it above the spare tire. When I have it in the air tomorrow I’ll check this out. As far as rust, I live in central NC and there is very little rust on the underside of the truck so I don’t think I’ll find it in physically bad shape. I haven’t found their test procedure but I’ll look some more.


Here are my next plans:

I ordered a set of Motorcraft fuel injectors coming tomorrow. I plan to change these out first and then do the next two test.

I do have a boroscope coming tomorrow as well and I plan to look down each intake runner and verify the butterfly valve for each one is moving with the runner shaft.

I also plan to pull the first set of O2 sensors and boroscope the CATs. Since Ford did a “Power Flush”, I wonder if I have carbon flakes washed up on the inlet side of the CATs?

Thanks guys!

redfishtd

Axle is steel surface, back of fpdm rear is cast aluminum . Electrolysis eats right thru alum back . If its not bad yet it will be .
New ones are mounted on plastic stand offs , dorman okay for this . This is a plug in item .
https://www.f150forum.com/f4/fuel-pu...-yours-152908/

GT350

Replaced the fuel injectors today, no change in performance.

Haven't had a chance to boroscope new cats and intake runner as planed. Will be gone for a week or so before I can get back at it.

Thanks for the link on the FPDM issue. Not sure I buy the electrolysis theory since there are so many other areas of a vehicle that have aluminum to steel matting surfaces. But I do see where dirt and other road debris can accumulate in the mounting area and hold moisture and or salt. Using spacers removes the crevice and the likelihood of buildup in that area, which is a good idea.

I've read up on the FPDM and since it regulates the pump to regulate the pressure to the fuel injectors based on signalling from the PCM, I can see where it could cause a performance issue. I do struggle with the fact that my fuel pressures were with in FORD specs at idle, run and a leak-down testing. Maybe the fluctuations are so fast the gauge is not catching the changes. My readings were stable.

I think if I had a good scanner (and enough time to figure out the data) I might be able to resolve this issue. I've been looking on Craigslist for a good used scanner in the 300 to 600 price range. I talked to a shop mechanic that has one that cost $15k, but after going through all I have done and he drove it as well, he really didn't want to take the time it will likely require to figure it out. Again, no help from the so called Pros...disappointing.

Thanks again...

snrusnak

Hey there, I know this thread is several months old but I'm hoping you found your issue and are still on this forum! I am having the same issue with a 2005 f150 fx4 5.4L that I just inhereted. It has no check engine lilght or codes, runs fine, gas mileage is what it should be, and has good power up to about half throttle then falls pretty flat. 0-60 time is 14 seconds. I also just put long tube headers on it with an slp exhaust (no cats), a s&b intake, and had it dyno tuned. It made ~150rwhp. Something is definitely wrong but the truck runs great, other than no heavy throttle power.

If you found your issue could you please post back. Thank you.

jaiello

I have a 2006 Lariat 5.4l 3v and mine has the same issue. I was hoping it was the intake runner control module. I do have the CEL on and thats the code it throws " intake runner control bank 1,2, stuck open". Have not had a chance to get it repaired yet tried do it myself but with work and having to remove the intake. I just do not have time. I have a scanner so I check the code every once in a while to make sure no other codes are popping up. Twice now on initial set up the truck threw "cat innefficieny or something code".
The issue is that going up hills or on the highway, when you need it to perform it feels like a 40 ton brick. I also think that my MPGS are suffering I get a range from 11.8 to 12.1. I hope its that runner module , I have no way of checking it since its buried in the back against the firewall and it activates under load or acceleration. You would think with a part that important and that needed to be changed these bright and extremely smart ford engineers would of put it somewhere you could change it, but looking at the spark plug they decided to put on these trucks, thats wishful thinking. Anyways I am going to try to get this repaired and post if it works and hopefully that can help you diagnose yours.

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...