kcarty

Hello.
I brought my 2005 Tahoe Z71 to a local shop to check the "check engine light" and the strong odor of gas. He said it was a small evap leak and suggested I replace the gas cap. I did, and that didn't work. I searched this forum a bit and found that the evap vent solenoid is a common problem. So, I swapped that out as well. Still having the gas odor and the gas tank wont fill unless I fill it 20 cents at a time! Does anyone have any suggestions? I appreciate any feedback as I don't want to go to a shop and spend a fortune. I also don't want to just swap out all the parts in my evap system.

Thanks.

tech2

what was the dtc that set?

kcarty

I'm not quite sure. All he told me was that it was an evap leak and that it was probably the gas cap.

tech2

When refueling, the air in the tank vents out the vent line from the tank to the canister, to the vent solenoid out to a fresh air pipe. If restricted the air can't get out creating a positive pressure that inhibits filling. The restriction could be any where along that series of parts I've named.

Without and diagnostic equipment to test anything; I would start disconnecting from the outermost part of the vent line and try filling the tank to see if it fills normally.

A blocked vent line will set a different code than a evap leak code; but you would not smell fuel unless the cannister is completely saturated with fuel.

kcarty

Thanks. This gives me an idea on where to look. If the gas odor would indicate a saturated canister, could a saturated canister block the venting of the tank?

kcarty

Also, I seem to be some kind of issue with starting. When I start the truck after it has sat for a while, it cranks for a long time and doesn't start on that crank. The next crank always starts it right up. I feel quite confident that these problems are connected somehow.

tech2

more to the story eh!

the long crank may be due to a bad fuel pump check valve or a internal/ external fuel leak. You can confirm this by priming the fuel system before starting.

Cycle the key from off to run, the fuel pump will run for 2 seconds. After the 2 seconds turn the key to off. Repeat 4x then start the truck. Does it start normally/quickly now?

The better way to do this is with a fuel pressure gauge. Prime the system then let it sit and watch for pressure drop.

DPLarson

Yes it could. When one of my other vehicles wouldn't take gas I ran it almost to empty and then let it sit for two weeks without ever starting it during that time. Ever since it takes gas as usual.

kcarty

I imagine the fuel pump check valve would be part of the pump itself. Is this correct? If so, the tank will need to be dropped and that is too big a job to do in the driveway. Sounds like I will need to take it somewhere. Could even be a fuel leak due to the odor, but I'm not sure how that would be causing the problem with filling the tank. I wonder if there are several issues going on at once.

in2pro

If you are handy capable the fuel pump and dropping the tank is not hard, its bulky and requires getting the vehicle up on jack stands but its doable in a few hours... I've got 3 of them under my belt...