I have an '02 Ranger, 4.0, Auto transmission with about 150k miles on it. Recently the check engine and fuel cap lights came on and I took it to Ford to have them fix it. Ultimately, they ended up replacing a portion of the recirc tubing from the fuel system that had rotted. I also let them give the truck a tune up where they replaced the spark plugs, etc.

Since then, it's been having difficulty with cold starts. I have to give it gas and hold the pedal down. The issue seems worse on cold mornings than during the day. The engine will surge some during this time. I have no problems at all with starting it when the engine is warm or after it's been started for even just a few minutes. Currently there are no idiot lights on, and no codes on the truck. It runs fine.

Does anyone have any thoughts on what could be the issue? Thanks.