Fuel system conversion..Carb to FI

[Susanoo]

Ive got an 89 dx and I've been planning this project for a while. Recently I've been trying to get everything I need ordered and ready for the engine swap that'll be following the fuel system conversion. My current idea involves AN stainless steel line going from sending unit to the firewall, through a bulkhead connector, to an AN line fuel filter, finally to the fuel rail. I have the FI fuel pump that I pulled from a hatchback LXI. The only problem is how to connect the AN line to the stock sending unit and fuel rail. I was looking at using NPT to AN adapters, but I'll be honest, I don't know for sure what Honda uses. I think what they use is called a bonjo? And Jegs makes a banjo to AN adapter but it's apparently intended for use on the aftermarket carbs they sell. No idea if that will work for connecting to the sending unit. I know that two people on this board have done this conversion. One is named like carrotman or something and the other is like 87roach. Hopefully they jump into this and give their ideas.

[ShyBoyCA6]

if they done the conversion like you posted on here then you need to search under their names to find some info. Good luck.:nervous:

[Susanoo]

Well that's why I posted this...I can't find info on HOW they did it. That's how I found 87roach's project thread. I searched for carrotman or w/e it is..the user is also an admin here and he's published how to's...but nothing that I have found about the conversion. I spent 2 hours on this site the other night trying to find info on it.

[Dr_Snooz]

Welcome to the board! You probably want to take a gander at this.:
http://carotman.no-ip.com:8888/personal_site/howto/eficonversion/conversion.html

If you still have questions, post them up.

[A18A]

that's cause people who do the conversion use a factory fuel line instead of running their own one like this guy wants to. sorry i can't help

woops lag

[87roach]

that's cause people who do the conversion use a factory fuel line instead of running their own one like this guy wants to. sorry i can't help

woops lag

Can't help you with the conversion. In my case I was able to use the factory line from an efi, all I had to do was drill a new hole in the firewall for it to go through(putting that line in was a bitch.. taking it out was too).

Good luck.

[Susanoo]

"this guy" wants to run his own line because i dont want to be like everyone else....many people i know have told me that im wasting my time doing all this but I wanna do it to be one of the few that have taken the time to do so. I mean when you get right down to it...the only semi challenging part is finding the right adapter. If it turns out that i cant find an adapter...i'll figure something else out, maybe even say fuck it and spend hours at pull a part, taking out the factory line...im sure you know...the damn thing is run in a way that its not easy to get out. I mean if you have objections to doing it this way...by all means. Obviously dont be a jerk about it but im open to suggestions and what not.

[ShyBoyCA6]

well factory is the way to go. its better if ya have a parts car so you wont rush into things and forget stuff.

[A18A]

are you gonna run the line under the car?

[Dr_Snooz]

Unless you have a lot of free time and money, it would be cheaper and much MUCH easier to buy an LX-i.

[cygnus x-1]

Ive got an 89 dx and I've been planning this project for a while. Recently I've been trying to get everything I need ordered and ready for the engine swap that'll be following the fuel system conversion. My current idea involves AN stainless steel line going from sending unit to the firewall, through a bulkhead connector, to an AN line fuel filter, finally to the fuel rail. I have the FI fuel pump that I pulled from a hatchback LXI. The only problem is how to connect the AN line to the stock sending unit and fuel rail. I was looking at using NPT to AN adapters, but I'll be honest, I don't know for sure what Honda uses. I think what they use is called a bonjo? And Jegs makes a banjo to AN adapter but it's apparently intended for use on the aftermarket carbs they sell. No idea if that will work for connecting to the sending unit. I know that two people on this board have done this conversion. One is named like carrotman or something and the other is like 87roach. Hopefully they jump into this and give their ideas.



Having done almost all of what you're planning, I can tell you some things.

