What is the pros and cons of a tbi vs a vortec? What is easier to work on? What fails and what is the most reliable? Which gets better fuel mileage and what has more power?
The LT-1 derived SBC’s are superior to the TBI engines in just about every way. Also GM marketed their TBI-equipped 4.3L as a “Vortec” engine and then marketed the LT-1-based engines (multiport 4.3L/5.0L/5.7L) as “Vortec”, but wait, it get’s better, because their LS engines (4.8L, 5.3L, 6.2L) were also marketed as “Vortec” , so the term “Vortec” covers quite a bit of ground.
The LT-1-based engines have considerably more power, and get the same or slightly better fuel economy.
Note: by “LT-1 based” I’m referring to the multiport fuel injection V8’s that GM used in their trucks from around 1996 until the LS engines became the standard. I’m not talking about the current line of LT1 based V8’s that GM is using presently"
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TBI is a little simpler and probably more reliable. The vortec engines were prone to intake manifold gasket leaks where coolant could enter the engine oil. They were also known to have issues with the fuel injection unit under the intake that people refer to as the “spider assembly”. The vortec engines probably had more power. Possibly a little better mpg, but a negligible difference there. I assume you’re talking about the vortec 350, 305, and 4.3 liter V6 in the C/K trucks (1996-1999) Not the 4.8, 5.3, and 6.0 that came later in 1999.
One disclaimer, I’m not a pro mechanic.
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Yeah those are the engines I’m talking about. What would you choose?
What would you say makes them superior and what would you say about reliability? Major problems?
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Why are you asking ? I seriously doubt that there is a enough difference in every day driving to tell a difference. Repair costs depend on the problem more that anything else .
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If I was choosing between almost identical trucks, I’d prefer the TBI. I just really don’t know of any common issues with them. The Vortec, intake manifold gasket issues were pretty widespread. Not a huge deal if the coolant didn’t get into the oil or if you caught it very quickly. Chances are someone’s already replaced the gasket if it’s a high mileage truck. I wouldn’t really call either engine unreliable by any stretch, and I’d probably base my decision more on which truck was in overall better shape and appeared to be taken care of better.
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I have friends that drive tbi vehicles and dont like the vortec. They even wanted to convert one over to tbi after finding a good deal on a vehicle they wanted, the older s10 blazers with the v6. I just want to see what people are saying cause i really dont see the big deal. They say stuff about dealing with less computer crap in the tbi, but if you got a scanner whats the big deal
Both engines are computer controlled, so there shouldn’t be a ton of difference. The TBI engines were OBD1, and you could retrieve codes with a paperclip and counting the flashes of the check engine light. Vortec engines will be OBD2. You’ll need a scanner, and I suppose the engine control computer is a little more advanced and possibly a bit more complex. I think OBD2 is a little more sensitive to faults also.
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Why would you want an older Chevy truck with tbi . . . when you can get a newer Chevy truck with true efi with more power, better fuel economy, more reliable, and easier to diagnose
I know I would NOT choose tbi or any of the csfi variations
I would go for true EFI . . . and to be even more clear, I would choose a truck that had an electronic throttle body and a returnless fuel system. In other words, it would have to be model year 2004 or newer
And let’s be realistic here . . . any truck with tbi or csfi is pretty old by now, hence it’ll almost certainly need more work to keep it going
The older trucks are harder to diagnose and repair, in my opinion, even if you have a professional level scanner
So it’s not “computer crap”
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Just curious, why do you prefer an electronic throttle body? I have a 2005 Sierra that’s drive by wire, and a 2005 Lesabre that the throttle body is cable operated. I haven’t really had issues with either, but I prefer the throttle response on the Lesabre. I believe GM kind of desensitized the first little bit of throttle input. Probably to protect the drivetrain. I kind of prefer the cable.
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I’m not sure what i prefer, i like carbureted muscle cars lol. Im just trying to educate myself
Why? I am currently looking to replace one of my vehicles, due to needing repairs that I don’t have time to do, and am not willing to pay shop prices to have done. I am specifically looking for models that have a cable-operated throttle body and a radiator cap on the radiator itself, among other things. I also require the engine to be non-interference if it uses a rubber timing belt, and the water pump must be mounted externally, and driven by the timing belt, or accessory belt. I wouldn’t even consider any model which has an internal water pump driven by a timing chain.
Whenever I am considering purchasing a vehicle, I always look to see how difficult it is to do things such as replace the timing belt (if equipped), replace the accessory belt(s) and coolant hoses, drain and refill the coolant, change the transmission fluid and filter, replace the water pump, replace the radiator, change the spark plugs, etc. I would avoid buying any model which is unreasonably difficult to work on as a DIYer.
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Personal experience owning a 2002 truck with cable throttle and a 2004 truck with by wire throttle… The by wire gets better fuel economy and has no idle air control valve to clog up. I’d say I prefer the by wire throttle based on just those.
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No idle air control valve, but if drive by wire, it now has a pedal position sensor and an electric motor operating the throttle blades rather than the cable.
My fear is having to replace an entire throttle body assembly rather than just replacing a sensor on the drive by cable tb. Not sure how common that is, though.
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An IAC runs $30 to $60 depending on the model. The throttle body runs $110-$150 (for the Chevy). Both are easy to replace. One electrical connector and a few bolts for either one. Not a difficult service either way.
Looks like the drive motor itself is replaceable - called a TPS in the service listing - $65 but you need to drill out the rivets to replace it.
The pedal sensor is inside the car and not subject to nastiness. 137K on my drive-by-wire system with no issues.
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Yeah, I’ve got over 150k on my GM’s with no trouble with either TB (at least since I’ve owned them). One is cable, one drive by wire. The cable throttle just “feels” better to me, mainly. More responsive. I know they can make dbw systems as responsive (or more) than drive by cable. But GM seems to dumb down or numb the first little bit of throttle (tip in). My wife’s 2013 Toyota is very responsive though. May be a GM thing, or maybe they’ve improved since 2005. But they do still sell those “pedal commander” things to improve throttle response on dbw vehicles. So maybe I’m not the only one who thinks there’s some built in lag.
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Yes, but not for the reasons you might think. It improves fuel economy to “filter” the pump-pump-pump people do with the gas pedal. Drive on the highway with cruise control on in the middle of 3 lanes of traffic. Watch how many pass you, then fall back and pass you again. Many folks can not maintain a steady speed to save their life!
The mechanical systems are also designed to be non-linear. 10% throttle gives 25% at the TB. It make the car “feel” more powerful. That effect can be tuned with software on a drive-by-wire to identify a “take-off” from a stop and apply throttle more aggressively. Modify the response for throttle modulation (pedal pump-pump-pump) on the highway to smooth things out and provide better mpg’s.
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Interesting info. I do notice the folks on the highway who pass me and slow down. It drives me nuts! Use cruise control already, people!
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For the 350 the Vortec engine has about 45 more horsepower and more torque, it also doesn’t fall flat on it’s face above 3500 RPM. Fuel economy is rated as being slightly better per the EPA, but it’s not a huge difference. The Vortec engines have better heads, and multi-port fuel injection. As far as reliability, they should be comparable. On paper the TBI is simpler, but it’s not like multiport fuel injection is cutting edge stuff.
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