Strange Fuel Leak Engine Bay

[atvjoey]

So guys, I recently bought an 87 TBI r10 and I got the occasional whiff of raw gasoline from time to time but I always figured it was from running no o2 sensor since the previous owner did headers without the proper o2 ****. Well today I was in a parking lot and I ran in real quick to grab some food and I left the truck on, it had about a half tank of gas in it at the time. When I came out, there was gas all over the parking lot ground coming from my truck. I found the culprit hose but I am not sure where the hose is supposed to connect to or how to prevent this problem in the future. I believe it's part of the charcoal filter hoses but I am not sure since the truck never had one since I got it. It looks to be plugged with electrical tape. If anybody has any ideas on what it is, where its supposed to go, or how to eliminate this problem that would be much appreciated. Pics are below, the hose in question is the one zip tied to the brake lines to get me home with the least amount of spillage possible.

 

[atvjoey]

here are the pics

 

[Bextreme04]

So guys, I recently bought an 87 TBI r10 and I got the occasional whiff of raw gasoline from time to time but I always figured it was from running no o2 sensor since the previous owner did headers without the proper o2 ****. Well today I was in a parking lot and I ran in real quick to grab some food and I left the truck on, it had about a half tank of gas in it at the time. When I came out, there was gas all over the parking lot ground coming from my truck. I found the culprit hose but I am not sure where the hose is supposed to connect to or how to prevent this problem in the future. I believe it's part of the charcoal filter hoses but I am not sure since the truck never had one since I got it. It looks to be plugged with electrical tape. If anybody has any ideas on what it is, where its supposed to go, or how to eliminate this problem that would be much appreciated. Pics are below, the hose in question is the one zip tied to the brake lines to get me home with the least amount of spillage possible.

You need to actually insert the pics in your post. When you "Attach Files" of pics, they will show up on the post window, but you will need to click on them and select to insert them into the body of the post also.

 

[atvjoey]

You need to actually insert the pics in your post. When you "Attach Files" of pics, they will show up on the post window, but you will need to click on them and select to insert them into the body of the post also.

Sorry my bad, now it says waiting for moderator approval so I am thinking it should take a few minutes

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[gmbellew]

sounds like the tank may be being pressurized.

 

[Bextreme04]

Agreed, the TBI sending unit for a Suburban/Blazer type tank should have 4 fittings on it. One is for the filler tube vent. Then you have fuel feed and return. Last one is tank vent. The tank vent line either has a wobble check valve similar to your diff vent for non-emissions vehicles, or it runs up to the charcoal canister like yours.

Without having that hooked up or plugged off, fuel vapor can be condensing at low points in the line or filling up with fuel when you fill the tank up. Then when it gets hot and the fuel in the tank expands it blows all the liquid in the lines out. The normal system would be running through a charcoal canister and then into a manifold vacuum port on the carburetor to actively pull the vapor out of the tank and keep it from getting clogged or filled up like that.

I would suggest you either restore the entire system to the way it is supposed to be(install charcoal canister to that hose and then line from other port on canister to the throttle body vacuum port), or disconnect the vent line from the tank and install a short check valve to prevent water intrusion while still allowing it to vent.

I also highly recommend you install the O2 sensor. Fuel injection doesn't work well without correct O2 sensor data. You can install the sensor with nothing more than a step drill bit and about 20 minutes of your time. Welding in an O2 **** is obviously the best, but they make bungs that can be installed with no welding required. Just make sure you get the correct one for the diameter of your exhaust.

Glowshift, fitech, and hooker all make decent quality ones. https://www.ebay.com/itm/372543346917

 

[atvjoey]

Agreed, the TBI sending unit for a Suburban/Blazer type tank should have 4 fittings on it. One is for the filler tube vent. Then you have fuel feed and return. Last one is tank vent. The tank vent line either has a wobble check valve similar to your diff vent for non-emissions vehicles, or it runs up to the charcoal canister like yours.

Without having that hooked up or plugged off, fuel vapor can be condensing at low points in the line or filling up with fuel when you fill the tank up. Then when it gets hot and the fuel in the tank expands it blows all the liquid in the lines out. The normal system would be running through a charcoal canister and then into a manifold vacuum port on the carburetor to actively pull the vapor out of the tank and keep it from getting clogged or filled up like that.

I would suggest you either restore the entire system to the way it is supposed to be(install charcoal canister to that hose and then line from other port on canister to the throttle body vacuum port), or disconnect the vent line from the tank and install a short check valve to prevent water intrusion while still allowing it to vent.

I also highly recommend you install the O2 sensor. Fuel injection doesn't work well without correct O2 sensor data. You can install the sensor with nothing more than a step drill bit and about 20 minutes of your time. Welding in an O2 **** is obviously the best, but they make bungs that can be installed with no welding required. Just make sure you get the correct one for the diameter of your exhaust.

Glowshift, fitech, and hooker all make decent quality ones. https://www.ebay.com/itm/372543346917

Yeah I've been trying to work on putting in an o2 sensor since my check engine light is always on bu I don't have a welder. I'll look into that clamp style for sure. Probably won't restore it to the filter since I'm not really sure how it's supposed to work and the added cash right now for the parts is also a bit of a problem. Short term is there any quick fix, I know this isn't the best question to ask but right now this is my only "working" vehicle so I need it back on the road asap

 

[Turbo4whl]

........ Short term is there any quick fix, I know this isn't the best question to ask but right now this is my only "working" vehicle so I need it back on the road asap

Joe, @Bextreme04 gave you the best quick fix. Stop a salvage yard and get the charcoal can. Two vacuum lines and you are done. You need to have the vent for the engine to run.

 

[atvjoey]

I was more hoping for a fix along the lines of limp it to an advanced auto parts. The nearest junkyard for me is about 3hrs away and they have no squarebody's. As I said this is my only car as my other car is apart for a fuel pump/regulator/lines job so is there a way to prevent it from spewing gas out as a temporary fix until I can get the parts? Maybe driving without a fuel tank cap? Also, unless I am missing something, shouldn't gas not be just pouring into the charcoal filter? If this was connected wouldn't it just dump gas into the canister? It seems that would be a bandaid to the original problem of gas tank pressure. Please explain it to me if I am not understanding correctly.

 

[Turbo4whl]

Assuming that this only happened once while idling there may not be another problem. The line being plugged have stored a fair amount of fuel and the pressure in the tank push open the taped end of the hose.

Plug the line with a bolt And a clamp see if the truck stays running and if you build pressure in the tank. If this works you can drive to get the canister

 

[Bextreme04]

I was more hoping for a fix along the lines of limp it to an advanced auto parts. The nearest junkyard for me is about 3hrs away and they have no squarebody's. As I said this is my only car as my other car is apart for a fuel pump/regulator/lines job so is there a way to prevent it from spewing gas out as a temporary fix until I can get the parts? Maybe driving without a fuel tank cap? Also, unless I am missing something, shouldn't gas not be just pouring into the charcoal filter? If this was connected wouldn't it just dump gas into the canister? It seems that would be a bandaid to the original problem of gas tank pressure. Please explain it to me if I am not understanding correctly.

Its not the cheap fix, but it is the quick one. Go down to the local parts store and buy a new canister. The ports will be labeled, plug the one from the tank into the one labeled "tank" and buy the right sized emissions hose to run up to the plugged port on your TBI.

https://www.oreillyauto.com/detail/...evrolet-r10-pickup-rwd?q=vapor+canister&pos=0

 

[Raider L]

Excellent advice. I can just see it now "flames in the parking lot". Now, I didn't put out any negative vibes but just the image, no name, no put on.