TBI to Carb 1991 V2500

[big91burb]

Hey guys and girls just curious on how many people regret swapping out there factory TBI to Carb.

I have a 1991 V2500 Scottsdale 6+ inch lift on 37's that has been swapped from 4l80e to Th400 so take transmission out of the equation. The truck is extremely basic to begin with and with the 4l80e and what looked like rear ABS brakes taken out that leaves it even simpler.

I am considering changing out to Carb and HEI in the future just for ease of service\roadside repairs. Alot of my wiring has been butchered by a past owner, but the truck runs pretty good as of now. I have not had good luck with parts store parts (especially alternators) so the future of repairs to the TBI kinda worries me.

I appreciate all info and peoples experiences even might be open to aftermarket EFI

Thanks in advance
Jeff

 

[78C10BigTen]

I will be doing this in my 78 when my engine swap comes around. Im simply doing it because i bought a tbi engine at a good price and i dont want to swap my truck to a tbi setup. Much easier to remove and adapt in my case.

 

[big91burb]

Yes yours will be much easier wiring wise. Did you pull the mechanic fuel pump plate and see if it's drilled for the rod? Are you reusing your carb and distributor or getting all new? I wish I had found an older 3\4 ton suburban for this very reason but I couldn't pass the deal I got. If only a few years older with an SM465 and a 205 tcase body in the same shape would have been perfect! But we will get there. Truck has almost 3,500 dollars worth of wheels and tires on it now!

 

[78C10BigTen]

Yes yours will be much easier wiring wise. Did you pull the mechanic fuel pump plate and see if it's drilled for the rod? Are you reusing your carb and distributor or getting all new? I wish I had found an older 3\4 ton suburban for this very reason but I couldn't pass the deal I got. If only a few years older with an SM465 and a 205 tcase body in the same shape would have been perfect! But we will get there. Truck has almost 3,500 dollars worth of wheels and tires on it now!

I have checked the pump spot. Im gunna reuse my eddy carb, i bought a 4bbl eddy intake and brand new hei distrib. Plus brand new stainless headers for my install.

 

[big91burb]

Sounds awesome! So it was drilled for a mech pump?? I haven't checked mine yet but being a 91 (well probably a 91 I haven't checked the block numbers yet) I am guessing it isn't drilled.

 

[78C10BigTen]

Sounds awesome! So it was drilled for a mech pump?? I haven't checked mine yet but being a 91 (well probably a 91 I haven't checked the block numbers yet) I am guessing it isn't drilled.

I bought it from a trusted friend who pulled it from his lifted blazer, he confirmed to me that its drilled.

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[big91burb]

Looks alot like my motor! What year was the blazer?

 

[78C10BigTen]

Looks alot like my motor! What year was the blazer?

89-90. I dont remember 100%

 

[squaredeal91]

I converted from efi to carb lots of times and it's always been satisfying to me. Using a quaddrajet I've always gained power and mileage.

 

[gmbellew]

I'll be the dissenting voice and recommend sticking with the TBI. just get ALDLDroid and an OBD1 Bluetooth ALDL reader and download the GM manual for drivability and TBI is pretty simple to maintain.

 

[big91burb]

What info does the ALDL see? Can you see live info and make changes or just read codes. First I'm hearing about it. Kinda new to TBI, went from a 76 GMC to a 2002 2500hd which I had HPTuners and did all kinds of stupid stuff with. Now I'm going back......not a fan of new stuff. Way too much money for a quicker dying vehicle.

 

[RecklessWOT]

As far as fuel injection goes, the TBI setup on our trucks is as simple as it gets. I hate modern electronics myself, but these are not modern electronics. Unless you're building a race engine and have to have some massive carb on there to keep it happy, swapping away from TBI is a step backwards IMO. In stock (or mostly stock) form, the TBI gets better mileage and has a decent amount more power. There's a reason there was a 30 or so HP jump between '86 and '87, that was due to the introduction of TBI.

 

[gmbellew]

What info does the ALDL see? Can you see live info and make changes or just read codes. First I'm hearing about it. Kinda new to TBI, went from a 76 GMC to a 2002 2500hd which I had HPTuners and did all kinds of stupid stuff with. Now I'm going back......not a fan of new stuff. Way too much money for a quicker dying vehicle.

you see most key parameters the engine sees.

here is my main home screen in ALDLDroid

 

[big91burb]

Well damn! That looks like the torque app!

 

[gmbellew]

it also shows engine light codes, which you can get without an app, but is faster on the app. there's only a handful of things a scanner can do better - like command the computer to do a few functions.