I'm getting ready to swap an FI engine into a '85 GS body, meaning the original engine was carbureted. My partner in this venture is concerned about fuel starvation, particularly in turns. So, this brings us to the question of: is there a difference in baffling between the first gen carbureted (GS) and first gen FI (GSL-SE) fuel tanks? And if so, does anyone have a GSL-SE fuel tank they'd want to part with?

 

IIRC the gas tanks for Carbed and EFI engins are the same

This is for the 84 & 85 models so, you should be ok

 

I haven reading that the two tanks are not the same inside...slosh shield and non-slosh. I have both but Im just lazy to investigate (both tanks are hanging in the garage ceiling)

 

I've checked out the parts feesh (How the **** to you spell that!). There are different TANK part numbers for 12a and 13b in 84 and 84.

SO 12a and 13b first gens HAVE DIFFERENT TANKS!!! The difference being the slosh shield.

Start building a surge tank, or looking for an SE tank, and in the mean time, stay above half a tank.

 

Thanks! If anyone has a GSL-SE tank they'd like to part with, PM me.

 

Fiche. Also, microfiche and microfilm are different somehow.

 

Microfilm is a roll I think, and microfiche is a sheet...


I think...

 

They are different. I'm doing the swap over on my current project. The pickup tube is larger and possibly the return line. It's been a couple of months since I looked.

Internally the is a cup at the bottom of the tank that the pickup sits in. This helps prevent fuel stavation as the return line fills the cup. There may be other baffling internally, not sure of that though.

When I picked up the GSL-SE tank, I also got the hard fuel lines, that way I can have an extra fuel line if I ever need to get fuel crazy.

Your other option would be a surge tank set-up, might be over kill for a basically stock set-up though.

 

Mine sucked bigtime, but I'm talking about the tank in my 82 GS....dunno about 84-85. What I can tell you is that fuel slosh was a HUGE problem for me after going FI. If I had less than 2/3 tank and I took turns hard at all, my fuel pressure would drop 15-20psi and the engine would stumble. I am happy to say that it was 100% eliminated by installing a surge tank and an additional fuel pump for it (I used my old carter). Here is the one I have:

http://www.tweakit.net/shop/product_...roducts_id=124

 

I think mazdatrix shows the same part number for 84-85 tanks for 13b or 12a. I thought the only difference was with the pickup? Would be different for 83 and earlier though, correct me if I'm wrong.

 

The tanks are different, so are the pick-ups.

 

yeah, your right, I just checked the mazdatrix site and they have two different part numbers now

 

SE tanks are definately different.The have the slosh box, the others do not since sucking a little air with a low pressure carb setup isnt a problem.
I also had big slosh problems below 1/2 tank.Usually on left turns.I took a different route which you might consider.Its less complicated than the surge tank and probably costs about the same in the end.
I chopped up an FC fuel tank and pillaged the slosh box and pump assembely from it.Any FC tank will work,any trim or year.
The pump assem. is the perfect height to fit into an FB tank.Just cut out the FB's hole to match the oval hole in the FC tank.Then have the mounting ring and slosh baffle welded/soldered into place by a competant shop.This setup has worked flawlessly for me and it exactly duplicates the factory FC setup.The pump is protected,silent and continually cooled inside the tank.Plus upgrading it is easy since FC,FD,Cosmo and SupraTT pumps are all a direct swap.Its very clean on the outside,with only 2 hoses and no extra tanks,plumbing or wiring needed.
The only catch was finding a shop willing to weld a gas tank.Obviously I thouroughly washed the inside out with soap and water beforehand,but I had to hit 3 places before finding a taker.Cost about $150 and took 2 days wait.Im glad I did though,because this setup really cant be beat for simplicity and reliability.

 

Excellent !!!!!!!!!!!

I had a similiar idea, but didn't pursue it. Now if I get tired of the 12abp, I can do the TII swap later down the road and not have to worry about fueling it.