View Full Version : True fuel level in tank..

01-18-2006, 04:17 PM
As I read, I see that our tanks hold 1-2 gallons in the bottom even after being run 'till your car shuts off. (from the octane rating page)
The quick solution to draining ones' tank of pump gas, so that you can throw some race gas in there, is via this little kit I seen, that you attach to your fuel rails, and pump it out through there. Well, how does that work, if it's using your stock fuel system then? (basing this off of the fact that, I just got done reading, that there's still a gallon or two in the tank, 'cuz the sending unit doesn't reach all the way down to the bottom.)
Is there any ready-made kits, that utilize a hose that you run down your filler tube, and initiate an external pump, so that ALLL of your previous gas AND little rust sediments can get sucked out that way?
When I drain my tank, I want ALLLL its contents out. Anyone else do this?

01-19-2006, 08:46 PM
FWIW, I have not seen anything that does not attach to your fuel rail to drain the tank. I tried the old siphone once but to not much success.

01-20-2006, 12:02 AM
Lovely idea, but it just won't happen.

With the baffle in the tank, even a hose won't get to the bottom and get it all out. Probably the only way is to remove it and sop it all up with towels, then let it sit out so the rest evaporates. The baffle will not let the hose get to the bottom. Won't even let the pump strainer get to the real bottom of the tank. Just the bottom of the baffle. I've had my tank open at least 3 times. Maybe I'll take some pictures next time. We need and illustrated pump install guide for the site. I'll probably have it down again in the spring. But other people are more than willing to contribute as well.

If you drain it right, there is probably less than a gallon in there. I'd say a lot less. I've been doing manual fuel changes for almost 15 years now, and I think I've done it enough to be comfortable with the process. I know there is some grit in my tank. But between the strainer and filter, it generally can't get through. Plus, each injector has a screen in it. So rest easy. And complain to your local filling station about the cleanliness of their fuel. And get a filtered funnel if you want to be ultra-careful about things.

01-20-2006, 04:40 AM
Ahh I see. Darn. Well I'm going to drop my tank here shortly. If you'd like, I can take all sorts of little pictures and whatnot. I'll show the old fuel pump/sending unit, and the replacement of the new one too. And all the little baffles if you guys' would like.

01-20-2006, 10:23 AM
Sure...we can build a pump install writeup. (Credited to you, of course.)

The baffle isn't that small, you'll soon find...

01-21-2006, 12:13 AM
Darn, I just replaced my fuel pump on my 86' GN just this past Tuesday, I wish I would have know. I could have taken several photos. I was lucky because my pump still worked. I placed a hose on my fuel rail and connected 12v to the grey connector behind the alternator and pumped the fuel out through the fuel rail. As I found there is really no way to drain the tank completely, I even tried turning it upside down to drain the remaining fuel out of the nozzle with no luck. The plastic baffle surrounds the pump like a bucket and the bottom of the baffle doesn't go all the way to the bottom of the tank. I'm not sure how to get ever drop out. Seemed to be about 1 gallon left in the tank.

01-23-2006, 05:16 AM
I see. Aw well, I'll just clean the heck out of it the best way I know how while it's down. I'll just throw a good amount of decent gas in her, shake it up, and keep bumping it 'till I get most of it out, along with some of the sediment I know is down there. She'll be clean one way or the other.

01-23-2006, 10:17 AM
Not to get too off topic, but do any of the aftermarket gas tanks have that baffle in there? From what I've read, that is a unique design. I will eventually have to get a new tank because mine is rusting under the straps and actually leaking a tiny bit. I know I could patch it, but that to me seems like only a temporary fix.

01-23-2006, 11:49 AM
do any of the aftermarket gas tanks have that baffle in there?
Not that I am aware of. There is a tank that most places carry, made in Canada, and it has either no baffling or very insufficient baffling.

Might want to look into getting yours patched professionally.