Power loss/poor throttle res. in 2006 5.4L

[Gruz7]

I know, there are tons of threads with probably the same title but hear me out if you will...

Yesterday (7/24/16) it was about 94°F I loaded up, maybe, a 400 lb total weight trailer with one canoe. Expy towed it fine like usual. I drove 1 hour down to the canoe spot and ended up having to take a dusty dirt road following my buddy in his 5.0 F-150. Needless to say the dirt the road was very dusty and my truck and his got covered in dust form the road.

I was dropping off the trailer late that night after having some minor quirks on the drive home with the accelerator and heading up a slight grade to my buddy's house I noticed the low end of my gearing had little to no power (I was on the highway driving home therefore didn't notice) and I had to punch it to get the truck to downshift so I could get power from the high end of the previous gear, but as soon as it shifts up I lose significant power in the beginning of each gear and it feels like it has almost no throttle response or a very bad misfire almost. Up until yesterday after towing and going through the dust the truck was running pretty good, no significant issues with the throttle although I had planned to clean it and the MAF sensor.

I dropped off the trailer figuring maybe it didn't like towing the 400lbs but it was still there, same issue without the trailer, that night washed the truck thoroughly outside and underneath but didn't really tackle the engine bay too too much.

Is it possible this could just be a dirty throttle body? MAF sensor, air filter, fuel filter or something? Or do I need to look into the fuel pump/tranny and such?

Here's whats been done (Motorcraft parts only):
- Fuel filter has 7k on it
- Spark plugs have 12k on them (COPs are original think they need replaced)
- Air filter has 7k on it
- Oil filter has about 1k on it (full synthetic Mobil 1)
- VCT solenoids have about 0.7k on them
Everything else I consider to be original as the PO was only noteworthy with oil changes, so:
- COPs never been checked-changed
- Throttle body never been cleaned
- MAF never cleaned
...and so on...

 

[Jb14]

Cruz I had a similar I replaced the plugs and COPs plus cleaned the MAF and throttle body just about a month ago (fuel filter was changed within the past 6 months so I did not change. Anyways with the work done the Truck did not have the issues as described, but there was still something off felt like trans and then 2 weeks ago I lost OD in middle of desert on the 15 heading to Nevada. Luckily turning off OD the main gears worked but still felt like lose of power. I will be picking up my truck today rebuilt with all upgrades plus shift kit. I will let you know if that cured the issue. So the trans this is just a heads up

 

[Gruz7]

Cruz I had a similar I replaced the plugs and COPs plus cleaned the MAF and throttle body just about a month ago (fuel filter was changed within the past 6 months so I did not change. Anyways with the work done the Truck did not have the issues as described, but there was still something off felt like trans and then 2 weeks ago I lost OD in middle of desert on the 15 heading to Nevada. Luckily turning off OD the main gears worked but still felt like lose of power. I will be picking up my truck today rebuilt with all upgrades plus shift kit. I will let you know if that cured the issue. So the trans this is just a heads up

thanks for the input, have just about all of that on my list of "to-dos".... now you've got me really hoping mine is not the trans, lol

 

[Jb14]

I had 246k on clock before OD went out but still feel I got good use. The OD issue is known issue a $5 clip ring busts where servo is and no OD. But with that amount on the clock plus my 35" thought it was time to get it done. One other thing regarding the COPs. While doing research on COPs everyone was having issues with non OEM from MSD to accell. The OEM can handle up i think 700 HP. I did not want to spend for OEMs so I used the Standard Motor Products COPs. SMP is not aftermarket and is and OE supplier so far I have been very happy with them so just food for thought when you are researching.

 

[Gruz7]

Well I'm thinking that the truck is in limp mode, (that's how severe the power loss is). I have no CEL still and it almost won't go at all unless I punch it then it will go through the gear slowly and get me up to normal driving speeds (40mph).
I am currently disconnecting the positive cable on the battery for 20 mins and then I'll test again... After this I'll be cleaning the throttle body and MAF sensor no mater what the outcome

Edit: so after test driving again I'm starting realize what the issue is a little more... Seems like along with the poor throttle response and bogging/lagging it appears to shifting through the gears too fast.

From a stop in Drive, it will rev to 1k then shift then to 1k again then shift and repeat this all the way to about 5th gear and, mind you, at this point I'm only going about 20 mph

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[stamp11127]

Sounds like a failing MAF.

 

[Gruz7]

Sounds like a failing MAF.

Even with the odd shifting conditions that I am experiencing?

Also if it is a failing MAF could this be solved by possibly thoroughly cleaning the MAF instead of replacing it?

Thanks stamp

 

[Habbibie]

Doesn't sound like a transmission failure, cause at the high end of the gears torque is at 100% efficiency even with a blown trans.

My recommendation to you is clean the MAF first (though I'm leaning towards pcm/ecu than a MAF) if it helps the situation or slightly improves it but not fully restores normal driving behavior then do replace it, if no improvements occur then it's not the MAF.

Do you have any pending codes? CEL light doesn't have to be lit for a pending CEL, I say that cause the MAF is an electronic part and its failure should trigger a response from the ECU and give a CEL but not every car is built equally.

