Replacing Gas Tank in my e30 with a "newer" late model tank

so I'm completely stumped at this point, having re-built lots of e30's i've never run in to this mod (if you could call it that) Anyone familiar with doing a early---> late model tank swap and or how to re-route the hoses, I can figure out the wiring of the senders and such. But the big thing that I need help with is re routing the hoses. Any help would be great! Thanks in advance

I thought it was a drop in, the only major difference being that the later models had an internal connection for the tanks vs the early model "fuel starvation pipe" connecting left/right.
But I could be wrong, check the specE30 folks.

Ooh, ooh, pick me. I did the swap (along with 2 fuel pumps) on my E30. It's been 6 years, but I think I remember it.

The later tank takes up the space of the stock external fuel pump. You'll need to remove it and bend the bracket out of the way.

You need to swap your pre-pump to a later pump that's designed to be used alone. You can put your pre-pump in the second fuel pickup location in the later tank, then plumb them to a T for better fuel pickup.

The vent line goes to the vent on the tank IIRC.

The return line goes to the new fitting on the new pump, instead of the fitting that used to be on the early tank. The later tank has no return fitting.

i have 2 cars an 86 and 90 the 90 has a siphon pump in the second location already with a new pump so i was thinking i would just use that setup Im just completely confused by the expansion tank and the return lines. The reason being that my old tank had 2 pumps right, so the in tank pump LP pump if you will, or transfer pump, had a out feed and a return feed the new pump doesn't. so I need to just run the return line into the tank (side where the little pipe is near the passenger wheel? sorry this might seem confusing, but I'm over trying to figure it out, there aren't any good write ups on the issue, but i know people do it all the time.

Thanks for the help Though, that helped a lot actually. :P

The old return line went into a fitting on the tank. The new tank does not have a return fitting, instead the return fitting is built into the later in-tank pump. Connect your return line there.

Does that help?

Timeormoney wrote: I thought it was a drop in, the only major difference being that the later models had an internal connection for the tanks vs the early model "fuel starvation pipe" connecting left/right. But I could be wrong, check the specE30 folks.

they are pretty close to the same, one has two connections on the top of the transfer pump and the "new in tank" pump only has one return hose coming off it. other than that very similar.