Gas cap issue? (1 Viewer)

[kevine]

I recently posted that I had a bad gas smell in the cab of my '84 FJ60. I figured it out...gas was leaking from one of the hoses coming out of my fuel pump. My buddy and I thought it was due to the aftermarket gas cap that I bought when I had to have it smogged. So, I ordered an OEM cap based on my VIN number. I put it on at the dealership, and on the way home, I stop for gas. When I take the new OEM cap off, I hear a big "whoosh" of air." Not good.

When I get home, I take it off again, a small "whoosh" and I notice gas gurgling down from where the fill is, and the rubber ring on the cap is wet from gas.

Not sure if it's the charcoal canister (hope not, they're expensive), or some other issue. Any suggestions?

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[Rock Cruiser]

1/2 problems solved?

well i get the same whoosh of air because its a suction system so you will get that.


for the wet on the gas cap idk....

 

[gregnash]

There is some venting going on in your tank that is the Whoosh sound. It has been determined (mostly) that the whoosh/venting is due to the life of your charcoal canister being at it's usable end. The charcoal canister is inside the engine bay, right side by the starter.

Basically, the charcoal acts as an absorbent for fuel vapor from the tank allowing it to then slowly dissipate with some fuel remaining in the charcoal. However, over the years the ability of the charcoal to absorb the vapor becomes less effect and thus it builds in the tank. This is the resulting WHOOSH when you open the cap. Looks like it is time to replace your canister, but the OEM is NLA (if I remember correctly) and there is no direct replacement.

However, all is not lost, there is a thread in the 80s forum that has an alternative from a GM vehicle that will work (VC-120 I think is the part number from autozone). Many have had great success with it and there is only a small amount of modification needed to the mounting bracket to hold it.

 

[kevine]

thank you!

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[SteamerF18]

There is also troubleshooting for the charcoal canister on 3-8 of the Emissions FSM, you can try that first. I followed that procedure and the back pressure that is released when I pop off the gas cap has been reduced. I expect I'll be doing the GM retrofit that Greg pointed out once my canister gives up the ghost. HTH.

Scott

 

[dozerking]

a small whoops is normal but a rellay big whoops is bad! has to have something to do with your charcoal canister! my bother had a BIG whoosh one time after a motor change we stoppped to get gas i heard the whoos and told him something was wrong he said he would look at it next day his truck burnt to the ground!! get it fixed asap!!!!

 

[kevine]

I got a big whoosh...looks like I'll be taking it out and cleaning it out. I found the post with the emissions page showing how to clean. As soon as I get to a computer, I'll post it here, but it sounds pretty easy. I'll try that first, and if not, start shopping for the GM alternative. Thanks.

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[Texasknowhow]

I'm getting a very long whooshing sound as I spin off my gas cap on my '96 80S. You guys think it's the same issue?To me, it seems like pressure not suction.

 

[Trapper50cal]

Rochester Charcoal Canister available at AutoZone, etc. around $45 bucks (IIRC), new vented gas cap from Mr. T (Cdan - American Toyota of ABQ)

 

[Trapper50cal]

I'm getting a very long whooshing sound as I spin off my gas cap on my '96 80S. You guys think it's the same issue?To me, it seems like pressure not suction.

It is pressure, air is displacing gas, air is escaping, gas is replacing space air is evacuating. It's also hot liquid gas in some instances and is boiling off as vapor when air is allowed to escape.

 

[kevine]

Rochester Charcoal Canister available at AutoZone, etc. around $45 bucks (IIRC), new vented gas cap from Mr. T (Cdan - American Toyota of ABQ)

If I have a brand new OEM vented gas cap, do I need another one? I'll go to AutoZone this weekend and pick up the new charcoal canister, after I've removed the current one. I want to take the old one with me to compare size and hose fittings.

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[Trapper50cal]

If I have a brand new OEM vented gas cap, do I need another one? I'll go to AutoZone this weekend and pick up the new charcoal canister, after I've removed the current one. I want to take the old one with me to compare size and hose fittings.

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No, you should be fine with the one you have...

You know what? I got my tech sections mixed up, I thought I was in 80's tech...the 80 series is the one that the Rochester replacement will fit in.

My bad entirely - I don't know of a cheaper 60 series-based replacement.

 

[Spike Strip]

You can do one of three things, or all three if you like:

1) - Vented gas cap. Toyo part 77310-60090, like I posted in your other thread.

2) Switch the hoses on the Charcoal can to bypass the one-way valve inside the can

3) Buy a new canister, or the aftermarket version for about $40, that works (search).

I guess there's a fourth: Try cleaning (blowing) out the charcoal can as shown in the Emissions FSM. Sometimes that works, but I've never had much luck with it.

 

[krustaceon]

So, can the whooshing issue potentially cause spontaneous combustion? I'm getting whooshing also with a new OEM gas cap. I guess the focus for me will switch from radiator flush to charcoal canister rehab.

 

[krustaceon]

oh and one more question....will a bad charcoal canister affect the performance of the carb? because i think the canister is connected with/to the float? I've been getting a small fuel leak somewhere from the carb and its happening slowly after the engine is turned off. the following morning there is a gassy odour and moisture from gas around the carburetor. wonder if the venting problem is connected to my carb performance...

 

[Trapper50cal]

So, can the whooshing issue potentially cause spontaneous combustion? I'm getting whooshing also with a new OEM gas cap. I guess the focus for me will switch from radiator flush to charcoal canister rehab.

No, not spontaneous combustion (I don't think) I just wouldn't fire up a smoke while near the gas filler when it's doing it'd fume/vapor-based version of a blow dryer.

 

[kevine]

I had a leak from a hose coming out of my fuel pump. I replaced the cracked hose. Amazing the damn thing didnt catch fire. i also got the OEM gas cap and I'm going to remove my canister this weekend. I'll clean it then take it somewhere to see if there is an alternative canister (I've read there's a GM one that might work). If the cleaning works, then at least I'll have a spare once the whooshing sound returns.

 

[kevine]

So I removed my charcoal canister, and I've blown air through the thing, like the manual shows (plug tank and purge lines, and put 43 psi through the top tube [carb i think]). I used a little more than 43 psi, and i can definitely smell fuel coming out the bottom, but that's about it. Not sure if this is going to be enough to avoid having to do this every few months. Regardless, I'm looking online for a compatible vapor canister/charcoal canister. The problem I'm finding, most have two lines (tank/purge) or at most, three lines (tank/purge/carb). The one that comes with the FJ60 has four, tank/purge/carb on top, then a bottom line that goes into a metal tube that goes into the frame, which I believe is the return line going back to the gas tank.

Can anyone confirm this for me? And can anyone say whether this line can be plugged, or have you seen a charcoal canister with a similar four lines/tubes?

 

[kevine]

Okay, I've looked online and went to every auto parts shop everywhere and no one can give me any advice regarding a compatible charcoal canister to replace mine with. So I followed the directions in the emissions manual, plugged the tank and purge lines, and hit the carb inlet with my compressor. I tried it at about 50 psi (manual says 43), and it didn't really seem to be doing anything. I cranked my compressor up to about 100, hit it with small bursts yesterday and today. Re-installed, and the whoosh sound is gone!!! Took about 30 mins.

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[Jlosquared]

Man I'm so glad I found your thread,I'm in over a hundred bucks on cap, seals and new lines and still smells like gas inside. I'm gonna borrow a compressor from a buddy and give this a try.