Any gas tank experts here?

[TYTILIDIE]

Ive been having some odd fuel issues and I need to find someone who KNOWS this stuff. My main problem is htat I lose fuel pressure on hot days. Yesturday was in the 90*s and I drove around all day in the heat and did fine. I got home at about 4pm. My wife got in at about 5:30pm. We went to my moms house to watch a movie and before we got out of our parking lot, hte truck tried to bog down and die. Luckily I was able to limp it up the hill back to the garage. We took her car and got back around 9pm. Took the truck out and it was fine. This has happened to me 5 times now. One day, about two to three weeks ago I was at the gas station and left the truck running. I went to take off the gas cap and watched the FP gauge on the pilar and it dropped to 35 then 20 and then stalled out. I thoguht to myself that I wonder if this problem is related somehow. I put the cap back on after I filled up and hte truck seemed ok, I didnt continue what I was doing and booked home before I got myself starnded. Now, I took the cap off of my wifes TY and put it on mine. Since then, on hot days like yesturday and today, after drving I can listen to the cap and you can hear boiling or bubbling or something. I took the cap off and the spray was incredible. It lasted for almost 30 seconds with the cap totally off. What the hell is going on here? When I put my toher caap on, I dont hear anythign but does hiss for about 20 seconds. Does anyone here know enough about tanks and caps to tell what could be happening?

 

[Daryl H]

Re: Any gas tank experts here?

It lasted for almost 30 seconds with the cap totally off. What the hell is going on here? When I put my toher caap on, I dont hear anythign but does hiss for about 20 seconds. Does anyone here know enough about tanks and caps to tell what could be happening?

Was the truck running at the time?

My only thought would be to check the Evaporative Emission Canister.
Maybe it is full of fuel or a check valve is bad somewhere allowing boost to get caught in the system. Could be sucking fuel right into the intake?

 

[QWERTYphoon]

Re: Any gas tank experts here?

ok, my first guess is: There is a check valve hooked up between your intake and vacuum canister?
Bad gas cap and/or filler spout?

 

[gjp]

Re: Any gas tank experts here?

my truck did that too a while back. for about a month on real hot days. I thought it was the canister. I removed it but it looked ok. Reinstalled and put on a new gas cap. I t has not done it since. not sure why it was doing that. It did the exact same thing yours is. thinking maybe the vac line was pinched into the canister?? dont know if it was the new cap?

 

[TYTILIDIE]

Re: Any gas tank experts here?

Cap is fairly new but I will buy another one to be sure. I tossed the canister years ago though. I have the port on tank for that plugged off. Its been that way for about 3 years now, maybe 4 actually. I did that the same eyar I bought hte truck.