If you intend to run the line inside the cabin I would strongly recommend using hard line, like steel. First reason is because it's cheaper. The second reason is because normal rubber fuel line (even the braided stuff rated for high pressure) allows some level of fuel to permeate through the wall. It's not much but it's enough to make the cabin smell like fuel if it's closed up for more than a few hours. If you must use flexible hose get the stuff that's Teflon lined. It costs a small fortune but should keep the permeation to a level that won't smell. If you don't believe me, google for "30r7 fuel permeation". I have the braided high pressure line in my 2g Prelude right now and I'll soon be replacing it with hard steel line. Granted it's harder to manage than flexible hose, but it's under the carpet so you'll never see it. And it won't smell.

For connection to the fuel rail, you need the AN to 12mm banjo adapter that Russel makes. It's towards the bottom of the page here:

http://www.russellperformance.com/mc/adapt_fit/fuel.shtml

The fuel rail you use may or may not have the pressure damper on it so you'll need to figure out which one you have. The pressure damper is a white sort of cap looking thing that screws onto the banjo bolt on the rail.


For the fuel pump, my Prelude has an external pump so I just used clamped rubber hose to go from the pickup tube to the pump inlet. With the factory in-tank pump you'll need a high pressure connection, preferably something with a mechanical fastener and not just clamps (although with the right hose and clamps you could still do this). What sort of fitting does the LX-i pump have? If it's a hard tube with something like a bubble flare you could always cut it off and put a regular single flare and use an inverted flare to AN adapter. Or if it's a push-on type or other threaded type there is probably an adapter to convert it to AN. There are adapters to AN from damn near anything if you look hard enough.


I'm also curious, are you doing a factory FI swap or something more exotic?


C|

[Susanoo]

Having done almost all of what you're planning, I can tell you some things.

If you intend to run the line inside the cabin I would strongly recommend using hard line, like steel. First reason is because it's cheaper. The second reason is because normal rubber fuel line (even the braided stuff rated for high pressure) allows some level of fuel to permeate through the wall. It's not much but it's enough to make the cabin smell like fuel if it's closed up for more than a few hours. If you must use flexible hose get the stuff that's Teflon lined. It costs a small fortune but should keep the permeation to a level that won't smell. If you don't believe me, google for "30r7 fuel permeation". I have the braided high pressure line in my 2g Prelude right now and I'll soon be replacing it with hard steel line. Granted it's harder to manage than flexible hose, but it's under the carpet so you'll never see it. And it won't smell.

For connection to the fuel rail, you need the AN to 12mm banjo adapter that Russel makes. It's towards the bottom of the page here:

http://www.russellperformance.com/mc/adapt_fit/fuel.shtml

The fuel rail you use may or may not have the pressure damper on it so you'll need to figure out which one you have. The pressure damper is a white sort of cap looking thing that screws onto the banjo bolt on the rail.


For the fuel pump, my Prelude has an external pump so I just used clamped rubber hose to go from the pickup tube to the pump inlet. With the factory in-tank pump you'll need a high pressure connection, preferably something with a mechanical fastener and not just clamps (although with the right hose and clamps you could still do this). What sort of fitting does the LX-i pump have? If it's a hard tube with something like a bubble flare you could always cut it off and put a regular single flare and use an inverted flare to AN adapter. Or if it's a push-on type or other threaded type there is probably an adapter to convert it to AN. There are adapters to AN from damn near anything if you look hard enough.


I'm also curious, are you doing a factory FI swap or something more exotic?


C|

I wish i had seen this sooner...i've already purchased a lot of fittings and 20 feet of stainless steel braided AN hose...

Had i seen this i would have gotten the fittings you suggested so i'll tell you what i got and we'll see if you think its ok. I went to my local aftermarket warehouse and got 2 x 12mm to -06AN adapter fittings for the rail and sending unit...I handed the guy the rail and sending unit and this is what he picked out...i had no idea russell made a 12mm banjo to -06AN...and it comes in black. So what i did was put the 12 mm adapter in there and attached a 90 degree male to female AN adapter...but im not even sure it'll clear the hoodline since my hood is off and i dont have any of the FI stuff on the car yet...IF it clears the hoodline, do think this will be ok? Is the pressure damper really needed?

I want to run it under the car actually...but where would you suggest i mount it? I dont want it to scrape when my car does :P I considered following the path of the exhaust between the wall and the heat shield but wont it raise the temp of the fuel and the hose?

