Carb vs tbi

[PlayingWithTBI]

All in - TBI

 

[Rick Reid]

keep the TBI ! I swapped over to carb and regret it in a daily driver

 

[Supercharged111]

Ya I meant tuning the computer, not tuning in a carb , thought that was obvious.

There was room for ambiguity with your statement and folks on here have done worse.

 

[Schurkey]

I’m in the process of completely restoring my dads 91 ext cab Silverado.

Words matter. There is a difference between "restoring" a car, and "fixing it up so it works, 'cause it's a neglected, high-mileage hoopty right now."

If you're RESTORING the car, you're keeping the TBI. And why not? They work seamlessly, get adequate fuel economy, get adequate power, get better-than-adequate emissions levels, and wonderful reliability.

Plenty of folks rip off a potentially fine-running TBI so they can slap on some Holley-and-open-element, and then figure out that they need to dick with fuel pressure, dick with ignition system, dick with the choke, rip off the catalytic converter 'cause otherwise it's gonna melt-down on too much fuel from the imprecise metering of the carb.

Yes, all that can be dealt with if you're careful and know what you're doing. Plenty of folks who rip off the TBI find out they're not that careful, and "oops!" DON'T know what they're doing. The end result is a vehicle that doesn't run right, stalls, hesitates, uses more fuel, can't pass an emissions test, stinks...but it's a hot-rod, and "They ALL Do That". If they're really lucky, they get a carb that has the correct linkage for the TV cable, Cruise control cable, AND the throttle cable, so at least they don't burn up the 4L60.

You've probably figured out by now that I think you'd be bat-**** crazy to carb-swap that truck.

FIX the TBI, make the fuel injection-computer control work like it's supposed to. OWN a scan tool so you have some idea how it's REALLY running. Leave all the fabrication and driveability headaches behind you.




PS. When you rebuild the engine, use pistons from an early-90s TBI Caprice or Roadmaster. They're flat-tops instead of dish, and very inexpensive. Gives you another quarter-point of compression. You'll also want to add a roller cam instead of the flat-tappet. Or--maybe--just find a "B" body (Caprice, Roadmaster) TBI short-block.

PPS: Before you play with the engine, verify all the "safety-critical items: Steering, Brakes, Suspension, Tires.

 

[alpinecrick]

Words matter. There is a difference between "restoring" a car, and "fixing it up so it works, 'cause it's a neglected, high-mileage hoopty right now."

If you're RESTORING the car, you're keeping the TBI. And why not? They work seamlessly, get adequate fuel economy, get adequate power, get better-than-adequate emissions levels, and wonderful reliability.

Plenty of folks rip off a potentially fine-running TBI so they can slap on some Holley-and-open-element, and then figure out that they need to dick with fuel pressure, dick with ignition system, dick with the choke, rip off the catalytic converter 'cause otherwise it's gonna melt-down on too much fuel from the imprecise metering of the carb.

Yes, all that can be dealt with if you're careful and know what you're doing. Plenty of folks who rip off the TBI find out they're not that careful, and "oops!" DON'T know what they're doing. The end result is a vehicle that doesn't run right, stalls, hesitates, uses more fuel, can't pass an emissions test, stinks...but it's a hot-rod, and "They ALL Do That". If they're really lucky, they get a carb that has the correct linkage for the TV cable, Cruise control cable, AND the throttle cable, so at least they don't burn up the 4L60.

You've probably figured out by now that I think you'd be bat-**** crazy to carb-swap that truck.

FIX the TBI, make the fuel injection-computer control work like it's supposed to. OWN a scan tool so you have some idea how it's REALLY running. Leave all the fabrication and driveability headaches behind you.




PS. When you rebuild the engine, use pistons from an early-90s TBI Caprice or Roadmaster. They're flat-tops instead of dish, and very inexpensive. Gives you another quarter-point of compression. You'll also want to add a roller cam instead of the flat-tappet. Or--maybe--just find a "B" body (Caprice, Roadmaster) TBI short-block.

PPS: Before you play with the engine, verify all the "safety-critical items: Steering, Brakes, Suspension, Tires.

All of this^^^............

 

[PlayingWithTBI]

AMEN!!!

 

[Pinger]

PS. When you rebuild the engine, use pistons from an early-90s TBI Caprice or Roadmaster. They're flat-tops instead of dish, and very inexpensive. Gives you another quarter-point of compression. .

Does that apply to Vortecs with SMPI also?

Out of interest, with the above engine, when modified and a 'tune' is added (eg, Blackbear), what's changed most - ignition timing or fuelling? Or both?

 

[Schurkey]

Does that apply to Vortecs with SMPI also?

I'd expect so. Vortecs have dished pistons. The Vortec and the TBI rings are different, make sure the rings match the piston.

Out of interest, with the above engine, when modified and a 'tune' is added (eg, Blackbear), what's changed most - ignition timing or fuelling? Or both?

I'd expect ignition timing AND fueling changes, plus other stuff like highway cruise, elimination of the speed limiter, etc. But I've never dicked with aftermarket "tunes", so what do I know?

 

[Brian sharp]

Yes, it will be a daily driver and yes it’s a frame off restoration the frame is getting painted next week and will start piecing it back together. My deal with the TBI (although I’ve never tried anything with them) is that I’ve read countless articles about how you can’t make power with them and that they have constant issues with them. And I’ve daily driven carbed trucks for year so I don’t see an issue with that.

 

[Brian sharp]

Yes, it will be a daily driver and yes it’s a frame off restoration the frame is getting painted next week and will start piecing it back together. My deal with the TBI (although I’ve never tried anything with them) is that I’ve read countless articles about how you can’t make power with them and that they have constant issues with them. And I’ve daily driven carbed trucks for year so I don’t see an issue with that.

Also I live in Oklahoma so cold weather isn’t really in my equation.