Ford F550 6.8 Surge
We just replaced the left exhaust manifold on this truck. We had to disconnect the battery to do some welding for stud removal. Since hooking the battery back and running the engine we get a wide RPM surge at idle. We suspected that we had lost the adaptive memory for idle so we cleaned the throttle body and reset the KAM. We are still getting a surge but not as bad. There are no codes stored. If we look at scan data the only abnormal item we see is O2 Bank 1 Sensor 1 Status -Fault. Is there an idle learn procedure that we're not seeing or can anyone think of something we are overlooking?
For some reason whenever I try to fill out the VIN or symptoms box, whatever I have typed in disappears when I click send or save changes. Sorry.
Here is the VIN:
Whats the loop status, fuel trims and o2 sensor data saying at idle, and have you driven it or just in the bay testing? Also does it smooth out just off of idle?
Hi Brian, Thanks for the reply. I just went out and ran the truck again so I could get some data. This time the engine idled smooth, both before and after the road test. RPM's are steady @ 730, STFT's are around 0, LTFT's are around -9, although they were higher and came down the more I ran the truck. The system went into closed loop. I think we just didn't give it enough time after resetting…
This one is fixed. I'm pretty sure the original surge was caused by losing the memory from unhooking the battery. After cleaning the throttle body the surge was better but not completely gone. After another drive cycle the surge was gone. I think we just didn't give it enough time. Thanks for the help.
It would be nice to edit you post like Tom said, this way if someone else needed to look this up under the vehicle they are having problems with its there to help them. Thanks and have a great day.
Hi LaMont, The VIN wasn't able to be decoded for some reason, thus no vehicle was filled in. However if you type the year model and engine size into that field, you should see some suggested vehicles that you can choose from to tag your post. I've tagged your vehicle based on the model year encoded in the VIN, but feel free to edit and adjust it if needed. In terms of the symptoms box, can you…