My car 2008 car has 150,000 miles. Whenever, I try to start the car after I fill the gasoline, it gives me problem. The only way, I can start the car is either when, I have to pump the gas or keep the gas paddle down, while I am trying to start. Initially, I thought the issue is time related and the car does that when its stopped for short time. I got great response from the community who proposed that it maybe leaky injectors. After hearing from them, I started keeping the track of time it takes before I can start the car without any issue and then I realized that its not time related but only happens, when I go to the pump. Thanks
That new information suggests an EVAP system problem.
Have you checked the ECU for stored fault codes?
Do you “top off” the gas tank when you fill up?
1 Like
I will get the codes checked. Yes, I always fill the gas till the tank is completely full. Thanks.
That practice may be your problem’s root cause.
When your tank is filled with gas, it still needs to be able to breath. It does so through an activated charcoal bed in it’s “breathing tubes” (NOT the technical term, my own for the purposes of explanation) through which it must breath. The charcoal captures hydrocarbon molecules to prevent them from escaping.
On some systems, repeated “topping off” the tank can enable raw gas to flow into the tubes and saturate the charcoal bed. Most modern systems have valves to prevent this, but your symptoms fit the disease. That chokes the tank off, preventing breathing, and the vacuum that develops when the pump starts up can prevent the pump from feeding sufficient fuel to the engine. It can even overstress the pump and cause premature failure, 'cause the pump has to struggle to breath in, fighting vacuum in the tank.
Post the codes. I would expect EVAP system codes for this.
Whether or not you have EVAP codes, and whether or not this turns out to ultimately be the problem, I recommend that you change your practices to removing the pump nozzle when it clicks off rather than “topping off” the tank.
Just a bit of added trivea; “activated” charcoal only means chunks of charcoal that have been soaked in acid to make them highly porous. It’s the surface area that matters, and highly porous chunks have far more surface area per volume than solid chunks.
You might try seeing if it will start reliably after you temporarily loosen the gas cap. Just as a test, don’t drive the car that way. It could be a vacuum is forming that prevents gasoline from leaving the gas tank.
Thanks Guys
This time when I filled gas, I didn’t top it off and temporarily loosen the gas cap. However, I faced the same problem. Any suggestions ?
Have someone check the residual fuel pressure as the problem might be caused by vapor lock.
Vapor lock occurs when the hot engine is shut off and the gas in the fuel rail(s) starts to boil making it hard to get the hot engine to start and run.
What’s suppose to happen is, when the hot engine is shut off, the anti-drain back valve in the fuel pump holds residual pressure in the fuel system. This prevents the gas from boiling which prevents the vapor lock.
If a pressure gauge is connected to the fuel system, and then the ignition switch is turned on to run the fuel pump, the gauge should hold the residual fuel pressure and then slowly bleed down over time. If the gauge shows fuel pressure and then the gauge immediately drops to zero when the fuel pump stops running, the anti-drain back valve isn’t holding the residual fuel pressure and vapor lock occurs.
Tester
This is a bad purge valve. You can get a genuine Hyundai purge valve for about $25 on Amazon. Note: You must replace it with a genuine Hyundai purge valve or the error code and symptoms will return. (This is bc generic purge valves don’t have the right electrical impedance for Hyundai vehicles.)
1 Like
OP is probably no longer reviewing these comments, but I expect FunkyCat (aka @sherrie.g5_185593) is correct, maybe OP will post back with the exact cause , who knows?
The explanation: During refueling, to make room in the tank for more fuel, fuel vapor is pushed into the canister, which holds onto the fuel component, and lets the cleaned air pass through into the atmosphere. For this to occur correctly the purge valve must be closed. If the purge valve is faulty & open during refueling, the fuel vapor will go directly into the engine, making the fuel/air mixture too rich for a successful warm start.
Can’t speak to the electrical impedance issue, but seems pretty likely the car’s electronics does require all of the solenoid resistances to meet the expected specification for coil resistance.