98 v70 NA P0455 - my most loyal friend

[98v70dad]

My loyal friend just showed up P0440. I just replaced the Purge Valve with Pierburgh brand.
All these loyal friends can wait because the EVAP issue is not urgent.
Too cold now to play with it.
I told my loyal friends to leave my house and I will talk to them in April, when the weather is warmer.

We have smog testing in Atlanta and you can't renew your registration without proof of passing. So, I don't really have the luxury of waiting. The clock is ticking. At least I don't live in Chicago anymore, it was about 60 degrees here on Saturday. That's just cold enough to keep my beer chilled while crawling around under the car. Its a little colder now but still not too bad.

[kahl]

I went to the Dealership and got the scedmatics for my evap system. The number 8 digit in the VIN number indicates what system is in your car. Mine was the number "4". There are three electrically operated valves 1. Pressure sensor around the gas tank filler tube 2. Purge valve on the upper battery side of the radiator 3. Shut off valve inside the fender behind the plastic wheel liner by the A pillar. The EVAP canister is under the battery accessed from below, there are two "U" shaped hoses that are prone to cracking. So far I have changed the two "U" shaped hoses, replaced a defective purge valve and the two hoses by the rollover valve. This weekend I am changing the shut off valve with a serviceable valve and inspect the hoses (again) in the engine compartment and around the fuel tank. Here are some pictures of the three major area of the EVAP system on this car.

[kahl]

Here is a picture of the vent valve in the left fender. With no power it is open. When 12 volts DC is applied it closes with a thunk sound. Part number is 9135805.

[Thunderbox]

Thanks for the pics. My setup is in the rear of the vehicle. Can anybody tell me if the vent valve pictured above is located near the fuel filter and the canister under the right rear? Or is it hidden up near the tank?

[abscate]

It's a different setup if you have the later EVAP system in rear. Different components too.

[98v70dad]

The latest post here made me think abut reading some older threads again and I noticed that someone said that topping up the tank after the gas pump shuts off will cause damage to the EVAP system. rspi also mentioned it in one of his videos. I drive a long way to work and could get away with one fill up a week if I squeezed in an extra gallon so I routinely did that for years before I knew better.

What gets damaged by topping off the tank? That may be the solution to my mystery since I've replaced nearly everything else.

[abscate]

Raw fuel into the rollover, purge valve and evap canister perhaps?

[Thunderbox]

It's a different setup if you have the later EVAP system in rear. Different components too.

So any idea what the pressure sensor looks like and where it is for my setup?

[98v70dad]

Raw fuel into the rollover, purge valve and evap canister perhaps?

\

The evap canister and purge valve are way up front on my car ... about 10 feet away, although I suppose you could suck liquid fuel that far. I haven 't had it off to look at but I would guess the rollover valve is nothing more than a check valve that shuts off due to gravity if the car is upside down. It isn't electrically actuated and is only called into action by rolling the car over onto its roof (I think) so fuel doesnt leak out of the vent line and ignite. I recently replaced the purge valve a few months ago and there was no evidence of liquid fuel in the lines.

I have no idea how the pressure sensor works. Does anyone know how that part detects the pressure? If it supposed to be in fuel vapor but instead is bathed in fuel due to over filling I could see how that would kill it eventually. Any other comments on what overfilling damages would really be appreciated.

[abscate]

Later models ( maybe my ME7 car?) have a pressure pump which works on the tank and tests it for integrity. The earlier cars use the purge valve and close the cutoff valve to put vacuum on the tank then test to see how fast it comes back up to atmosphere. If the system does not behave your friend P 0455 is set.