F.I. fuel tank.

D

DazUK

Cheers Daz
Is there any difference between the injection fuel tank and the carbed tank. Reason I ask is if I decide to go injected, will I need to convert the tank so as to prevent any air intake during 'spirited' driving, or can I make some kind of 'swirl pot' like the carb float chamber, but which holds more fuel.
Or more simply, do I just make sure my tank never gets below quarter full.
I'm worried regarding forced induction and lean mixtures if the pump cavitates etc...?
 
An FI tank feedsthe fuel pump form the bottom engine side

a carb tank feeds the fuel thru the tank sending unit from the top of the tank.. A carb tank does not have the bottom engine side of the tank. I say you need a FI tank......
 
With my Uno Turbo conversion I originally used a modified carb tank pickup. I removed the skinny little carb return pipe, opened up the hole in the sender unit plate and inserted a length of 8 mm copper pipe to make the FI feed. I shortened the carb feed pipe and used it for the FI return. I mounted the pump off the engine lid hinge. This seemed to work fine, but I wasn't entirely happy with only an 8 mm feed pipe and the pump having to draw a suction head equal to the height of the tank. I wanted to have an in-tank pump, but the Bosch pumps I had at the time were too big to fit through the sender unit hole and I didn't fancy cutting open the tank. Latterly I have made a US FI style outlet in the bottom of the tank, using a brass cistern fitting and a bit of 15 mm copper pipe from B&Q. The FI pump is mounted roughly where the US FI pump goes, using a made up bracket.

I have since found that there are FI pumps that will go in the tank and will fit through the sender unit hole. I think the in-tank FI pump from a Seicento Sporting would fit the bill for instance. An in-tank pump is what I would do now if I were starting from scratch.
 
In my Uno T conversion I used the original carbed tank together with the UT pump (most likely the very similar to FI X pump).
I mounted the pump below the tank to be sure that I had some pressure acting on the pump.

I have had to renew the pump after a couple of years but had to do with poor standard of the original pump in the first place.
I wanted to see that the concept worked before investing any money in good pump.

And no, I've had no problems with fuel supply even though I've been pushing it through corners.
 
I have a spare carbed tank in the loft I could perhaps modify for a bottom mounted pump ... will cistern type fittings cut it tho' or would brazing on a medium (15mm) supply pipe be a better route.
 
I wouldn't bother

My Uno Turbo conversion uses a standard carb tank. The fuel pump is mounted on the side of the engine bay at the top. The conversion was done in the early nineties and I have never had a problem. Last year I converted a second car to FI and used the same setup also with no problems.

Still I do wonder why the Fiat engineers felt the need to make the change. Maybe it was in the Bosch FI installation instructions
 
It seems I remember

reading some time ago it was mounted low, to prime the pump quicker.Also the pump is not suppossed to run dry as it cools it, so it won't burn out.

Perhaps it's meant to push and not actually pump(suck the fuel). I'm certainly far from an expert on this however. so ???
 
Yes, it sucks...

At sucking. The F.I. pump is meant for pushing and creating pressure. Not very good at sucking or overcoming head pressure in the long run.

And yes, the stock pump is lubed and cooled by the very fuel it pumps. Run it out of fuel and you could burn it up.

The F.I. tank features a large outlet near the bottom, which comes out of an area in the tank bottom that is baffled to prevent fuel from sloshing away from the outlet.
 
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