Why should I not go fully old-school carbed (OBS)?

[1995Tahoe]

Project & Daily: 1995 Tahoe LT

Question #1: Is it possible to go fully carbed and scrap a lot of the electronics associated with the TBI system? I would like to keep the A/C, radio, ABS, Alternator, etc, but I would be willing to sacrifice a lot in order to make the switch happen. Would I be able to keep the same engine? (I don't see why not)

Question #2: Is it going to be the way I'm picturing in my mind, like my '76 Chevy Monza used to be with it's carburetor and the way the engine worked? I'm looking for simplicity and tune-ability. Taking the intake manifold off of my Monz was like a 1hr job, but on this new TBI system with all the electronics, it's going to be more like an all day ordeal.

Question #3: Is it a financially practical route? Are there any potentially hidden costs and extras I might not be thinking about?

Thanks.

 

[AppocAlexx]

There is no reason you should remove your TBI system. Even if you could it would drastically reduce your MPG and HP. The computer is tuned with the TBI system as well as other components. There are tons of other things I am sure you can search and find how to get more power out of your stock set up. If you are actually going to do something this drastic then you would be better of building a new engine or buying crate engine, but then you will need a new trans or beef up yours. No point in adding more power if you trans cant handle it.

In all, don't remove your TBI system.

 

[drakon543]

It is very doable but you will infinitely have a check engine light on. Ditching the tbi will basically involve ditching all the other electronics. You will need a different distributor, carb style intake manifold, carb, probably an msd ignition setup, and modifications to atleast your fuel lines. Depending on where you live this modification could also greatly hinder getting your state inspection. Switching over to a carb removes the ecm equation as the carb and all its adjustments control the engine mechanically. Appoc is correct that you will probably lose mpg tho not drastic as suggested if you choose your carb correctly and are competent with the adjustments. As for hp also depends on your choices, if you cheap out and use on old stock style intake manifold and carb you will loose hp. If you purchase a basic edelbrock performance intake (or comparable brand) and a decent 4bbl with mechanical secondarys you will probably gain hp. If your looking for more technical diy tbi mods and parts for more hp feel free to continue your questions regarding that in this thread or p/m me directly.

 

[ccapehartusarmyINF.(ret)]

also dont forget fuel air mixture carbs have to be manually adjusted electronic fuel injection doesnt

 

[drakon543]

^ that will be another thing with the fuel system you will need to figure out. Your fuel pump is intended to work with a fuel injection setup. You should disconnect the factory fuel pump and remove it and use a regular pick up. You can put in an electric fuel pump but one intended for a carb.

 

[1995Tahoe]

There is no reason you should remove your TBI system. There are tons of other things I am sure you can search and find how to get more power out of your stock set up. If you are actually going to do something this drastic then you would be better of building a new engine or buying crate engine, No point in adding more power if you trans cant handle it.

It is very doable ... You will need a different distributor, carb style intake manifold, carb, probably an msd ignition setup, and modifications to atleast your fuel lines.

Sounds more expensive than I was originally thinking.

If your looking for more technical diy tbi mods and parts for more hp feel free to continue your questions regarding that in this thread or p/m me directly.

Thanks for the offer. Something crazy I just figured out today... After 179k, I'm pretty sure it still had the stock fuel filter on there!! this car was extremely neglected. Also, someone put a new water pump but put the old stat back in?! Who does that? As far as getting more power out of it, I know it has a lot of potential. I just need to keep addressing these maintenance issues as they come up until there are no more, then I would feel comfortable trying to make more power with it. It needs some A/C work, that's probably next.

I took the fuel filter off and installed a new one, and just out of curiosity I sprayed a bunch of carb cleaner into one end of the filter, it wasn't coming out the other side so I tipped it upside down and it was literally brown with black specs coming out. I did the same with the other side and very little fluid dripped out but when I turned it over same thing. Do you think I would need new fuel injectors after seeing how disgusting the fuel filter was? Thanks.

 

[drakon543]

With the engine at idle just check the spray pattern if you cant see a ring of fuel hitting the tb plate it might just need the secondary screens cleaned or replaced inside the tb. If you know your way around a carb you can probably take the tb apart with ease and clean it all up and using the rebuild kit it supplies everything you need to get it workong efficiently again. I did the tbi on my suburban in about an hr while being interrupted by some jehova witness people. Just take your time and get everything cleaned. While your in there tho there is also a spacer you can buy from various companies. It spaces the injectors up a bit more for better flow.

 

[1995Tahoe]

Changed the oil today. Bad sign #1: had to plow a screwdriver into the oil filter to get enough leverage to get it off. Bad sign #2: oil was not brown or dark brown, but pure black with smell of gas and complete with very small gray oil from the filter but not from the pan. Glad I changed it.

Regarding the TBI rebuild kit, I need a source for a good kit. Preferably one that includes those spacers like you said. Also planning to get throttle body spacer, don't need anything fancy. Do you think it's worth it to install fuel pressure gauge and regulator? Thanks.

 

[drakon543]

The injector spacer is a separate purchase i haven't found a kit that includes it.
Tbi intake manifols
http://www.summitracing.com/parts/edl-3704/overview/year/1995/make/chevrolet/model/tahoe
Tb spacer
http://www.summitracing.com/parts/trd-2534/overview/year/1995/make/chevrolet/model/tahoe
Tb rebuild kit
http://www.summitracing.com/parts/ado-219-607/overview/year/1995/make/chevrolet/model/tahoe
Tbi injector spacer
http://www.summitracing.com/parts/trd-2457
On the tb there is a bowl in thr back like a typical carb it has a diaphragm in thr back that acts as a fuel pressure regulator. Jet and a few others sells a retro fit kit to make it adjustable but unless your adding serious upgrades i dont thinks its needed. Next time you do an oil change use some lucas oil additive and continue to use lucas on every other oil change.

 

[drakon543]

As close as a tbi setup is to a carb i actually felt a noticeable difference when i installed a jet brand tb spacer. I dont like jet products generally but it was on sale and as far as the spacer goes its the same concept as any of the other brands. So thats why i linked you a transdapt brand its cheaper and does the same thing just doesnt look "pretty".