2004 Kia Optima trouble starting after filling up gas tank

For several years my husbands car “chugs” and barely starts after filling up at the gas station. Once it starts it is good to go but it takes many cranks and pumping of the peddle to get it going. If you put gas in it with a gas can it doesn’t have the problem so guess it may have to do with the pressure of gas going in from the pump?!. We have spent over 1500.00 when it first started to no avail…hoping someone has an idea. Very frustrating and embarassing!

Start by having the ECU scanned for any stored fault codes. You may not find any, but you might get lucky.

Does your husband “top off” the tank when he fills up? My guess is that it’s probably the evaporative emissions system. It could be that he’s getting fuel in through the vent line around the fill hole by “topping off” and when the purge valve is opening to pull in fumes from the charcoal canister during starting it’s pulling in fluid and flooding the engine.

For several years my husbands car “chugs” and barely starts after filling up at the gas station.

I’d leave it running while filling up. I always do.

Quoting @auto-owner “I’d leave it running while filling up. I always do”.

I wonder why they have those signs at all the gas pumps around here that say “NO SMOKING” and “TURN OFF ENGINE WHILE FILLING” ? Leaving it running with the gas cap off will often set a MIL code for evaporative emissions issues too.

“I’d leave it running while filling up. I always do.”

^
This is definitely BAD advice, and I hope that the OP ignores it.

For good advice, the OP should refer to the suggestion posted by the same mountainbike.

Thanks for the compliment, VDC.

I wanted to emphatically support the recommendation to NOT leave the engine running during fill up. While the rubber shrouds around the fill pipe combined with the vacuum being created at the pipe (NOT in the tank) by the gas going in make filling up far safer than in the '60s, all it takes is one spark at the right time to cause ignition of gas fumes. The National Fire Prevention Association recommends shutting off the engine, and some state laws mandate doing so, for good reasons.

The National Fire Prevention Association recommends shutting off the engine, and some state laws mandate doing so, for good reasons.

Yeah yeah, I hear you guys, and I figured I’d get jumped on for this, but I just hate shutting off an engine that’s going to be restarted in a few minutes, especially when it’s cold out. It’s just hard for me to see what scary thing is gonna happen just cause my motor is running. But then as a young guy I used to fill running motorcycles also (without incident), so maybe I’m just terminally reckless or something. Pardon me all over the place.

Thank you “The Same Mountainbike” for your comments. The problem occurs even if we just put 5 gallons in it so that eliminates the topping off issue (but he doesn’t do that either). Weird that it doesn’t do it if we add 5 gallons using a gas can but the “pressure” of using a gas pump causes it. We have tried leaving it running just to see if that would work and it choaks out unless you trickle the gas in (and who has time for that). I will ask my mechanic (who is baffled as well) about the codes and see what he thinks.

Try this, after filling the tank, get in the car and hold the gas pedal to the floor for about 30 seconds, then without lifting you foot off the gas, try to start it and see if it catches on the first turn, If it does, of course let up at that time and see if it idles ok.

I concur with your deduction that the pressure with which the gas is pumped from the pump must be a factor. Combine that clue with the symptoms, which suggest either flooding or fuel starvation after fill up, and I’ll suggest that it is possible that the pump’s pressurized stream is stirring up residue i the bottom of the tank that’s clogging the filter on the pump’s intake tube. It may be then setting again, allowing regular operation until the next fill.

The good news is that your car has a fuel tank service cover in the upper right hand corner of the trunk ledge. Remove the cover and unplug the pump, then run the engine until it dies. That’ll depressurize the line and allow you to ***** DISCONNECT THE BATTERY ****** and remove the pump assembly. Disconnecting the battery first is crucial to safety. Once the pump assembly is removed, you’ll be able to inspect the pickup tube screen and the bottom of the tank (with a flashlight) for…crappola!

Post back with your findings.

Could there be a blockage in the fuel filler tube? Something that causes, when under pressure, the fuel to back up and back up into the emissions system as @thesamemountainbike said in the first reply?
Perhaps a bent tube, or even some nefarious character trying to cause you issues?

Interesting theory, however if that were the case fuel would spill all over when gas is pumped.

Thanks guys! Out of town now but my husband is going to try these suggestions next week…will let you know how it goes! Thanks from SC!