2007 Kia Rio not starting...diagnostic reads lean on MAFS?

[Kevin Sloan]

My friend has a 2007 Kia Rio 5. Last night, his car was driven to a friend's house and he stopped it there for about 20 minutes. Following this, he went to start his car and the engine refused to turn over. I used my OBDII scanner and it was throwing a lean A/F ratio. I cleaned his MAFS and throttle body, but it still refuses to turn over the engine. YES, there is gas in the car. My suspicion is that the fuel pump may be failing. It is not an issue with the battery or the starter, as the starter turns the engine just fine. The engine will not ignite and turn over. Anyone have any idea?

[bobweb]

Spray starting fluid into the throttle body or air intake duct. Crank the engine and if it fires up immediately and then stalls, you'll know your on the right track thinking it's a fuel problem. Otherwise, you'll want to check for good spark. Don't forget the car has a 100,000 mile 10 year powertrain warranty and an emissions warranty that may still be in effect from Kia. If it has spark plug wires, try the spark tester below. Listen for the fuel pump to run for a few seconds when you first turn the key to "on" (not "start"). Cycle the key on 5 seconds, off 10 seconds to make the pump run and listen for it at the gas filler (cap removed). Check the owner's manual and reset the red fuel pump bypass switch if it has one. The computer may require good spark detected before it will allow the fuel pump to run continuously.

https://napaonline.com/Catalog/CatalogItemDetail.aspx?R=SME705931_0215388768