I have 2001 F-150 with 4.6L. Truck runs fine until under load and runs fine until I slow down to a stop sign. Once truck sits for a few moments it fires up again and will run for a short while then will do it again. Each time i let it sit for a few minutes, it will start again.
I pull a small travel trailer and seems to happen more frequently when pulling or climbing hill, but not under full power, just when slowing down. Could this be cause of catalytic converters? MAF sensor, or fuel starving.
check engine light is on, will codes identify if it is a plugged cat?

 

If this is an automatic, your symptoms sound more like what's going on with my Ranger. Runs great when cold, worse when warm. Coming to a stop, idle sits at 600, then fluctuates when the truck gets really hot. Sometimes will die. When the truck is put in park or neutral, i.e. load taken off, the idle returns to 800. You may want to look into your torque converter lockup, your TC may not be unlocking when coming to a stop.

When towing it is always recommended to manually use the overdrive switch to turn off overdrive, especially when going up hills. Towing will easily fry a transmission under these conditions.

 

What does it do, specifically?
What are the codes?
You have not given enough info yet.

 

It seems to be when truck gets really warm after climbing a long hill or pulling a trailer. then when I slow down it cuts out completely, but then will restart after being shut off for a couple of minutes. Only code that came up was EGR valve.

 

WHAT code is it?
The codes do not tell you what hardware is faulty, only the system in fault and what the test failure was..
Still not enough to go on except it may be an overheat issue and may be related to the EGR system.
We are trying to help you. Come back with the code so some relationship might be established to help solve the issues.

 

We do need to know the Codes, but it sounds like your EGR valve is sticking open when it's hot. You could pull it and use a soft brush to clean it, while exercising it with a hand vacuum pump. Mine seemed to be Wide open at 8" of vacuum. I would put no more than 10" on it. If you use a carburator cleaner on it, hold it right side up and spray, while exercising the valve. Do not get the spray on the Diaphragm!!. Ford does not recommend cleaning the valve, this way, but I'm not sure why. Don't let it go too long, you could damage engine valves, and/or the converters.

 

What was the fix? I have a 2004 Excursion w/ 6.0L and when I'm under load (~8500lbs) it starts running rough and slowing down once I pass 55mph. It then continues to run rough until I pull over, turn the key off, count to 10 and start it back up. Of course no indicators or codes are generated.

 

Hey guys. .I have 2 99 f150s. The extended cab that fits my kids will stall when I hit the gas while in any gear. Rpm stays the same.. sputtering isn't what it does. It goes silent and just starts running again when I let off the pedal. I've used parts from the other that had no issues and swapped the fuel pump, filter, tps, swapped injectors, cops, tcc solenoids , vacuum lines and a few other partside I had to buy. . I've been out of work for 2 weeks because this truck carries my kids and my tools.. I've spent every dime i had and got way behind trying to figure this thing out. Can anyone please help

 

 

If the motor cranks and starts it's not a power or starter issue.
This wild parts changing and all the labor involved does no good hoping to get lucky, as you found out.
.
The motor needs fuel to run, have you tested fuel pressure with a gauge to see?
You must do some testing to find out the general cause of the failure before changing any parts.
Otherwise your working backwards.
Doing a lot of parts changing risks generating more problems all at the same time.
.
For off idle stall if I understand you, all that happens is opening the throttle body valve and turning the position sensor.
Airflow through the Mas Air meter and some additional fuel due to the TPS is added per airflow and RPM.
Is the fuel pressure high enough to feed the motor?
There would be no reason for ignition to cut out unless it is a vibration issue with power feed to the coils or injectors.
Have you checked this possibility out?
This is all diagnostics before changing parts.
Good luck.