Strange Fuel Issue After Every Refuel

[fiveohfour]

Details on the car:
2JZGTE VVTI swap / 550cc's + OEM Supra TT Resistor Pack / AEM EMS v2 Dezod / Single Walbro 255


Description of Issue: After every refuel (I usually go from Full to 2 gallons left) upon restart, the car will require throttle response to start - when it starts, its running hella rich and requires throttle response to stay alive. After a little while, or if I apply some load and drive it on the street for 20ft or so it clears up and goes back to normal.

Is this a vacuum related issue or is my gas tank not properly ventilating the air, increasing the pressure in the tank, and consequently the pressure in the lines??

[-Tom-]

Evap issues. Guaranteed.

If you know someone else with an IS try and switch out Evap purge valves with them.

[fiveohfour]

Ah damn, maybe I should weld a nipple to my intake pipe and reconnect my EVAP vacuum line? Boost Logic told me it wasn't needed, and did not connect it during the rebuild.

[jasonm4]

I'm going to have to go with Tom here. Sounds like your vent valve or either the vapor pressure sensor isn't doing it's job or purge valve, as Tom said, is stuck. Usually if it's the vent valve, you'd have trouble filling up as it would stop the pump every few seconds. I'm not familiar with an EVAP line delete that's functional.

[fiveohfour]

Originally Posted by jasonm4444

I'm going to have to go with Tom here. Sounds like your vent valve or either the vapor pressure sensor isn't doing it's job or purge valve, as Tom said, is stuck. Usually if it's the vent valve, you'd have trouble filling up as it would stop the pump every few seconds. I'm not familiar with an EVAP line delete that's functional.

Thanks for the response. Actually on one occasion the car would not pump more than a second or two - I didn't know what piece was responsible but I knew it was related to venting the pressure in the tank.

I've had the car back since January, put roughly 6000 miles on it so far. Out of all of those fill-ups, I've only had one incident where the vent valve wouldn't allow refuel. Every other time, however, the fuel/AFRs gave me the originally-stated problem.

[PEndl303]

Happens to me all the time with the pumping issue

[jasonm4]

Originally Posted by PEndl303

Happens to me all the time with the pumping issue

Your problem sounds like the vent valve. Check out this similar thread that includes part number.
Fill-up Issue..

Originally Posted by fiveohfour

Thanks for the response. Actually on one occasion the car would not pump more than a second or two - I didn't know what piece was responsible but I knew it was related to venting the pressure in the tank.

I've had the car back since January, put roughly 6000 miles on it so far. Out of all of those fill-ups, I've only had one incident where the vent valve wouldn't allow refuel. Every other time, however, the fuel/AFRs gave me the originally-stated problem.

I have a feeling it is either your purge valve by the intake is sticking or your vapor pressure sensor is stuck and not telling the pressure switching valve to keep tank pressures balanced. Do you have a CEL? Above I posted a similar thread as well and turned out to be vacuum switching valve. Hope this helps..

[fiveohfour]

No CEL. Dezod AEM EMS v2.

Much appreciated. I will diagnose it this weekend.

[Jerm__]

^Shouldn't you always have a CEL with the EMS V2?

[Twitched1]

visually no, but if you scan, you will have codes.

[Asteriks]

i have same problem. i solved it to blocked the hose witch come on intake.. no problem enymore