06 5.4L V8 Lariat Low RPMs under load/Stalls when stopping
#17
02-14-2023, 09:01 PM
Stalling
2006 Ford F-150 Lariat 5.4L V8 Flex Fuel With 221,000 Miles
The issue i am having is that when you come to a stop the rpms drop down into the 300's. This sometimes leads to it stalling out, especially if I just tap the gas and then hit the break right away. If i slip it into neutral the rpms return to the factory range of about 600-700. But as soon as I put it into gear and there is a load on the engine they drop to the high 400 low 500s. I just replaced both the camshaft position sensors hoping they had something to do with it but no luck. One thing i noticed tho is when the truck does stall out the low oil pressure warning lamp comes on and it takes an extra second to fire back up. But after it is running again oil pressure is at normal range. I have an Edge CTS 2 unit so I am able to monitor all of my engines data from fuel rail pressure to intake air temperature and everything in between. Hopefully someone can give me a solid direction to look in so im not on a wild goose chase trying to hunt down the issue.
I have a DTC for Bank 2 efficiency below threshhold, I have a bad cat and its been bad for a few years without casuing any driveability issues. I have also noticed that the problem gets worse as the engine reaches operating temperature. Any and all input is greatly appreciated. Thanks
The issue i am having is that when you come to a stop the rpms drop down into the 300's. This sometimes leads to it stalling out, especially if I just tap the gas and then hit the break right away. If i slip it into neutral the rpms return to the factory range of about 600-700. But as soon as I put it into gear and there is a load on the engine they drop to the high 400 low 500s. I just replaced both the camshaft position sensors hoping they had something to do with it but no luck. One thing i noticed tho is when the truck does stall out the low oil pressure warning lamp comes on and it takes an extra second to fire back up. But after it is running again oil pressure is at normal range. I have an Edge CTS 2 unit so I am able to monitor all of my engines data from fuel rail pressure to intake air temperature and everything in between. Hopefully someone can give me a solid direction to look in so im not on a wild goose chase trying to hunt down the issue.
I have a DTC for Bank 2 efficiency below threshhold, I have a bad cat and its been bad for a few years without casuing any driveability issues. I have also noticed that the problem gets worse as the engine reaches operating temperature. Any and all input is greatly appreciated. Thanks
#18
02-14-2023, 09:20 PM
Post #12.
Problem solved!!! Luckily it wasn't a faulty torque converter or transmission or clogged oil port. I pulled my throttle body off today and it was packed with soot and grime. Took me almost an hour with a plastic brush and 2 full cans of throttle body cleaner to finally get it cleaned. Re-installed it, cleared the DTC’s and disconnected the battery for 5 minutes to clear active memory and took it for a long enough drive to get it up to operating temperature and to get the oil temperature at maximum and the RPMs remained steady in the 550-600 range without dropping. So after spending hundreds on new camshaft position sensors and VCT solenoids all I needed to do was spend $10 on throttle body cleaner and spend an hour cleaning it. Thank you to everyone who posted their 2 cents!
Last edited by glc; 02-14-2023 at 09:26 PM.