Hey guys,

I have a 2001 f150 supercrew with the 5.7 and 3.55 gears. I am experiencing a significant power loss after the vehicle warms up in warm to hot weather, and not too sure why. All fluids are good.

Now, I have replaced the air intake with an airaid & K&N Filter. Also added a throttle body spacer. Also have 285/75/16's, so I understand that there would be power loss with the bigger tires. And lastly I had the muffler removed, was told that with 4 cats, there was plenty of back pressure for the engine.

Hope you guys can help me out, because I am getting pretty tired of this thing running like a champ in the morning, and like a pinto by noon! Not to mention it doesnt pull worth a dam when its hot outside.

Thanks

Kevin

 

I have similar symptoms due to a failing fuel pump. Other han 90 degree days I am fine, but when it gets hot and especially in stop and go traffic, there's problems. Fortunately, I have dual tanks so it's no big deal and I just let it be. I can always switch tanks on those hot days

 

Hello, and welcome! More than likely, you don't have a 5.7, that is a 350 Chevrolet engine. Sorry that I don't have any ideas about your power loss, but someone will reply and set us straight pretty soon. Welcome again!

 

Hmm, a failing fuel pump? I don't feel any jerks, or sputtering, but it is especially in stop and go traffic, or pulling the boat. I am really needing to get this fixed, or I am going to sell it.

Thanks

Kevin

 

Is that Airaid and K&N an open element under the hood? If so, then all you are doing is sucking in the hot outside air, PLUS the hot underhood air too..... The stock unit has the air inlet sucking air from the fender, so it's taking in cooler air then what's under the hood itself.

That's just my guess on the deal.....

Good luck!

 

I have the same problem that you are talking about, I also have an intake with 33 inch mud’s and the truck will hardly get out of its own way in 90 degree + stop and go traffic. I have found a couple TSB's that might explain this condition.


Here's what 15431 says:
15431 - LACK OF POWER IN HIGH AMBIENT TEMPERATURES
Some 1999-2002 Expedition and F-150 vehicles equipped with 5.4L 2V engine may exhibit a lack of power condition when the
vehicle is operated in ambient temperatures above 100 degrees F, particularly during stop-and-go driving. By design, the
PCM calibration retards the ignition timing to prevent detonation when the inlet air temperature (IAT) reaches temperatures
above 140 degrees F. If the lack of power condition occurs only when the IAT is above 140 degrees F, do not replace parts
in an attempt to service. Engineering has developed a new calibration which will be available early in the first quarter
of 2002. If the condition exists in other temperature ranges, proceed with normal diagnostics.

Here's what 15630 says:
15630 - LACKS POWER IN HIGH TEMPERATURES - REPROGRAM PCM
Some 2000-2002 Expeditions equipped with a 5.4L 2V engine may exhibit a lack of power condition when operated in ambient
temperatures above 100 degrees F, particularly during stop-and-go driving. This may be due to PCM calibration, which
retards the ignition timing to prevent detonation when the inlet air temperature (IAT) reaches above 140 degrees F. A new
calibration is available to service this condition. If the condition occurs only when the IAT is above 140 degrees F,
reprogram the PCM to the latest level via the just-in-time process if your WDS communicates w/Fordstar. Also obtain
calibrations on the Ford Professional Technician Society (PTS) website - select 'WDS' then 'PCM reprogramming' and
click 'Instructions' for downloading. Calibrations are scheduled to be included in WDS release B17.10.


So, there you have it folks. The answer to your high temperature loss of power woes!

I have also heard that a power programmer or a superchips programmer will take care of this problem by reprogramming the calibrations.

 

Well sir, that seams to explain the problem. Mainly because the truck pulls like crazy in cool weather, but when it gets warm outside, it just plain sucks.

Here in Arizona, the temperature gets a LITTLE over 90 for 5-6 months, so for half of the year, it sucks to drive.

I was pulling the boat to the lake last year around noon time, and floored it off the line on a streight away no hills, and it barely got the boat moving. But when I took off that morning with the boat, it wanted to spin the tires right off the rims.

This TSB explains my problem pretty well.

Thanks for the help.

Kevin

 

I have read about this in past threads,, seems that when the incoming air temp gets in the 80's the computer starts pulling timing out to keep the engine from pinging..
All our 5.4 work vans do it and my wifes expedition ..

Add to that the airconditioner load and you better leave more room when pulling out into traffic.

 

simple as this. hot air expands cold air compresses. cold air=better compression hot air= less compression. understand that? so knowin that that is why your air temperature sensor when it reads over 140 retards timing because the air to fuel ratio is less so that ur dont burn alot of fuel or have spark nock really bad from the engine not gettin a good amount of oxygen to allow good combusti0n for the next stroke.

so i guess one way to solve this problem could be to get an intercooler for your intake, get ram air hood for your truck:-p or rig up a CO2 tank to your intake and when u want the boost just press a button=P

 

I am wondering if the ECM is concerned about pinging, if the level of octane would help with this ??? What octane level of gas are you running? If you are running on the low octane, it might be a good idea to increase to the next level to help when you are pulling the boat around in the hot weather. Heck, go get the ECM re-programmed instead of spending over $300 for a contraption that you need to rig up or another hood unless you are looking at another hood for the truck.

Have Fun & Keep on Truckin'
Dean

 

Everyone is right, but there actually is a TSB that causes this... Some f150's were programmed with the wrong calibrations, (LIKE I HAVE ALREADY STATED.) I know this because my 2000 f150 4x4 was one of them, and for a small 80 dollar fee ford can reprogram the PCM with the new calibrations. Or for a larger fee you can purchase a superchips programmer or a hypertech programmer. So yes heat does cause an engine to lose power, or really it just causes the PCM to take timing away from the engine to prevent detonation, but some f150s have this problem and the PCM takes too much timing.

 

First off don't sell it just caus you haven't found the problem yet. your issue is not that common. if it were you would see more of it on here. remember there are millions of 5.4's out there and they tow in any weather no problem.

I have a black on black on black f150 w/5.4 and here in Maryland we get into the 90's quite often in the summer and I tow a heavy trailer and have no problems at all.

Let's start at the begining,

has the truck always done this?
did you buy the truck new?
did it work fine after each mod you added and then just started this?
did you reset the pcm after each mod?
there are many known problems listed on this board for people with throttle body spacers and removing the muffler.
it's obviously temp related, have you checked all the temp sensors?
are there any other symptoms?

oh, and welcome to the board!! Crownlines are sweet!

 

The SuperChip programmer will take care of this problem. I did not re-flash mine prior to installing this, and the problem went away on my '01 5.4L

As for the air being hotter with a open element FIPK, this is for a very short time when comparing inner fender temps and the air temp under the hood.
https://www.f150online.com/galleries...2028-56886.jpg
I used a OM-44 temp recorder to find this out for myself.

Post on the thread topic of intake source temps :

 

SSCULLY, wow that is interesting. I knew the under hood temps in my truck is hotter while sitting and lower while driving because I have so much room in my engine bay compared to the post '97 trucks for air movement when moving. I figured with all of the extra plastic covers and all, it wouldn't be a cool as mine but I know differently know. Thanks for the research information !!!



Have Fun & Keep on Truckin'
Dean

 

i know!!! u could get like a small like 10,000BTU window unit and just like cut a hole in the hood and stick that sucker in there
and then just turn it on whenever ur engine gets hot that oughta work.... just gotta find one that works off DC.......u could disguise it as a blower....