Trouble starting when RE starting

Kia amanti 04

It’s getting worse where when I try to start the car AFTER starting the car later in the day (not a fresh start it always starts up, it’s when I try to start it AFTER the fresh start)

I have some codes and I took It for a smoke test and the shop told me I had a leak in my filler neck.

Now, I’m also being told by other people it could be a bunch of other things and I don’t want to spend hundreds on a filler neck if I don’t need one.

My codes are, p0456 , p0431, p0442. And OCCASIONALLY I get a p0157, and that seemed to stick around once I got a new flex pipe put in.

Can someone PLEASE tell me where to start before I put money into stuff I don’t need. Sometimes when I start the car, the rpm idle is really low for a few seconds (while I’m trying to start it) then jumps to normal for the whole ride once it actually starts. It seems like a fuel or air problem. I’m not savvy when It comes to cars but I also look for different opinions before I dump money into something.

To re iterate, the only problem seems to be when I start the car the 2nd or 3rd time of the day, and some even days it’s doesn’t even happen! But when it does, the car hesitates to start and the idle is SUPER low when The car is TRYING to start, but once it starts, it’s fine.

Any feed back helps

If the engine starts normally with the accelerator pedal pressed slightly, clean the throttle body.

There is a hole in the filler neck, how could you not need a new one?

1 Like

I looked up all the codes.

And none have anything to do with restarting the engine once it gets warm.

But one thing can cause an engine from restarting once it gets warm is bad crank sensor.


@Nevada_545 I mean that’s thats they hinted at… they can be wrong right? I noticed a hissing sound under the engine bay but apparently I’m crazy because they don’t hear it

@Tester do you know if those are easy to replace? I see the part is cheap and wouldn’t mind doing it myself

@Nevada_545 Haven’t had to. It normally starts up. But today it took a whole, I’d say, 4 in a half seconds, and that’s a record for the past year or two it’s been doing this. I’m quite familiar on holding the pedal if it takes longer, but I haven’t had to, YET

The leaking fuel filler tube is causing P0442 and P0456 faults but not the starting problem. If you feel that fuel leaks are normal then you don’t need to repair it.

Leave for work 4 seconds earlier.

I get the sense fuel is leaking into the engine somehow when the engine is off. This would explain the starts ok when cold, but hard to start hot, as too much fuel is helpful when starting a cold engine (remember the days of the choke?), but too much fuel will prevent a hot engine from starting. A leaking fuel injector could cause such a thing. A fuel pressure hold test might provide a clue. Make sure to do the test to determine the engine computer knows the correct coolant temperature too. If the computer thinks the coolant is cold, it will double pulse the injectors, and this symptom could result.