Carb LS with factory ECU

[Jrgunn5150]

I typically keep my Youtube and forum persona's separate, but it seems not a lot of people know this is a thing.

100% stock PCM, VATs in tact, cheap Amazon harness, carb intake, carb, runs...

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[Rustisbest]

Congratulations. Why not a $50 marketplace Edelbrock to match?

 

[Jrgunn5150]

Congratulations. Why not a $50 marketplace Edelbrock to match?

Can use any carb you like.

no matter what brand you choose someone will be along to tell you it's the wrong brand regardless.

Point is to demonstrate no aftermarket boxes, harnesses, MSD, Dakota are needed to make the switch to a carb.

 

[Ricko1966]

I thought everyone already knew that. But you lose the big thing everyone attributes to the LS swap,drivabilty and fuel economy. The big reason for the better mpg and drivabilty is the fuel management. If I was going to stay carbed,I'd save the 1000.00 showed in your video and the other 1000.00 I was going to spend on,mounts exhaust,other knick knacks to make the swap and spend it towards a fresh rebuild and have a new engine that bolted right in and was going to be trouble free for 100k miles.

 

[Vbb199]

Pretty cool you can make it all work with the factory pcm. No reason you cant i guess.

Good info to know , I had a buddy that had the audacity to 5.3 swap his 85 c10 but it had a carb and msd box, with the factory coils.
What size carb did you run? 800? 850?

I must know myself, why run without the plenum and injectors? Like what does it gain? 2/3 of the pcm for your Gen 3 is dedicated to fueling and airflow management practically. Theres variables in those two critical components of combustion that are also responsible for adding and removing timing control dependent on barometric pressure, manifold pressure, and airmass

So what did you do? Put the pcm in speed density and ses disable 300 codes?
How do you handle power enrichment mode?
So many questions

 

[Jrgunn5150]

The whole point is you don't have to do a single thing to the PCM.

Add carb, crank, it will run exactly the way it is without a single piece of software.

 

[Vbb199]

How is vats in tact too?

What did you do for the map sensor?

The spark table advances spark based on airmass from the maf. Without the maf, it uses the map. So surely it has a map connected

 

[Jrgunn5150]

How is vats in tact too?

What does Vats do in an LS PCM?

 

[Ricko1966]

How is vats in tact too?

What did you do for the map sensor?

The spark table advances spark based on airmass from the maf. Without the maf, it uses the map. So surely it has a map connected

I'm guessing it's running on a factory default tune for limp mode. Vats shuts off injectors but not ignition.

 

[Jrgunn5150]

I'm guessing it's running on a factory default tune for limp mode. Vats shuts off injectors but not ignition.

Indeed.

Vats, when a signal is not received by the BCM, cuts the injector ground. Coils fire based on cam and crank sensor position. As long as they keep getting signals, they'll keep firing. Could be spinning with a squirrel in a cage on the crank pulley for all they care.

 

[Vbb199]

so i still havent gotten an answer on manifold pressure detection and whether it exists or not. Its cool you got it running and all

 

[CountKrunk]

So it runs but in limp mode so it's not a setup you would actually run in the truck right?

 

[Jrgunn5150]

so i still havent gotten an answer on manifold pressure detection and whether it exists or not. Its cool you got it running and all

You're acting like this is an interrogation, or as if I'm selling you something lol.

Do it, don't do it, I'd lay money on you won't anyway, but either way it's not like I owe twenty answers here.

 

[Jrgunn5150]

So it runs but in limp mode so it's not a setup you would actually run in the truck right?

What limp mode?

It will run exactly like this in the truck.

Let it flash all the codes it wants to the nonexistent MIL.

 

[CountKrunk]

What limp mode?

It will run exactly like this in the truck.

Let it flash all the codes it wants to the nonexistent MIL.

I was referencing @Ricko1966 's post RE limp mode.

So it just runs normal? Have you dyno'd such a setup? Just to see if its the same/similar considering it's a carb setup.