Weird issue when filling up..

[musthunt]

I have noticed this problem / issue on my 2000 Catera almost every time I fill up with fuel.
When I attempt to restart the engine after filling up, (no top off) the engine is very hard to start, and usually dies from low idle, only idiot light to come on is the "gas cap" light.
2nd attempt to start usually results in a rough lower than normal idle which slowly ramps up to the normal "warm engine" low idle.
The gas cap is tight, gasket is still pliable, number of clicks dont matter after the first one, because the clicking is the internal over-tightening preventer releasing, so 1 click or 20 clicks the gas cap is just as tight.
What could possibly be causing this to happen?

[CateraMV6]

If we think logically through this, the only thing that happens when you fill up is your fuel tank level changes... the only thing in your fuel tank is a sending unit and a fuel pump... so I bet it has something to do with your fuel pump...

Maybe have someone check the fuel pressure when you turn the ignition on... then with the engine running ... then try opening and closing the gas cap and recheck the fuel pressure again... I am not sure what but maybe your fuel pump messes up somewhere in this picture and causes your issues...

Thats certainly the first time I have ever hard of this type of problem too..

[investor74]

Maybe the problem is unrelated to filling up and is a more general warm-start issue. Can it happen after stopping the engine for a few minutes and re-starting?

Have you scanned the on board computer for any codes? That might point you to the problem.

Barry

[1998catera151]

I am new to these cars but I have had simular problems with other cars and had to replace the gas cap, and make sure you get the one made for this car. hope this helps and if not you can return it, lol

[musthunt]

As if the problem wasn't weird enough as it was, let me expand on it a little bit.
I've remembered that almost everytime the fuel tank gets below 1/4 tank I have the hard start issue along with a poor / low idle problem. You can 2 foot it and keep it running no problem, but if you have to stop quickly or it dies the only idiot light that comes on is the stupid fuel cap light.
Does anyone have the part number for the fuel cap, if so I'll see if I can find a deal on one.
They shoud've called this car the Cadillac 200, cause every time I go to get parts it starts at $200.