2006 Ford F-150 Lariat 5.4L V8 Triton Flex Fuel 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

 

Here is a quick update with where I am at. I replaced both of the Camshaft Position Sensors with a good improvement in how the engine runs and a major reduction of the amount of valve ticking the engine is known for. Unfortunately no luck with the RPM issue tho. Then I went and replaced both of the VCT Sensors, this showed major improvement on how the engine runs and the remaining valve tick has been completely eliminated. One thing I noted while replacing the VCT Solenoids was that on one of them the screens on the bottom portion of the solenoid were gone and are presumably in my engine somewhere. I am hoping that since they were made of a fragile plastic and a very small metal screen that my engine chewed them up and caught them in the oil filter. If it didn't then I am wondering if they may be still inside the engine and clogging up an oil port somewhere causing my issue. Any input and ideas are greatly appreciated. Thanks.

 

i've seen a few cars and trucks that were stalling when stopping come into the shop. 2 cases we found the issue was in the auto transmission with the lockup clutches inside the convector sticking/staying on,when they should be released , sadly that means a costly overhaul

 

Are you talking about a possible issue with the Torque Converter? I have read a few things stating that is a possible issue but I have been hoping that wasn't the case. At this point with the amount of miles my truck has on it that would mean I have to get rid of it. I am going to try a few more things to fix the issue. I am going to clean out the throttle body and if it doesnt work I am going to check the IAC sensor and the TPS sensor. If none of that works I will bring to a mechanic to be diagnosed. I read a post about a truck with the same issue and this guy just cleaned his throttle body and put a new oil filter on and the problem went away. I appreciate the input.

 

YES!! we rebuild tranies and have seen where in high mile rigs there was metal filings that got into the valve body, clutch packs and converters causing the packs to stick on when they should have released that caused stalling on deceleration
i would do as you state make sure there are no underlying issues first than have a transmission shop test drive it ,

 

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!