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Carb to efi fuel conversion help needed


toy-mota

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Hey 

im up to the stage of fitting the fuel system in my crown.now my ms65 had a carbie motor so no return line.

weres the best place to weld in a boss? I was thinking around the side/top (were the white lines are) .was going to tap into the filler pipe but shes a tight fit around the body .

what is the best fuel pump,fuel pressure reg and filter to use? I want something that is going to last but i am on a budget,also motor is staying N/A so wont be needing anything large.also thinking external fuel pump and mount inside the chassis rail .

 Cheers

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For a return line, I would suggest putting it into that access plate 100%. Fuel tanks suck to weld, and the danger of making it explode are super high. I welded my escort fuel tank and it was  a nightmare. Made it go boom after what we thought was thorough cleaning, although no damage to tank or people luckily. Also the material cracked around the welds, ended up sending it to a radiator repair shop and they spent hours soldering it up

 

I used a tomei fuel reg from aliexpress, it has been legit. My car currently also has an aliexpress bosch 090 fuel pump.

 

Can I also suggest that you do a good bunch of research before committing to some of the components, as the price of fittings/adapters can get a bit crazy

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I just put a T in the single original line on the Starlet, bigger fitting on the feed side and as big as I could fit on the tank source. It's not ideal but I've had no issues with it. Haven't yet had any issues with tank not being baffled either.

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Il look into an internal pump. Once the tank is bolted back up theres little room between the floor and tank 

ive washed the tank out and removed the sender and bung ,also put a flame to it and nothing happened,the tank has sat without gas in it for a few years now,but better to be safe.

china copies are fine? Id hate the thought of them leaking or crapping out on me 

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and fuel pressure reg has been fine, it has a gauge which has also been fine, have not adjusted it since installing

 

https://www.aliexpress.com/wholesale?catId=0&initiative_id=AS_20180112114510&SearchText=tomei+fuel+pressure+regulator

 

and the price is right. 

 

tbh I think china AN fittings arent too bad either these days

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When welding tanks,  run car exhaust through them for a while.  The carbon dioxide displaces oxygen. 

 

If it were me, I would go in tank. 

Nissans have a lush plastic surge tank that the pump sits in. Usually clip in at the bottom. 

And take a walbro pump. 

 

Hard part of intank is getting wires in there tho.

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8Hmmm. Would seem I got lucky and my tank had a return. 

 

However heres some pics. 

I ended up welding the pulsar flange into the top of the tank so I could fit the Nissan pump, and then made a plate for the top

I got @Steelies to make up some nylon bushes that go through a 3mm thick plate I welded into the side of the tank,  that with the combo of o rings allowed me to run power wires to the tank.

 

However on my crown sedan I bought a fuel proof wiring bulkhead boss thst seems to work ok.

 

Hope pictures make sense.

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On 1/16/2018 at 07:38, Carsnz123 said:

You need to buy that MS112 package with the manual sedan while you're at it. 

Haha i think one crown from there will be enough. Although that rusty coupe would make some nice garden art.

cheers for the help/pics seedy. Il look into this abit more

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  • 3 weeks later...

I was very close to running a returnless system as testament mentions, a few websites scared me off the idea but since I've been working on race cars for a few months, a lot of them run it and are running 600+ hp.  

I also dont recommend putting a t piece in the supply to the pump, you'll recycle the fuel heating it more and more each time until one day it'll vapor lock and be a cunt to figure out 

What I did end up doing was running my original supply line as the return, and drilling a hole and fitting a bulkhead an connector to an external pump and new supply line. 

Now I'm not saying this is the right way to do things either but it was very easy and seems to work alright. I didn't put a lot of effort in as I'm likely to fit an ally drop tank and surge tank setup at some point in the future 

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On 1/22/2018 at 13:01, Testament said:

a lot to be said for running the reg in the tank even and not needing a return line. works fine if you are going to be tuning the ecu anyway and are not looking at running lots of boost.

Yes but its a lot nicer to tune when your fuel pressure differential is stable (As in, your FPR is manifold pressure referenced) 

As it keeps your injector characterization more stable.

In which case you obviously need your regulator near your manifold.

Admittedly I'm fussy but I'd only run returnless if I had 3d deadtime data from the injector manufacturer. (And the ECU capability to use this)

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