If MAF is not the issue, call a few local repair shops (independent private owned shops) and ask if they can or would read your PCM for you to pin point exactly if this is an electrical/ignition problem or something mechanical instead.

Best of luck bro, keep us updated.

 

[Gruz7]

Doesn't sound like a transmission failure, cause at the high end of the gears torque is at 100% efficiency even with a blown trans.

My recommendation to you is clean the MAF first (though I'm leaning towards pcm/ecu than a MAF) if it helps the situation or slightly improves it but not fully restores normal driving behavior then do replace it, if no improvements occur then it's not the MAF.

Do you have any pending codes? CEL light doesn't have to be lit for a pending CEL, I say that cause the MAF is an electronic part and its failure should trigger a response from the ECU and give a CEL but not every car is built equally.

If MAF is not the issue, call a few local repair shops (independent private owned shops) and ask if they can or would read your PCM for you to pin point exactly if this is an electrical/ignition problem or something mechanical instead.

Best of luck bro, keep us updated.

Thanks, and I plan on that today.. The MAF is really what thinking/hoping that it is but no CEL is what is making me lean towards to other things I plan on taking it to a repair shop to see if they can find any codes in the system that didn't throw a CEL


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[Gruz7]

So today I've just taken off the throttle body and cleaned it...

as soon as i removed the airbox i saw that the throttle body butterfly was not sitting close to flush at the angle it is supposed to be and that the way it is air can pass through on top and bottom of the butterfly, (maybe TPS?).

Anyways it was super dirty so i used the entire can of CRC TB cleaner and a toothbrush and paper towels and did the best I could, right now its drying in a safe place so nothing gets in or on it.....
Heres some pic of the throttle body... "pardon my snapchat geotag" lol

Im going to clean the MAF now and possibly do some searching on the f150 forum to see if my TPS has gone bad given the offset of the butterfly.
here it is after cleaning by the way, mind you, the blackness you see is shadow from poor qual. camera.

 

[Gruz7]

Well now that I've done some research I think it is supposed to have a slight gap on top and bottom of butterfly and it isn't supposed to be flush.... Correct me if I'm wrong


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[stamp11127]

I'm not seeing any pics, only place holders.
If the tps is going you will have a dead spot or the pcm will throw a code for the voltage being out of range.

 

[Gruz7]

So the throttle body i cleaned a bit more and and MAF was cleaned and also i put on a brand new air filter... all back together i drove the truck down the road for about a quarter mile and it almost seemed fine but i stopped at the end of my road for a moment or 2 and got going again and it did the same thing only a little bit less aggressive.
What it is doing is shifting slightly early and then bogging down and slugging while i'm pressing the accelerator. it gets up and goes if i punch it but it still have even some bogging and bucking with the throttle matted. *seems to be the worst with light/moderate throttle...
anybody have any ideas?
thank you guys so much!

 

[stamp11127]

I would take a look at the tps operation next if you have access to a good scan tool that is able to log data on specific inputs.

 

[Gruz7]

I would take a look at the tps operation next if you have access to a good scan tool that is able to log data on specific inputs.

been testing things all night stamp with help from my uncle and found out the truck stuck in 4wd... it was a bad IWE solenoid, luckily i had already bought the updated solenoid so i installed it and fixed that problem but i still have the same issues as before...
before reading your post the nest thing i was going to check was the TPS.. my uncle has a great scan tool at his house and i'll head down there tomorrow to test the TPS and see if it needs replacing.
thanks once again for all the help guys as always

 

[Habbibie]

I would take a look at the tps operation next if you have access to a good scan tool that is able to log data on specific inputs.

That's what I suggested he do if the MAF doesn't fix the problem, also reason I said go to a private owned shop is cause they'll prolly do it for free compare to a big corporation like Firestone or similar companies.

 

[Gruz7]

That's what I suggested he do if the MAF doesn't fix the problem, also reason I said go to a private owned shop is cause they'll prolly do it for free compare to a big corporation like Firestone or similar companies.

Idk if you already my post in response to stamp but mu uncle is a retired mechanic, over 30 years, and he has an excellent scanner at his house i'll be headed down there tomorrow and see what its telling me.... on f150 forum there is a group of people with the same exact issue and one guy had his fixed when he simply got a reflash at the stealership... sounds somewhat convincing but might not be my issue... i'll know tomorrow afternoon and post promptly
thanks

 

[Jb14]

The TB on our vehicles do not close flush. I would be interested to hear your results, just a couple months ago I developed an occasional dead spot. It is hard to diagnose since it does not happen all the time and only when almost flooring it and it will go flat as though not getting gas. I replaced, plugs, COPs, cleaned MAF and TB. I am thinking it may be a reflash. I read about 4 years back that Ford had an issue in this regards and a reflash fixed the issue.

 

[Gruz7]

I'm leaning more and more towards the reflash... im going to scan it all today so i'll see anything pending and all percentages and that should give me a good idea... i got a quote from a MA ford dealer for a reflash at $112...

 

[Gruz7]

Well today i tested about everything i could in a driveway an we are thinking that it could be the shift solenoids in the tranny... reason being is that everything seems relatively of ok but the tranny shifting way too early on its own is what is seeming to be the problem .... will do some more tests and scan a bit more tomorrow so i know for sure