EDIT

I found the fitting your talking about at my local store...http://www.tennesseespeedsport.com/Russell-640913-Specialty-Adapter-Fitting.html Thats the one without the pressure damper...the one with it is $19.99

[A18A]

a lot of cars i see with underbody fuel lines run them right beside a frame rail. minimal chance of the scraping there i suppose

[Susanoo]

Yea but my floor panels flush up just before the engine bay and just before the fuel tank in the rear.

Could you or someone else somehow show me the best way I could run this under the car. Like mspaint and some red lines would suffice.

[cygnus x-1]

Had i seen this i would have gotten the fittings you suggested so i'll tell you what i got and we'll see if you think its ok. I went to my local aftermarket warehouse and got 2 x 12mm to -06AN adapter fittings for the rail and sending unit...
Is the pressure damper really needed?


You could probably live without the damper. As for the rest of the plumbing, there aren't really any rules so... whatever works. I've been to plumbing adapter hell so I can sympathize. ;)




I want to run it under the car actually...but where would you suggest i mount it? I dont want it to scrape when my car does :P I considered following the path of the exhaust between the wall and the heat shield but wont it raise the temp of the fuel and the hose?


I think this is why the lines were run inside from the factory. I would try to keep it away from the exhaust as much as possible, but if you have to you could use some fiberglass insulating wrap or something around the line.

For routing, I don't have any suggestions other than just getting under there and figuring it out.


C|

[Susanoo]

What about down the rocker panel..? I could go up the fenders, behind the black plastic wheel well shield...

Here's some pictures that might help...

http://i54.tinypic.com/4rw7kh.jpg

http://i56.tinypic.com/16if41.jpg

http://i56.tinypic.com/2871zt0.jpg

http://i56.tinypic.com/10gjlz4.jpg

[Susanoo]

So...What exactly will i gain from running a new steel line versus using the factory hard line...

[cygnus x-1]

Either way you'll need another line since the carb cars don't return fuel back to the tank. The factory line is setup already for low pressure so it's easier to use it for the return and run a new high pressure line. But you could put flare fittings on the factory line to use it for high pressure and run a new return line.


C|

[A18A]

So...What exactly will i gain from running a new steel line versus using the factory hard line...

the only gain is not having to pull out all your interior to install the factory one

[Susanoo]

Either way you'll need another line since the carb cars don't return fuel back to the tank. The factory line is setup already for low pressure so it's easier to use it for the return and run a new high pressure line. But you could put flare fittings on the factory line to use it for high pressure and run a new return line.


C|

I know all this, the old feed line is used as the new return line. Usually a factory hardline is installed which does require a lot of interior to be removed. The drive seat has to be removed to change the ECU from the carb to PGM-FI. You can then pull the carpet to the side to reveal the current fuel lines. My backseats arent bolted down and the back part is out anyway for easy access to the fuel pump. The bottom part is super easy to remove so that reveals the grimmet where the high pressure line would normally come through. The dash has to be removed to change the harness since I would like the PGM-FI light...

So then with all that removed...wouldn't it be pretty easy to install the factory line?

If I ran a steel hard line, shoudnt I run it inside the car..requiring at least some interior removal anyway..?

[A18A]

So then with all that removed...wouldn't it be pretty easy to install the factory line?
yes.

[cygnus x-1]

... So then with all that removed...wouldn't it be pretty easy to install the factory line?

If I ran a steel hard line, shoudnt I run it inside the car..requiring at least some interior removal anyway..?


Oh, I misunderstood what you were asking. Yeah, you could just install a factory HP line since you'll have to take apart the interior anyway. The only advantage to running a new hard line is that you wouldn't have to spend the time pulling a factory one at the junkyard.


C|

[Susanoo]

Well my question now is if a 4 door LXi hard line will fit in my 2 door coupe...I'm unsure about having to rebend it...i've never run hard lines before.

Problem is that the 4 door LXi is the first in 3-4 months at my local pick and pull places...all of the 3g accords that came in were dx's

EDIT

Found out that the sedan is only .2 inches longer then the coupe....so i guess it shouldnt matter much...