When I park my car at home, it's usually at a 10*- 15* angle or so. I noticed after I filled up my tank and parked it, later I saw a puddle in the dirt underneath the tank. I was dripping from where it had puddled on the heat shield/slpash shield area. I was thinking it might be coming from the filler neck but I don't know if its from there or on top of the tank. What's so weird, is that I can press the button on the gas cap and I can hear pressure releasing from the tank. What gives?

Ken

 

Might be one of the lines going into the fuel pump, on top of the tank.

 

There is a pressure relief valve attached to brake line, drivers side on the rear axle, if it gets to hot, or builds up to much pressure it can exit from this, broken filler neck, maybe someone drilled holes for an amp or something and punctured the gas tank, bad O ring on the fuel pump assembly. Check the lines for cracks, kinks to.

 

Would a possible leak at the fuel line(s) near the pump cause the car to idle kinda rough. Its not a real rough idle but you can tell it does'nt run smooth.

Ken

 

The tank holding pressure is normal.

For the leak check where the filler neck is connected to the tank. Many '91 & '92s have bad soldering on that connection. This allows fuel to leak. There is actually a GM recall on this. However, they didn't always make good on replacing the tank.

Can usually see the gas stains running down the side of the tank.

RBob.

 

I have an 89 Formula that also has the bad solder joint. After taking the tank out recently to replace the fuel pump. I neglected to fix the neck properly because it was 2AM and I forgot about it. bummer.

So, I was trying to seal it by reaching in there and applying "stuff" when all of a sudden the whole neck just spun and I was able to pull it through the filler door completely!

At first I was really bummed out, then it gave me an idea for the next time I have the tank out. I'll remove the neck, weld a collar on the neck (with gas tank *not* nearby), apply a gasket and a little rtv, drill holes in the collar and tank and use self tapping sheet metal screws to re-attach so it can be removed before dropping the tank next time.

For now, what I have done, is apply JBweld around the neck joint on the filler neck, carefully push it back in, then apply rtv around that, then support the neck around the filler door with foam material packed around it. It's holding for now.

 

The JB Weld will likely hold. However, RTV dissolves in gasoline.

RBob.