Megasquirt EFI and Ignition Project

[81xsproject]

Bad new; today's testing revealed that the wonderfully small LTR fuel pump is just that, too small. For all the sceptics out there, you were right. I borrowed a friend's fuel injection pressure gauge and plumbed it in. WOT at 5-6, the pressure started dropping off, and by 7+, the pressure had dropped to the mid-high 20's. Looks like it's back to the drawing board for a fuel pump

[Thee_oddball]

i just got done reading this post and i really like the idea of FI, Is this a fuel pump you could use? there is a graph at the bottom of the page that shows
Fuel Pump Performance Curve Chart

http://cgi.ebay.com/ebaymotors/89-94-Nissan-240SX-Walbro-Fuel-Pump-255LPH-S13-SR20DET_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1240Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1309Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem4a97ade0e8QQitemZ320372334824QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[81xsproject]

Well, you may have just read it, but you missed some details. The challenge with the fuel pump, is finding something small (but in my case not too small), low current draw, and most of all, INLINE. Thanks for the link, but that pump, like nearly all motorcycle pumps, is in-TANK.

[cowboybob998]

Dont know if this will help but I was reading on a gold wing site last night and the were talking about elect. fule pumps for the old gold wings that have a mech. fule pump, any way some guy come up with an idea of useing a vacume pump like the ones on snow mobiles, would this do you any good ?

[Montreux_Blue]

Go to your local auto parts store and see if they can find you a cheap small car inline fuel pump, something like an 84-85 RX-7 GSL-SE that had a fuel injected 1300cc with inline fuel pump. Or even a junkyard if you want a cheap one to experiment with.

[Thee_oddball]

is this closer?

http://cgi.ebay.com/ebaymotors/Walbro-110-lph-inline-GSL395-Fuel-Pump-12V-2-15psi_W0QQitemZ300314354671QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item45ec2163ef&_trksid=p4506.c0.m245&_trkparms=72%3A1171|65%3A12|39%3A1|240%3A1318

[DiverRay]

is this closer?
http://cgi.ebay.com/ebaymotors/Walbr...3A1|240%3A1318

That only goes to 15 psi. EFI systems need about 34 to 45 psi......

[Shappers]

Sorry to hear about the pump not working out, hopefully you will come up with something else.

I was thinking that if I did mine again I would make a small fuel tank the same size as the battery and then fit a Suzuki in-tank pump to the end of it. I would then relocate the battery.

It would solve the return line to the tank problem, getting fuel from both sides of the tank when nearly empty and the in-tank pumps are cheap(er) and plentiful.

I had a nightmare tying to find a place for my external pump, in the end there was only 1 place and in 1 orientation where it would fit. Compact is not the word

[Thee_oddball]

That only goes to 15 psi. EFI systems need about 34 to 45 psi......

ahhhh ..thnx

[Guy_b_g]

You might want to check this one out...seems reasonably small...specs are good...looks easy to mount...don't know about current draw.

Trick Flow inline fuel pump:

Free Flow Rate 43 gph
Inlet Attachment Hose barb
Inlet Quantity Single
Inlet Size 5/16 in.
Maximum Pressure (psi) 85 psi
Outlet Attachment Hose barb
Outlet Quantity Single
Outlet Size 5/16 in.
Quantity Sold individually.

$84.95

ebay#220405387775

[Guy_b_g]

Here is a picture of how the Weber-Marrelli fuel pump on my Guzzi was mounted.

http://i430.photobucket.com/albums/qq26/guy_b_g/dscf0011-1.jpg

The fuel line came from the left side of the tank, ran under the backbone of the frame and down to the pump, then back up to the backbone and to the left side of the tank, where it went into a regulator/return flow fitting in the place where a second petcock would be, and the main line split off to the fuel injection (also a Weber/Marelli system). You shouldn't need all the extra plumbing unless you planned to make the tank airtight.

Perhaps there is room for the same type of installation higher up on our bikes if you use the area near the front of the valve cover where the horns on some models go?...just a thought.

By the way the fuel pump on the Guzzi was stock, but I added the custom made mount with cooling fins.

[Guy_b_g]

Correction to last post...the return/output line went to the right side of the tank, not back to the left side....oops

[clcorbin]

81xsproject,

What fuel pump did you finally end up going with? I'm pushing forwards to converting my 79 over and that pump issue is DEFINITELY the biggest hurdle!

[81xsproject]

Sorry, I didn't get back to your question, sooner. I don't know how I didn't see it. Anyways, I am currently running the elusive 99-00 Busa pump like Shappers. This winter, I will be trying out the inline MSD pump as part of getting the airbox back in. For a real project update, I ordered an PMW idle valve from one of the old 3 cylinder Geo Metros (1000cc). With the addition of brainless engine starting (no choke, levers, cables, idle screw adjustment, or throttle use) I will finally have ALL the conveniences of modern EFI. The unit is very small, and I intend to mount it in the airbox between #2&3 intake boots. I will run the 'out' into a vacuum line to the intakes. Then I will have to do some testing and tuning.

[natemoen]

Man I love this idea. It just everything it takes to get it done that makes me not want to do it.