K10 Project

[JoeliusZ28]

So, I'm trying to get this truck running by Sunday of this weekend so I can take it on a road trip next Thursday. I just found out that the Fitech fuel command center designed changed... or rather the function of it changed, I knew it was a revised unit. It now requires a return line to the fuel tank which is a bit of an issue on a K10 that never had a return with dual tanks. Their original fuel command center didn't require this. I need to figure out what I can use instead and get it ordered it quick. If anyone happens to know of something here I'm open to suggestions!

[MP81]

That's weird they changed the design that drastically...did they say why??

[JoeliusZ28]

Its to circulate fuel to prevent pump overheat and vaporlock. Which is great except for the fact I can't use it.

[JoeliusZ28]

Edelbrock makes a similar unit that has floats to regulate the fuel flow, but they also "require" you to vent to the fuel tank and one of the reviewers posted that venting to open air didnt work as it dripped continuously.

I think i can still get the original fitech fuel center from a different source, but it wont arrive in time and this all has me questioning how robust of a setup it would be even if i did do that. Blah.

[MP81]

Well if the original doesn't have the return line, then would it be prone to vapor lock and/or frying the pump?

[JoeliusZ28]

Pretty much.

Coworker may have come up with a simple enough solution to use what i have, I'll have to look at things tonight when i get home.

[JoeliusZ28]

Well it took a few hours of research and brainstorming with a friend and coworker but I've devised a plan to make this work. Probably costing me about $250 in fittings and lines, but it is what it is. Anyway, both fuel tanks have a filler neck vent that is about 1" hose on each tank. I am going to run the return back between the tanks, tee it off between the two, and then tee into the filler vents on each tank. The vents are big enough that there cant possibly be enough fuel coming back to block/pressurize so that won't be a problem. It'll return fuel to both tanks equally and if one tank happens to fill up the pressure in the vent will dictate that all fuel has to go to the non-full tank. It seems simple enough in theory, and hopefully it works. The only issue I can see with it is that fuel consumption from a given tank is never going to be accurate as far as an mpg reading. If it proves to be a problem I can look into a way to make the return move with the tank, but almost all of the lines/connections would be the same with the addition of a control valve.

[MP81]

I think it sounds legit. Regarding MPG - how do the dual tanks work? Is it automatic - as in, will it always pull from the front tank first, or is there a switch?

Have you consulted Fitech? I'm curious if they've ever dealt with a dual tank situation before.

[JoeliusZ28]

There?s a switch on the dash to change tanks.

And im sure they have, dual tank trucks are probably the headache they didnt plan for when creating these products haha.

Long term what i will probably do is put a second diverter valve in for the return and either tap the wiring into the existing switch or install a second switch for the return. For now i just want to get it running.

[JoeliusZ28]

Other than Friday night I worked the entire weekend on this project. Had help from my dad and a couple friends too. The entire thing with the exception of the distributor and valve covers is installed. Air conditioning will come later too. I got gunshy on starting the engine last night because I used the oil pump drill primer for a minute or two and wasn't seeing any oil through the pushrods. But I might need to give it more time with the drill and turn the crank slowly to make that happen. Hoping to start it tonight. Couple more pictures of the completed-ish install. My road trip to St Ignace is Thursday so im crossing my fingers for a successful break in and a couple hundred drama free miles prior to then.

project3.jpgproject2.jpgFitech1.jpgFitech2.jpg

[MP81]

That Fuel Command Center looks really clean - as does the Fitech unit itself.

Out of curiosity, I sent Dakota Digital an email about Fitech integration with the HDX cluster I have, as they have available with Fast XFI, MSD Atomic, MegaSquirt, Holley Sniper, etc, but they said those are all CANBus systems, and the Fitech isn't. Might actually be easier, since all I'm needing to see is a tach feed, which comes out of the distributor...where my feed is already tapped into.

[JoeliusZ28]

Yeah doesn't seem like CAN integration between those two would be necessary for a system that is retrofitted on an originally analog vehicle.

[MP81]

Yeah - nothing extra that I'd need to see anyway. Plus, I'm already getting readings from extra coolant temp and oil pressure sensors, so there's nothing else the EFI system would need to tell me.

[JoeliusZ28]

A friend came over and helped me button it up tonight. We got all the lifters to prime in about 3 minutes with me running the drill and him turning the crank over.

After that we started it. Unfortunately it was not drama free but i dont think it was doom and gloom either. Cam seemed nice and quiet and even though something is WAY off with the tune i can tell it has the potential to run way better than it ever did before. Had some surprising throttle response. I need to figure whats wrong with the tune next. It takes lots of throttle to get it to start and once it does it struggles to get the rpms up. Once its above 2k it runs fairly well but then there is so much vacuum it practically locks the throttle blades in place and i was having a hard time gently throttling it without it suddenly snapping WOT and shooting fireballs. I think the base tune is pig rich.

https://youtu.be/_CwlF2tSNu8

[MP81]

Isn't it supposed to tune itself? Can you tweak it manually?