This problem started towards the end of last summer. The truck will run fine when the a/c is off and it's not hot outside. Once the a/c has been on and it's say 85 degrees or higher outside and the truck has been idling in traffic or something that will build alot of heat up, it get's very sluggish when pulling off from a light. Once you get moving, say 20 mph or so and give it more gas it goes on like normal. I had to replace one of the ignition coils last year because it would start to get a bad miss when it reached normal temp. Should I go ahead and replace the rest of the ignition coils? I've already replaced the spark plugs, air filter and fuel filter during regular maintenance. The truck has ~122k miles on it.

 

It's normal for these cars. The hotter the air gets under the hood the more sluggish the off the line performance, especially if you have one of the FIPK's that don't seperate the filter from the engine compartment. Somebody posted some numbers on an older post that said you loose a couple of horses for every degree over 85.

 

It's most likely the cooling fan. At a stop, it's hot, rpm is low and the clutch engages the fan more. When you take off, the fan is a huge load on the motor. After a few seconds of the engine revving and speed increasing, the fan starts to dis-engage again and it's feels less sluggish.

I notice the same thing here in AZ in the summer.

--Dan

 

Well I got to searching around the site for awhile and did find something about a TSB referring to this issue. It was something about Ford having a reflash for the computer to correct this. I think I'm leaning more towards the fan as well since I never noticed this problem until late last summer and now this summer (it's been around 95 degrees everyday here for the past few weeks with moderate humidity).

 

Ya, I saw that too and asked my dealer to address it when I took my car in prior to it turning 100K and losing my warrenty. They said they'd do it but from previous customer reports it does not work. Here's the TSB:


Engine - Lacks Power in High Temperatures
Article No.
02-12-3

06/24/02

^ DRIVEABILITY - ENGINE LACKS POWER WHEN
OPERATING IN HIGH AMBIENT TEMPERATURES
ABOVE 38C (100F) - VEHICLES EQUIPPED WITH
5.4L ENGINE ONLY

^ ENGINE - 5.4L - ENGINE LACKS POWER WHEN
OPERATING IN HIGH AMBIENT TEMPERATURES
ABOVE 38C (100F)

FORD:
2000-2002 EXPEDITION, F-150

ISSUE

Some vehicles equipped with the 5.4L-2V engine may exhibit a lack of power condition when operating in ambient temperatures above 38°C (100 °F). This may be caused by the Powertrain Control Module (PCM) calibration which retards the ignition timing to prevent detonation when the Inlet Air Temperature (IAT) reaches 60°C (140 °F) or above. This may be more pronounced during stop-and-go driving.

ACTION

Verify the condition. Reprogram the PCM with the latest calibration and on 2000 and 2001 F-150's, install body plugs behind Coolant Overflow Bottle if missing. Refer to the following Service Procedure for details.

SERVICE PROCEDURE





For 2000-2002 F-150's and Expeditions equipped with a 5.4L 2V engine, if a lack of power occurs only when the IAT is above 60°C (140°F), reprogram the PCM to the latest level calibration as shown.





For 2000 and 2001 F150's, install Body Plugs (383181-S and N807093-S) behind the Coolant Overflow Bottle. Refer to Figure 1 for location and plug button installation. These plugs will reduce the engine compartment heat moving into the air cleaner inlet area.

Body Plug Installation

1. Remove air cleaner inlet. Refer to Section 303-12.

2. Remove jack handle.

3. Remove upper radiator sight shield.

4. Disconnect radiator overflow hose from radiator to degas bottle.

5. Position degas bottle away from body plug hole area.

6. Install body plugs in location shown in illustration.

7. Position back degas bottle Torque to 9 N.m (80 Lb-in).

8. Connect radiator overflow hose.

9. Install upper radiator sight shield.

10. Install jack handle.

11. Install air cleaner inlet. Refer to Section 303-12.






Parts Block





Obtain an Authorized Modifications Decal (FPS 8262 obtainable through DOES II, 25/pkg) and list the date, dealer number, and summary of modifications performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage And Emissions Warranty Coverage

OPERATION DESCRIPTION TIME

021203A Reprogram Powertrain 0.6 Hr.
Control Module: 2000,
2001, 2002, F-150, F-150
Super Crew, Expedition

021203B Reprogram Powertrain 0.9 Hr.
Control Module And Install
Body Plugs If Missing:
2000, 2001 F-150, F-150
Super Crew

DEALER CODING
CONDITION
BASIC PART NO. CODE
RECALEM 42

OASIS CODES: 614000, 614500, 614600, 622000