High RPM off of cold start and Low RPM after refuel.

[Mr FiSTer]

New to the forum just looking for some advice. I just bought a 2017 FiST and off of a cold start RPM will sit around 1200 for about 10 to 15 seconds and then it will lower to about 1000 for about 5 minutes until the engine warms up then it will finally drop down to about 750. Also after refueling the car on idles it will drop down to 500 and then shoot back up to 800. I already took out the throttle body and cleaned it, it doesn't look damaged in any way. This did not help at all. Need some advice on what could potentially be the issue.

 

[WannabeST]

The idle for 10-15 seconds sounds pretty normal in most cars tbh. I wouldn't be worried about it in my opinion. If it was closer to 2k rpm I would be worried. However the low rpm after refueling is because the evap purge valves suck in these cars. If you top off the car or don't leave the gas pump in for a while after it finishes it will likely go bad. I've seen many people have to replace them every 30-50k. I just replaced mine at 35k. Some people get a CEL, and other don't. It's like $40 from autozone and a 2 minute swap. Yours is likely on it's way out. After I changed mine it doesn't have low idle after fueling. I leave the pump in for around 30-60 seconds after it stops. I clean the windshield to kill the time.

 

[kazoospec]

The "high idle" at start is normal. It will likely last longer with colder ambient temps. The "post fill up" issue is likely the purge valve as Wannabe says. There's a page and a half of discussion here: https://www.fiestastforum.com/threads/evap-purge-valve-assembly.30792/

I'm still under warranty, so I'm going to make Ford fix it for now. I'll mess with it myself once it's out of warranty.

 

[XR650R]

Welcome!