Problems filling / P0453
 

Hi everyone,

I know both of these have been somewhat covered but I am at a loss here. I have been driving around for approx 2 months with a P0453 code. I only discovered this was the code about a week ago when I borrowed a friends OBD II reader. When I filled up my car about 2 weeks ago the pump kept shutting off. I blamed it on a faulty pump and continued to (painfully) fill the car. This afternoon I tried filling up again and it took me 5 min to get 2.5 gallons in the tank. Every time I squirted a little gas in it would back up (even when holding the nozzle partially out). I can see the fuel slowly draining down the fill hose. The fuel pump was replaced this past Feb. Ever since it was replaced I will get hard starts from time to time. If it doesn't start on the first ignition turn it always turns over on the 2nd. Any suggestions? I'm really lost here and I can't keep filling up this way!

There is a check ball with a spring inside the hose, right where the large fill hose attaches to the gas tank. Sounds to me like the ball is stuck in there somehow and preventing gas from entering the tank... probably happened when the pump was changed.
I would try to remove the hose and look up into it and see whats going on... if this proves to be difficult to do, you may have to drop the tank.

You have a valid point with the valve, however, I do not recall seeing this inside the fill hose. Wouldn't a check valve not allow you to siphon gas out of the tank?

Yes, that is correct. What year is your blazer?

Blazer is 2002

Yep, your Blazer has that check ball in there...

Would that code cause me issues trying to fill the tank?

If your EVAP system is actually seeing high pressure, sure. That would mean that your tank would be pressurizing for some reason..

Update on this in case anyone is curious:

I tore into the system this weekend and it appears that the Vapor Canister Purge Valve was stuck in the closed position. I removed the valve and applied 12 v. to the socket. I can hear the solenoid clicking but the plunger does not appear to move. I can manually move it back and forth. I moved it to the "open" position and put it back in service. I was able to fill up! I still have a trouble code but my thoughts are a new valve should resolve this. I'll post results after my junk yard visit.

One thought though...No power appears to close the valve while power opens it. When the car is off (and being filled up) wouldn't everyone have this pressure issue?