Hey,

I recently purchased a 2005 Ford F-150 4 door with a 4.6L Triton and I started it about a month ago and the rpm's went up but then went straight back down and died. I tried starting it again and did the same thing for the second time. The temperature was about 60 degrees. I tried it again and added some gas and it came back down to idle. It chugged and died a few times more and I finally made it into town and purchased a Motorcraft Airfilter for it. No check engine light was present. It cleared up for about 2 weeks until it came back again. It's been getting a little bit worse each day. I drive about 15 miles a day. I will be driving and the truck will drop RPM's and come back up with my foot firm on the accelerator not adjusting it. It will die sometimes when I let my foot off of the accelerator when i go to brake or go thru an intersection. When it gets real bad the Check Engine light will come on. It will then run better for a while until it mysteriously shuts off. I haven't been able to run the codes while the check engine light has been on. The same problem happens if the Cruise Control is on, The A/C turned on both the Cruise and A/C on. It stays pretty constant. I have taken off the MAF sensor and sprayed it down really good with MAF cleaner and I have cleaned my throttle body with some throttle body cleaner spray that i picked up from Carquest. Lots of people have been suggesting it's the IAC. There is no IAC that I know of on it. I'm not sure if all the 05's are the same but the throttle on mine is electronically operated.

So if anyone has any input on what it might be please give me a holler back! Thanks,

~Will

 

almost sounds like a vacuum leak

 

i just dropped mine off for this problem, id be driving about 20-25 mph and the trans would slip outa gear rev up and go bac to a normal rpm ....

 

You can run codes even after the light goes off. they will be stored in memory

 

just got my truck bac from ford for the rpm jumping trans thing. whatever it is idk.. they didnt find anything wrong with it.. of course i drive off the lot about 3 miles down the road it does it.. i wanted to drive it into the nearest pole at that point.. so i went bac took the service guy for a 20 min ride... he wanted coffee.. lol and of course it didnt do.. these trucks must know when they r at the shop!!!!

 

Alright I just got it scanned today finally 5 came up total. 3 of them were stored in Keep Alive Memory the other 2 are still current. Here's what they were.

P0171
System too lean Bank 1

P0174
System too lean Bank 2

P0106
Map Sensor

These next 2 are the current ones....

P061B
Internal Module Torque Calculation Performance.. (?)

P02106
TAC system Forced Limited Power


I have noticed the other day I was driving and my torque converter was in the "Lock-up" Posistion, somebody told me that they engage at about 30 mph these days, and when the engine RPM dropped I could feel it all the way through my drivetrain and i can hear a nice warm feeling "clunk" coming from my rear end....

Not to get off topic but here's the scenario I'm in.
My Scenario is that i'm 19 years old and pretty poor college kid. (I'm sure almost everyone reading this has been here) I am going to Fox Valley Technical College in Oshkosh, WI and I'm attending the FABTECH program which is a school set up by FABCO. Fabco is the Caterpillar Dealership throughout Wisconsin and Upper Michigan. All the training that i get is Caterpillar Specific. We do work on Allied equipment as well such as JLG and Genie. I am going as a Construction Equipment Technician. I am learning tons and tons. it is awesome and the best investment that I have ever made. I purchased this truck with some extra cash that I had laying around and got a pretty good Deal on it. Wondering if it was a good investment seeing as it's only has not even 60,000 miles on it. But i'm hanging on to it and need to get it repaired.

So if anyone knows any more with these codes, some tests that I could do or maybe even has experienced this problem before let me know please! Thanks everybody!

~Will

 

My bet is a large vacuum leak. Look hard. with everything buttoned up, spray some carb cleaner around the intake manifold and the vac ports. you could cap off the vac ports to the TB and do that. probably give better results. If the rpms change when spraying in a certain area, there is something sucking air into the manifold that isn't supposed to be. Quick sprays of the can is all thats needed, but get as close to stuff your checking as you can, Use the little red straw on the can.

 

I'm guessing your truck has been tampered with by somebody trying to enhance performance with some kind of 'chip' or re-programming. My object in this case would be to get it back in original condition if possible. They may have goofed-up the vacuum lines in the process. I know it looks like a can of worms under the hood, but take some time and look very closely to see if you can detect any evidence of non-original work or parts. Obviously a piece of tubing not connected on one end would be a good clue, but it may not be that obvious. I'm out on a limb here but maybe the engine-control module will have to be 'flashed' to be reset.

 

I was gonna say Map Sensor or O2 sensor...

 

I don't belive that the truck was tinkered with. I did purchase it from an elderly gentleman he was in his late 60's. The truck did run very good and it started having this issue about a month after I bought it. Tomorrow after class I'm going to inspect all of the vacuum lines and spray some carb cleaner around and plug some TB ports. I went to a Ford dealership here in Oshkosh, WI they told me that it could very well be just re-programming the computer. I'll post tomorrow with my results.. Thanks for input!

 

well i had my 04 screw 5.4 in last week for same type of problem ,it had 2 bad plugs and coils . they also had to reflash my computer . i did get lucky and had to pay for just 1 coil when i left dealership it ran like crap so i took it back and they found the 2nd bad coil

 

Alright, Sorry for the Delay everyone. I replaced the Fuel Filter, The old one was quite a bit of resistance blowing thru it. I took it out for a drive and it ran great for over 40 minutes! It was prime time for it to malfunction too, it was cold about 38 degrees and rainy... I brought it back, shut it off, ran into the dorms here and changed went back out and started it back up again and started doing the same thing, the rpm jumping? I have put this together as the bottom line...

The Truck will run perfectly fine when i first start it up doesn't matter what temperature it will run awesome until I shut it off after it has reached operating temperature.... If i shut it off in the meantime before it has reached the operating temperature it will continue to run fine.. After it has reached temperature It decides to start dropping in rpms... It almost seems like it's starving for fuel..... The next thing that is wondering me is could it be the fuel pump? I want to get a pressure gauge on there during a cold start up and once it reaches temperature I want to shut it off and start it and put the pressure gauge back on and see what I get for a reading... I know it sounds like i'm jumping to conclusions a little bit but I doubt the fuel filter has ever been changed in life of the truck which is very close to 60,000 miles.. and the Fuel pump for how powerful it is and pushing against a resistance trying to get through the filter I am starting to believe that might be it. I am kind of doubting the gaskets becuase I remember I worked on a 2004 Ford Taurus and the sypmtom on the vehicle was when it first star
ted it ran poorly and once it warmed up it ran awesome due to the metal expanding and sealing up again. And with my truck it is just the opposite...

Anyone else agree with me or relate?

Thanks,
~Will

 

I have a 2007 ford freestyle i am getting a p061b. I am reading that the issue is the throttle body. Can some one tell if this is true or not. Also I need a picture to see if I can clean it out.