jaredi

So in the process of putting this IROC together I strung rubber fuel hose everywhere with the intention of replacing it with 3/8 aluminum hardline later.

Last night was the time and I ran aluminum fuel line from the stock TPI line on the drivers side down, across the K-Member then up and made a 270° turn into the mechanical fuel pump. I used standard Inverted Flare fittings and flares and I just plugged the line in the stock TPI line after the section of rubber high-pressure hose figuring that this would be a relatively easy spot to disconnect the fuel line if I ever decided to for some reason.

Heres the problem: When I went to start the car I expected fuel to eventually fill the little cheap plastic fuel filter I'm using, or at least get some in there. Well it didn't. It ran for some time and never got any fuel in the filter. Finally it ran out of fuel in the bowls and almost died.

I didn't understand what would cause this so I thought well I'll just crank it over with the starter with the fuel line unhooked from the carb (pointed in a gas can!) and see if it will get fuel that way. It would squirt fuel three or four times and then it would stop and the filter would empty out. So this morning I get the bright idea, hey why not pressurize the tank a little to help it out some. I stuck an air hose in the tank wrapped with a rage to help seal a little around the filler neck and proceeded to fill the tank with compressed air. Alot of it rushed straight back out the filler neck and vent tube but it built some pressure because it would still rush out for a few seconds after I let off the trigger. It still didn't fill the fuel filter but I thought hey maybe it got it to the pump. Coil wire was still unhooked so I cranked it over and the same happened but it looked like more fuel each squirt than last night so I stuck the line back on the carb, plugged the coil wire back in and fired it up. It sucked the filter dry in no time and there was no sign of any more coming into it.

The mechanical pump I'm running is a Holley 12-327-11 I put a 3/8" NPT to 3/8" IF fitting on the inlet of the pump and used IF fittings for the other two connections. The line is not kinked and the motor isn't hot enough for vapor lock especially sitting overnight.

Any ideas?

nelapse

iTrader: (17)

You did remove the intank pump right?

jaredi

Oh yeah almost forgot that part. Yes the in-tank fuel pump was removed and I grafted a sock onto the end of some 3/8 hard line and removed the TPI fuel filter. All was working well until I replaced that line.

nelapse

iTrader: (17)

I think you just have to get everything primed. Just shoot some starting fluid in the carb, or pour some gas in the carb and let it idle for a few. I have a feeling it will all work out. I know you sorta did already but try again.

Also, is the fuel filter in the right direction of flow?

They have an arrow that indicates which direction they should be in.

jaredi

Yeah filter is installed correctly, I'll try it again and report back...

jaredi

OK so I let it run for a while and sure enough fuel started coming into the filter but it never filled the filter like I could expect it to, there was just a very small amount just enough to reach the filter element. Is this normal operation? I have a friend and his filter is full, but his is an electric pump so...

Thanks,
Jared

nelapse

iTrader: (17)

Do not expect the entire thing to get all crazy. I mean does the car run fine?

You need to get a fuel pressure gauge, you can buy one with the hose barbs for like $5 at autozone or advance etc.

Apeiron

If you've got any leaks at all anywhere in the supply line from the tank to the pump, you'll be sucking air.

jaredi

The car runs as fine as I'd expect. It has no exhaust and hasn't been timed with a light and the carb hasn't been touched. Idles a bit high but runs good so all that can be fixed later.

I suppose I really should check the system for leaks as well. The only place I see where there may be leaks is the new line ends and where the fuel filter used to be.

Is there a way to purge the air up by the carb that I don't know about or is it just supposed to work itself out?

Apeiron

You don't need to purge the air up by the carb.

jaredi

Update. I found the (a) leak. It is at my connection between the factory line and the aluminum hardline I ran. I wrapped this with teflon tape the correct direction and torqued it down pretty hard.

The one thing that I question though, I've been doing single flares, should I have been doing doubles on everything?

Apeiron

Whichever your fittings require.

jaredi

It is just regular inverted flare stuff.

I'm new to plumbing...

Sonix

iTrader: (1)

Inverted flares don't care about teflon tape, that's only for pipe fittings. With inverted flare the seal is between the fitting and the flared pipe. If it leaks, tighten down on it harder, until it feels like something is going to break, then try again. I mean HARD.
Double flaring it works better, but i've single flared a lot of my inverted flare stuff and it's ok.

jaredi

I'll give it another go with the single flare tomorrow and if that doesn't work I'll cut the flare and double flare it and see how that does.