Fuel injection or carb for LS engine

[Vombrown]

OK my good people. I'm upgrading my snow bear K-20 with a 5.3L I picked up pretty cheap locally with 20k on the clock. Now the issue is that it was a dealer take out so they removed all of the accessories, intake and exhaust manifolds. Not a big deal as parts for them are everywhere. When it comes to fuel injection, I confess that I am not all that savvy. I'm a diesel guy after all. Of course I've played with a few FI systems and stand alone systems but not on a scale of building one from scratch. The parts and updated computer/wiring harness/intake and throttle body are going to run 600 or so to replace. For almost that exact amount I can throw on a edelbrock LS carb intake and timing system. Minus the carb of course. So why not do that?

This is a project truck with a decent 350 in it and I'm not in a hurry to pull it until I get everything ready to install. Just seems a carb would be much easier for an old gear head like me to wrap my head around and tune. If after installing the full fuel injection system I have issues, I'm going to be lost in the sauce trouble shooting.

 

[dyeager535]

I don't recommend going carbed on anything anymore. Especially the LS', where the system is so good.

That said, piecing any injection system together is expensive. Another post I saw today indicated that person could remove a complete LS, trans, and wiring for $600 from their local 'yard. Hard to beat that.

Carbs aren't really any simpler than injection IMO, if people would take the time to tune them like they should, especially on a complex carb like the q-jet. It is a lot harder to dial in (really dial it in, not "jeez that truck in front of me is running rich" dialed in) a carb and vac advance distributor than it is to play around with timing and fueling on a laptop.

Remember...fuel injection does everything it can to keep the engine running, carbs do everything possible to try and stop it.

 

[blazinzuk]

Do injection.

Then do the harness yourself. Read. There is a ridiculous amount of info on LS swaps. Teach yourself the system. It's just sensors and a computer.

The injection will be better than a carb. For you specifically better at cold starts.

 

[Smokinthehippies]

Based on cold weather driving and elevation changes I don’t think carbs even stand a chance. Plus you can find a junked 5.3 and just take the computer and harness from that. As you have time you could go thru and weed out the wiring harness yourself then just have it tuned for what you want.

 

[Bent77]

Not that you need another vote.

Injection all day everyday and twice on Sunday. Best modification I’ve made to two squares now

 

[TreeFarm]

Run the stock ls. Like stated before a complete engine with harnees and computer is $600 at my yard. With that $600 they will let me pull anything else off the truck engine related for the swap too. I pulled a 2jz last summer and they were practically throwing parts in the back of my truck.

the LS engine is literally bolt in to our vehicles. all the stock accessories fit minus the factory AC compressor but that can be made to fit. Im running the stock donor battery cables and power steering hose on my swap. The only modification to the engine is to make the harness and ecm stand alone. you can send the harness off for a few hundred or just do it yourself and learn what you are working with. Send the ecm off to be unlocked and maybe a mild tune. LT1swap.com has all the instructions for the harness and will unlock your computer for a small fee. There are also youtube videos walking through it. Once the harness is stand alone, you only have 4 wires that connect to the truck, Constant 12v, ignition 12v, start 12v, and tach if you want that. Its almost too simple.

As for fuel system. I installed a walbro 255 #GCA758-2 in a stock EFI sending unit, adapted the metric O ring fittings and push lock fittings to AN. Used a corvette filter/reg combo and ran some hose up to the front of the truck. That part number walbro is a gm replacement and comes with the adapter wire harness and bushings to fit into a stock sending unit with no modifications. It couldn't be easier.

If it were me. I would pull a whole other LS at the junk yard to get a complete engine, then run the engine in stock form. obviously add a cam if you have the money. I can tell you that beating the piss out of my ~400hp 5.3 gets me 12 mpg. That is 12mpg doing 95 down the highway and shifting at 6500 rpm around town. If i drive nice im up in the 15+ mpg range. The truck also starts up when its cold as hell out no problem, doesn't care about elevation change, and will drive as long as I care to drive it with no issues. I have every part number I used for the swap in my build thread if you care.

 

[sweetk30]

ebay for good used or new take off parts like intake manifold .

 

[Vombrown]

I think I found a bad 5.3L with all the parts I need to do the swap. Pretty cheap and still in the truck so I can get all of it. I guess fuel injection is the way to go, I'm still hesitant honestly.

When did they start putting a serial port on computers to be tuned with a laptop? I thought the computer was ref lashed for the stand alone change. Didn't realize it was tunable after that. I know that the mega squirt and some of the others do but not the factory setup.

 

[tRustyK5]

https://www.hptuners.com/