IngSoc

I have a 1st gen 4 runner and it smells like gas really bad most the time. I dont see any leaks and it smells like its coming from the charcole canister. When I open my gas tank there is a positive pressure and most of what ive read from searching most people have a vacume. Suggestions?

James Woods

iTrader: (1)

If you top your tank off, it will cause the fuel when it expands to flood your canister, then when your canister tries to vent, it will smell like raw fuel really bad and the tank will not be able to breath correctly giving you excessive positive pressure. I would check the canister and make sure it is not filled with fuel.

scope103

You should NEVER have "vacuum" in the fuel tank. If you did, you couldn't pump fuel out of it, so the vented fuel cap allows air into the tank. But when it warms up the fuel evaporates and increases pressure in the tank. The fuel cap doesn't vent that direction, so you should have a little pressure in the tank pretty much all of the time.

The canister collects those fumes to keep them out of the air. If you flooded the canister, you'll definitely get a gas smell. But those fumes leave the canister into the throttle body once the engine warms up (pulling through the TVV). The TVV is fragile and many of us have broken it; if its broken you get no vacuum on the canister and the fumes eventually leak out.

Terrys87

iTrader: (1)

Check and see if the return line on the firewall isnt plugged up. I have seen that line clogged. The "J" line on the fuel pump bracket tends to get clogged as well and am wondering if the pressure from not returning back to the tank is causing it to smell some.

I take an air hose and with the gas cap off, you can hear the tank bubble.

Here is the plugged line I was talking about.


This "J" line likes to get clogged. Check all of them, but most likely this one will be clogged.

IngSoc

Thanks for the replys. This is my ...... 6th? toyota and each time something a little different. My last 1st gen 4runner had the lines crossed at the tank and was draining fuel from my canister. This kinda reminds me of the same thing but no fuel out of the bottom of the canister. I will try the air trick and purge out the lines and I figure while im at it change the filter. When I come home at night I can smell my truck from my room (20ft) My gas mileage is TERRIBLE. Thanks for the replys thus far.

IngSoc

So went out side to tinker for minute and this is what I came up with.
This guy is connected to the bottom the the "Dampener?" When I pull it off it squirts fuel. And from what I gather on my other trucks, it dose that.

This is the dampener/ regulator? I notice the idle go up and smoooth out a bit when I pulled hose. I have a question about this a little later.

Now these guys.... 3 plugs, The one in the middle left kind of has a plug that reminds me of an injector but not white? not sure what the one with the briaded loom does and hove no clue where the (knock sensor?) wire is.

The small vacuum hose on the cainister is going here on the throttle body. I pulled all the lines and felt no vacuum any where.

And this guy is self explanatory.

Terrys87

iTrader: (1)

On your 2nd picture, I think it is called a regulator, that is how I check to see if it is getting good fuel flow and it eventually goes back to the tank. If I recall right, the line goes to the inner fender on passenger side. That is where I had the (in my first picture above) gear fluid bottle cap to use as a funnel and poured Marvel Mystry Oil in mine to break up the rust.

Another way I check to see if it getting guel flow to the rail is to loosen the Cold Start Injector feed line and it will spray fuel out fast. Just thought I would add that for info.

On your 3rd picture, the red sensor, that is your Oil Sender Unit. It has a broken wire on it. For some reason, Toyota made another little wire about 4 inches long that connects to the wire that is laying on your blue wire harness. Grab one out of a boneyard and you will be able to hook up your Oil Sending unit again.

I cant see your Knock Sensor, but it is a white plug near your fuel filter.

I cant recall what the green connector goes to right off. Might be to your IACV Valve, located just up above the AC compressor area.

Also on your 3rd picture, it easily forgotten, that black/dusty rod is to be bolted to the bottom of the Plenum, it is there for support.

On your 4th picture, I would double check and make sure all of your vacuum lines are hooked up correctly. Not sure where a good diagram is at. I have three 22res and always make sure I have one for a reference. Vacuum may not be present on all of them and the hose connections coming off of the Plenum can be plugged with carbon caused by the EGR.

I have run into this several times which isnt related to your fuel pressure but could make you think you dont have vacuum.

Here both the port and line is completely plugged with carbon. There were others plugged as well.