Injector hose inner diameter

[robftw]

I'm too afraid to take my injectors off the car for fear of cracking the rubber, and i don't have my new set yet.

I will be going to home depot in about an hour to get supplies to build my own fuel rail. If anyone happens to know this off hand it would be greatly appreciated.

Or alternatively, if anyone knows the correct barb size i should buy that would work too.

[Zed Head]

Pretty sure it's 8 mm metric, but 5/16" works fine. 5"16" EFI hose, 5/16" barbs.

[robftw]

Pretty sure it's 8 mm metric, but 5/16" works fine. 5"16" EFI hose, 5/16" barbs.

Thank you!

Hopefully they have it in 5/16, its an odd barb size.

Worse case scenario i have to get 1/4 But i think i can make those work with good non-gear clamps

[FastWoman]

Yeah, I used 5/16" throughout when I did mine. Don't get 1/4" hoses, because they will eventually split on you.

[robftw]

Okay i just got the stuff i needed, they didnt have 5/16 so i got some 1/4 inch instead.

i plan to use the original hoses, but things will be relocated a bit. everything in this image is in the correct order right? or am i missing something..

Cold start will be deleted, charcoal can is deleted.

Brake booster is still there, but its not drawn.

[bluezcrazy]

Not saying you are an idiot, but be sure to buy Fuel Injection Fuel Hose, or High Pressure Fuel Hose. If you do end up replacing any of the injector hoses. Took me many times to figure out why I had to replace them so much on my 78 I used to have. Was buying the wrong hose.

Bryce

[Zed Head]

You don't need the T before the fuel rail. If you're using the stock regulator, you could T after the rail, or block one port. If you T before the rail, you could get a pressure imbalance between the two lines. And fuel could sit in the rail, heating up, while the main flow went through the other side of the T. It might not be a huge deal but if you T after the rail you'll ensure that all fuel passes through the rail on it's way around and back to the gas tank.

Doesn't the 78 FPR have just one inlet line anyway. Maybe you're using an aftermarket FPR?

[robftw]

You don't need the T before the fuell could sit in the rail, heating up, while the main flow went through the other side of the T. rail. If you're using the stock regulator, you could T after the rail, or block one port. If you T before the rail, you could get a pressure imbalance between the two lines. And fue It might not be a huge deal but if you T after the rail you'll ensure that all fuel passes through the rail on it's way around and back to the gas tank.

Doesn't the 78 FPR have just one inlet line anyway. Maybe you're using an aftermarket FPR?

I was actually considering capping one end of the FPR, and running one line instead of a T fitting. Has anyone done this? and are there any negative effects?

And i never thought about a pressure imbalance, and i have a 77 engine but the FPR is a 4 port unit (including vac)

[Zed Head]

It should be okay. Datsun went to one inlet to the FPR in 1978, and modified the fuel rail to fit. The fuel will flow through your rail, hit the FPR and flow through the FPR when the pressure builds up high enough to push the valve off of its seat.

It would more likely be a flow imbalance. The FPR valve doesn't care where the flow comes from it just opens at a certain pressure.

If you wanted one less fitting, you could get a 1978 FPR. It will bolt up in the same spot but only has two ports, instead of three.

[robftw]

Well i got everything back together and buttoned up, did a wire tuck too and cleaned up the engine bay. (minus the shaved intake manifold thats what my spare one is for)

I took the advice in this thread and capped off one end of my FPR and re-routed the fuel lines so everything is nice and cleaned up, the FPR sits on the firewall now

One problem though.. it appears one of my injectors was replaced at some point and the rubber hose coming out of it is 1.5'' to short, if anyone has a single injector they are willing to part with please let me know.. they are 62$ each new

I'm not installing my new ones yet because i don't have the ECU to go with them.. damn boat mail sucks!

[FastWoman]

Rob, I've got an extra injector I could part with. However, you can replace that too-short hose easily enough. It would be better to use the injector you have (matched to the others?) if it works. Just get a razor knife, and carefully slice through the rubber around the injector's barb, so as not to nick the barb itself. Cut at a shallow angle, just deep enough to slit through the reinforcing layer. Then work the hose out of the end cup thingie, and pull it off at an angle. Remove the cup, and attach a new hose with a regular clamp.

But if you're not able to do this, let me know, and I'll send you an injector.

[robftw]

Sent you a PM

Edit,

if anyone needs anything off of my N47 intake manifold let me know, i have the cold start, air valve, all the emissions crap and charcoal canister.. just pay for shipping and its yours.

I also have the L shaped metal hose adapter that goes to the TB

Edited July 30, 2011 by robftw