Gas Tank Rumble

[MeShoHorny]

Got home today and when I shut the car down I could hear a loud rumble coming from the gas tank. I opened the gas cap and a lot of pressure released from the tank, followed by a stong smell of gas.
The fuel pump is pretty new (255lph) but I suspect the check valve. This was the 1st really hot (90 degrees) day that I have drove the SHO.
Can anyone give me some other suggestion on things I can check before I drop that tank? Also, could this be the retrun line as well? If so how hard/easy is it to replace....I am assuming I will have to drop the tank for this as well.
TIA,

 

[sdpatt]

The fuel return line check valve wearing out usually allows the fuel returning to the tank to vaporize and bubble up through the fuel while the fuel pump is running. I have never experienced it after shutting the engine off. Yes, you have to drop the tank to replace it since it is located at the end of return line below the fuel pump. Once you have the fuel pump and sender assembly out of the tank the check valve replacement is as simple as a hose clip. Here is the topic with the part number: http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=001478

 

[luigisho]

Jason, do your mods require the 255lph fuel pump? I ask because the stock setup with the usual bolt on mods neither requires nor can handle that flow rate. The symptoms sound like return problems. The check valve is at the end of the return line and could be the problem. With that much noise I'm just wondering if the system is overpressured due to return problems, pump overcapacity problems or both. I think there is a good chance the tank will come down again. wink

 

[MeShoHorny]

I'm gonna take the car for a spin and double check some things.

luigisho: No my car does not require a 255 pump but it did a few years ago.

When I replaced my pump on my 93 with a 190lph it came with the rubber check valve in the kit (looks like s ducks bill correct?)

I did a search and found a comment by pjtoledo but at this point I don't know if this applies yet.
http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=000369

 

[luigisho]

That's what it looks like (red duck call). I thought I had seen a few posts about not going over say 190lph for unmodified fuel system. Thanks for the link. The purge cannister sounds a lot easier to check first.

<small>[ April 17, 2002, 07:37 PM: Message edited by: luigisho ]</small>

 

[SHOMA]

I have a 95 MTX, am going through the EXACT SAME problem right now, if you look below the car, there are 3 lines running right by the fuel filter, slide the plastic covering down by hand, and there is 1 dead line....... It isnt a mechanical noise, it is the noise of fuel vapors exiting through a line that air should be going into.... I just replaced the fuel purge valve, that comes off of the carbon canister, (square piece, under airbox, mounted under fender), and the fuel vapors I believe have stopped, but I am still going to inspect the return and feed lines for a pinch... I also have a hesitation at LOW RPMs and slow startup after being run for the day, do you have those symptoms as well? I apologize for the extremly long post, but I know how hard it can be to trace the SHO problems.

95 MTX, flowmasters, 17" mille miglia rims, subs, amps.... More to come!
94 ATX (For Sale)
92 MTX (For Sale)
93 MTX parts car

 

[SHOMA]

sorry, I forgot to add, I can be emailed at [email protected]