external fuel pump - fuel injection

[petejw]

i know it was a while back but i remember
a few ppl were looking for a cheap fuel
pump for when they were messing around
with fuel injection, found this on the
hayabusa site,

http://www.ebay.com.au/itm/ws/eBayIS...#ht_586wt_1393

thought i post it up for any1 that might be after 1 in the future.

[Prothec]

I'm starting to acquire parts to Megasquirt my in-progress '78 rebuild.

I was looking at the Hayabusa pump diagram. I would still need to locate the assembly this goes into in order to use it, right?

Looking through lots of forum posts and discussion on EFI, it seems some have talked about making a secondary tank to use an in-tank pump, but I have not found any information about anyone who has been successful going that route.

Anyone happen to have any experience with a secondary tank?

[650mark]

fuel pump

don't know if this info applies to your situation but, fwiw, when the oem electric fuel pump on my carburated '86 gl1200 went south i didn't feel like giving honda $175 for a new one. i found a neat little pump at napa auto that worked perfectly, fit right into the stock external bracket, was rated at 1-4 psi, and cost $49.95. took about 15 minutes to wire it in and worked great for thousands of miles. they had others on the shelf that are higher rated for fuel injection as well. perhaps one would work for your application.....?

[jjz28]

FI sounds pretty cool. Why couldnt the pump just go in the tank or an inline electric pump? I am sure there are a lot of variables that i dont even understand about fi but it sure sounds interesting.

[Prothec]

The ideal pump would likely be around these specs:
43 PSI
90 - 100 LPH

I have searched all over for an inline pump with those approximate specs, but haven't been able to find one. I had planned on this TRE Performance pump, until I realized it is an in-tank pump:

http://www.ebay.com/itm/330512652614...84.m1423.l2649

If I can find an inline pump with an acceptable pressure rating, does it matter if the flow rate is higher?

[jjz28]

i know it doesnt on cars because you just get a fuel pressure regulator and turn it up or down to where you need it to be. Actually, you can dial it in exact with a fuel pressure regulator, so i would probably put one on anyway. you could get one that flows more than what you need and turn it down.

[Prothec]

Ahh, that makes sense.

I suppose these would be viable options as well:

http://www.ebay.com/itm/Fuel-Pump-Va...efed41&vxp=mtr
$80

http://www.fuelpumps.com/19821984-pe...-p-102892.html
$50

Obviously a major further consideration is the maximum current draw.

This page has a table of specs for the Walbro in-tank pumps:

http://www.autoperformanceengineerin...l/fpspecs.html

Considering the charging system puts out ~24 amps, I definitely need to keep an eye on that or consider the mini-Alt mod.

[Prothec]

I e-mailed TREperformance to ask about max current draw on the TRE-507 pump and they replied "The max would usually be around 9-10 amps".

Everything that I've looked up so far has shown around 5 to 6 amps under normal operating conditions for similar pumps. I'm thinking I will definitely need to add up all of the lights and switch everything I can out for LEDs.

I'm probably going to need to keep looking to try to find something from another bike/quad.

[crazy steve]

...Looking through lots of forum posts and discussion on EFI, it seems some have talked about making a secondary tank to use an in-tank pump, but I have not found any information about anyone who has been successful going that route...

If I were trying this, a secondary tank looks like the best solution. In-line pumps aren't that common any more (and even less so on bikes) as nearly all manufacturers have gone to in-tank pumps for several reasons; better cooling, less chances of leaks, physical protection. I'd look for a similar-displacement bike with EFI and get the pump and it's mounting flange off the tank. You would have to fab a tank and figure out where to put it; in place of the tool box is the first place I'd look.

That leaves the problem of pump current draw and the wimpy XS charging system. It's hard to find electrical specs on these pumps, but if you look for pumps OEM to bikes, checking the charging system specs for the specific bike would give you a pretty good idea. 'Basic' electrical loads on 'naked' bikes (not your optioned-out touring models) should be roughly the same (headlight, tail, ignition, etc) so if the donor bike system is close to the XS in terms of output, chances are good that the XS system could power it. You still may have to drop some load with LEDs to get there. I'd look at sport bikes and Harley Sportsters to start with. One advantage to the Harley units would be that HD doesn't change designs that often, so sheer number of possible used units will be in your favor. Plus at some point, the aftermarket will step in with lower-cost units, something you rarely see with import bikes.

This may not be the cheapest route, but sometimes there isn't a cheap way...

[CaptonZap]

If I can intrude with an observation, when FI pumps return unused fuel from the rail to the tank, the temperature is increased a little bit. After a while, it can raise the temperature of the fuel in the tank.
For that reason, I would not run the return line to the header tank, since it would get hotter much quicker due to the small volume. Run it to the main tank.
We now return you to your regularly scheduled program. CZ

[hamjam]

CaptonZap... said

"If I can intrude with an observation, when FI pumps return unused fuel from the rail to the tank, the temperature is increased a little bit. After a while, it can raise the temperature of the fuel in the tank."

what is the temperature rise in this application?
tia
Jim

[natemoen]

The pump itself gets hot and the fuel absorbs that heat. Also the compression and expansion of the fuel also creates heat.

[DGXSER]

Pumping any fluid will increase its temperature. The pump itself, (not the motor, but the impellor) will has friction on it moving the fluid so heat is developed, moving the fluid through a pipe adds heat due to friction, when the fluid in this case fuel reaches the rail close to the engine, depending what material the rail is made of and how the rail is insulated if ti is, the fuel will pickup the heat of the engine it is close to.

How much heat, well, that is an interesting question, one I do not feel like calculating out. If it helps think of it this way though, ever fill your tank plum full then park your biek with the engine hot? Come back to see some of the fuel oozing out your gas cap? That is because the heat of the engine heated up the fuel and what little air is in your tank expanding it to push it out the only hole available. The fuel injection process will not add that much heat to it.