Bootybandit Posted June 30 Share Posted June 30 After I replaced my holley with the Carter, I pulled the fuel sending unit to replace the float. I noticed a second cap on the gas tank that had a small hose connected to it running to nothing I assumed it was a vent for the tank (edit) Its running to a metal line that runs to nothing. I'm now experiencing what I think is vapor lock. Heat index is at 105 here in louisiana. After I get close to op temp I notice the clear fuel filter I bought has little no fuel in it and she go's kaput. 2 questions here. 1 does this sound like vapor lock? 2 is that little hose a vent or a return for vapor system with 3 nopple fuel filter? Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 30 Share Posted June 30 No, that doesn't sound like vapor lock. That would usually happen after you've driven far enough to get everything really hot. That sounds like you are pulling a vacuum on the tank. The little hose used to go to a vapor recovery cannister below the battery. But it sounds like it has been removed or disconnected. So the hose may be plugged. or pinched, which causes the pressure in the tank to drop down when the pump pulls some fuel out and eventually there's a vacuum that prevents fuel from flowing. You can check that by removing the fuel filler cap and driving the truck, although you might want to stick a rag in so no dirt gets in. Link to comment Share on other sites More sharing options...
mat in tn Posted June 30 Share Posted June 30 No, that doesn't sound like vapor lock. That would usually happen after you've driven far enough to get everything really hot. That sounds like you are pulling a vacuum on the tank. The little hose used to go to a vapor recovery cannister below the battery. But it sounds like it has been removed or disconnected. So the hose may be plugged. or pinched, which causes the pressure in the tank to drop down when the pump pulls some fuel out and eventually there's a vacuum that prevents fuel from flowing. You can check that by removing the fuel filler cap and driving the truck, although you might want to stick a rag in so no dirt gets in. just turn the cap to the unlatched point and leave it sitting in place. the seal will be relaxed enough. the small steel line that runs from the front may even be rusted closed. Link to comment Share on other sites More sharing options...
Bootybandit Posted June 30 Author Share Posted June 30 just turn the cap to the unlatched point and leave it sitting in place. the seal will be relaxed enough. the small steel line that runs from the front may even be rusted closed. Thanx guys I'll blow in the vent and see if its blocked. Link to comment Share on other sites More sharing options...
Bootybandit Posted June 30 Author Share Posted June 30 Thanx guys I'll blow in the vent and see if its blocked. Pulled the little booger and this is it. Internet says its a vent. After idling until it hits operating Temp I start to loose fuel in the filter it gargles until the filter is empty and off she go's. These are my guesses?? 1. Vapor lock 2. Fuel pump going out once it gets hot 3. Filter being aftermarket 4. Tank too close to empty (idk just guessing) Link to comment Share on other sites More sharing options...
mat in tn Posted July 1 Share Posted July 1 Pulled the little booger and this is it. Internet says its a vent. After idling until it hits operating Temp I start to loose fuel in the filter it gargles until the filter is empty and off she go's. These are my guesses?? 1. Vapor lock 2. Fuel pump going out once it gets hot 3. Filter being aftermarket 4. Tank too close to empty (idk just guessing) I think it's time to test the fuel pump. Link to comment Share on other sites More sharing options...
dirtymac Posted July 1 Share Posted July 1 We're from Louisiana as well. Last Summer I thought we were experiencing vapor lock in our truck. We had just gotten it and the heat was about like it is now. I was certain it was vapor lock. We ended up having a bad fuel filter Obviously, you have a clear filter so that's not it. I will add that any kind of opening on a vehicle is fair game to mud dauber and wasps this time of year. I've pulled two off the truck in the last week. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 1 Share Posted July 1 We're from Louisiana as well. Last Summer I thought we were experiencing vapor lock in our truck. We had just gotten it and the heat was about like it is now. I was certain it was vapor lock. We ended up having a bad fuel filter Obviously, you have a clear filter so that's not it. I will add that any kind of opening on a vehicle is fair game to mud dauber and wasps this time of year. I've pulled two off the truck in the last week. I was going to say mud dauber. It's also not uncommon to find them in the axle vent, and people think they have bad hub seals... It could well be crap in the tank has the pickup 'sock' all jammed up. You could try putting another 5 gallons in and blowing back through the fuel line to dislodge any rust or varnish deposits. The rollover valve needs to equalize pressure so the tank doesn't see vacuum. I've run a piece of tygon fuel line from the check valve up the filler tube, terminating in a Toyota/Lexus transmission vent that is up above the filler pocket of the bed. This setup seems to work fine for me, but I live north of NYC, and certainly don't experience gulf coast heat. ETA: Is your Bronco the 2 barrel electronic or the 351H.O. 4V? Link to comment Share on other sites More sharing options...
dirtymac Posted July 1 Share Posted July 1 I was going to say mud dauber. It's also not uncommon to find them in the axle vent, and people think they have bad hub seals... It could well be crap in the tank has the pickup 'sock' all jammed up. You could try putting another 5 gallons in and blowing back through the fuel line to dislodge any rust or varnish deposits. The rollover valve needs to equalize pressure so the tank doesn't see vacuum. I've run a piece of tygon fuel line from the check valve up the filler tube, terminating in a Toyota/Lexus transmission vent that is up above the filler pocket of the bed. This setup seems to work fine for me, but I live north of NYC, and certainly don't experience gulf coast heat. ETA: Is your Bronco the 2 barrel electronic or the 351H.O. 4V? We had the door to our washroom open yesterday for about 6 hours while we were working on the truck. That was long enough for a dauber to build an entire nest. I had no idea they could work that fast. He got evicted :) Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 1 Share Posted July 1 We had the door to our washroom open yesterday for about 6 hours while we were working on the truck. That was long enough for a dauber to build an entire nest. I had no idea they could work that fast. He got evicted :) Bees and their kind are very industrious, hence "busy as a bee" You should see wasps and hornets build paper nests! Link to comment Share on other sites More sharing options...
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