1973 k10 fitech ultimate LS no fuel

[Mike_The_Grad]

Hey everyone. I swapped 5.3 lm7 with 4l60e into my buddies 73 k10. New everything. Fuel system, hydroboost, cooling system, the works. I also rewired the entire truck with american autowire classic update kit. Truck has power everywhere it needs it. Lights, gauges, fitech handheld works. Throttle position sensor responds in handheld, coolant temperature registers, fuel gauge works. When I crank the engine, fitech handheld shows no rpms. I did upload inital base tune from fitech menu. Hard set with key off. Fuel pump sounds like it's cycling. But there's no fuel pressure. I cracked fuel line at fuel rail nothing. Not even smell of gasoline. Tank is half full. I took return line off at corvette style regulator on frame. Nothing. Blew air back into tank and then rush of gasoline. So I connected it back to regulator. Cranked again. Nothing. No fuel at rail. Power to pump because gauge registers. I can hear the fuel pump cycle. But I don't feel the tank vibrate or anything. New walbro 255 lph in tank pump with spectra sending unit brand new in 1987 r10 fuel tank. Ptfe -6 lines all the way. Any help did i fry the fuel pump? How do I prime the pump even though I've cycled the key 25 times. After reconnecting the fuel return line to the regulator filter, I pulled the pressure line after the regulator filter and bone dry. Cycled key, check it again bone dry. What gives????

[Mike_The_Grad]

I also replaced the crank sensor and cam sensor this morning. Still no change in handheld rpms. Please help!!! Ha ha.

[LS short box]

Not trying to be clever here but do you have the FFR hooked up back wards? Also is it a GM or Wix FFR?
Maybe hot wire the pump and see if you are getting fuel to the FFR?
Is the 255 pump a "real" Walbro pump? Not an ebay special?
Out side guess is the 255 bottomed out in the tank blocking the sock on the bottom of the tank?

[Mike_The_Grad]

Ding ding ding, we gotta winner! Ha ha. Yes I had the fuel supply and return lines from the tank to the fprf swapped around. I was reading the website description where I got the fprf and it plainly says, the most common issue people have is mixing up the fuel supply and return lines. Supply being the outer port and the return being in the center. After a quick gasoline shower BAM fired right up. Got rpms, injector duty cycling, everything works at it should. Was able to get the transmission filled up. I have a leak at steering gearbox where I used a adapter fitting for the metric o ring pressure line to the original inverted flare gearbox. And a tiny drop coming from the plugged off temp sensor in the new radiator I didn't have to use because the fitech controls the electric fan trigger wires. Fired up the engine at least 6 or 7 times. Ran for few minutes each time. Hopefully get it to move under its own power tomorow. Thanks for the input. Happy to be a part of this site. Oh yeah, that sloppy mechanics stage 2 camshaft sounds awesome out of true dual 2-1/2" flowmaster exhaust with turn downstairs before the rear differential.

[jjzepplin]

Wow! That was fast! It appears that you are indeed CLEVER LS short box! Maybe a video of this running when you get a chance? I need to pick a cam out. Good job having only minimal issues on start up!

[Mike_The_Grad]

Here's a little video of me starting it up, revving it a little bit and hearing the exhaust. This is on a base tune included in the fitech handheld software. I'll be dialing in the settings and fine tuning in the next few days as I start buttoning up the truck. I'll take another video once some more fine tuning is done and compare the two videos to show the progress.

YouTube Link:
https://youtu.be/WhHTiMOXWDo?si=QFErdCOQr-bo6qox

[LS short box]

You know why I suggested the FFR might be hooked up backwards? Been there done that! LOL.
But you know there always is a but I would check the fuel pressure at the fuel rail. Hooking up the FFR backwards may have damaged the FFR and allow higher than 58 psi.

[Mike_The_Grad]

Thanks for the tip on checking fuel pressure. I will do that. I'm assuming you know from experience also on that point.

I fired it up again this morning to trouble shoot the leaking power steering gearbox pressure line connection. I found the brass inverted flare insert pressed into the gearbox had a visible ring/ridge around the inverted flare mating surface. I remember that being there before I threaded in the adapter fitting so I just spent the last couple hours extracting the brass insert. Ended up tapping the i.d. for 5/16-18 NC threads and using a piece of all thread rod along with my home made vice grip slide hammer to get it out of the gearbox. I planned on using my borgeson inverted flare brass insert adapters to replace the factory insert. But the stepped should o.d. of the two are different o.d. so now I'm scratching my head what to do.
1.lap in the factory brass insert back to sealing surface finish and press it back in.
2. Lap as above and lap the steel adapter fitting for inverted flare to metric o ring and give it a try.
3. Insert borgeson fitting and hope the adapter seals it up and no more leaking.
4. Combination of all of the above.
5. Replace steering gearbox. It looks to be original. And pretty well used. Any input??

[LS short box]

The Borg box comes stock with o-ring style pressure and return ports as I understand. You can get adapter fitting that screw in no brass inserts needed. I've used them a number times on later model steering boxes that used o-ring fittings.
But I'm using teflon lined -6 on the pressure side. Standard -6 on the return side.
Pic of my 68.