2006 F150 5.4L Sputter

2006 F150 FX4SuperCab 5.4L new engine 

I’ve had a sputtering problem ever since I basically replaced this engine. Coil packs are fairly new got them from 1A auto not sure the brand and new motor craft plugs, fuel filter, fuel
pump control module, and battery. I’ve replaced the throttle body, MAF sensor as well as the Intake manifold with a new Dorman brand one. 

Basically it starts and idles somewhat fine for a little bit but then the idle becomes a bit erratic. 
If the truck is in park or drive and I try to apply any sort of quick throttle it just sputters like it’s out of gas and gets as close to dying as it can get without dying. If I let off the gas it returns to idle and idles pretty much fine. Warming the truck up does not change anything and I have also put a fresh tank of gas in it also. Last thing I did was replace all 4 02 sensors and took all of the injectors out of the truck and had them sent to a company to be tested for pulse rate and flow and I was told they were all good. The fuel pump is only 2 years old but it is not a motorcraft fuel pump I am unsure of the brand as I think it is from 1A auto also. Both catalytic converters are also brand new. 

Have NEVER had a check engine light to go off for this issue. Starting to think the ECM may be a culprit but I’m unsure. Truck was with a dealership in my area all last month and they couldn’t figure it out. Any ideas? Attached is a link to the video of what it is doing on YouTube as well as some basic scan data.

Thank you for the video.   Really helps when trying to give diagnostic direction.

First thing that caught my eye was the fuel trims, about -15% total on both banks. Trims improve slightly off idle. Made me wonder if the MAF is misreporting, but it's tough to gauge with the engine still warming up. Would you be willing to recheck trims and MAF g/s with the engine fully warmed up?

You can definitely hear the sputter during a throttle snap. Makes me wonder about a secondary ignition issue. Even if you don't have any fault codes setting, you can still check the Mode $06 results for misfire counts. Forscan makes this easy. In the 'tests' tab, use the 'Mode 6 - Test Results for Specific Monitored Systems' option.

 

Grab a screenshot of the results, if possible.

Tyler,

Thanks for the reply and getting the conversation going on the issue here.
I attached another link to the video and hopefully was able to get enough information for you as far as the mode 6 data and truck fully warmed up.

Just an update since unfortunately the thread ran cold almost immediately. Had the truck at the dealership for over a month and they ended up calling the engine computer bad. I replaced the engine computer today and still have the same exact issue. So if anyone who reads this has any ideas I’d love for you to chime in or provide some support.

I would take this truck for a wide open throttle run and graph my voltage and gms/sec. pids of the mass airflow sensor as my next step. I see you did replace maf but  only saw it get slightly over 2 volts on your video.

I can perform this check but could you provide insight on what this would determine? It’s been some time but months ago I checked all the wiring from the maf connector to its respective points for continuity and shorts to ground, etc. Everything was good. Ended up replacing the sensor anyways and it didn’t change anything and since now I have a brand new engine computer I don’t understand what I would be looking for in this sense. Is the current idle voltage parameter not correct? Thanks in advance.

Maf voltage should go over 4 volts and grams/ sec should be near 150 grams/sec at wide open throttle.

Understood, I’ll try and perform this check tomorrow. If you can think of anything else please let me know. Just curious if you are at all knowledgeable all the mode 6 data video that I posted earlier in the thread, do you see any anomalies or anything that sticks out by chance?

I would also check all 4 oxygen sensors. They should all go rich at wide open throttle. Find a nice hill and take foot off gas pedal on decel down the hill. They should all go lean. Keep us posted.

youtube.com/shorts/Q5vTHYVUjbQ?si=PyHt9TyYJqG77T0d

Here is the test. Biggest issue I see here is the fuel pressure looking to be varying quite a bit around the beginning of the wide open throttle test. Everything else looked normal but please let me know what you or anyone else thinks.

Fuel rail pressure dropping to 20.7 psi @4049 rpm, even momentarily is an issue. I am sure others can add to this.

Yeah man definitely. It’s strange thought I’ve never noticed that when sitting at idle and experiencing the sputter but I’ve also never done a wide open throttle test and monitored the values as I did today. Not sure why it would show during wot and not at idle unless it has something to do with the overall load of the engine. I’m going to go for the FPDM first and see if that changes anything. Everything I read saying that the fuel pressure is regulated via that component? So if I’m wrong on that please let me know. Only other thing I see in the fuel system is the rail sensor but that’s just for pressure. As said before I had all 8 injectors removed and sent to a company to be tested and was told they were perfect. But yeah any other useful information is appreciated.

Sounds like next move, but I would see if anyone has some other ideas. Happy New Year all.