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Old 06-03-2019, 12:25 AM   #1
chris989
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EFi or carb swap

Anyone switch their TBI to carb or aftermarket efi?
Did you use the OEM computer to control the timing?
What did you do for the check engine light when removing the TBI stuff?

chris
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Old 06-03-2019, 09:57 AM   #2
WyattTX
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Re: EFi or carb swap

You could probably get an entire Vortec engine out of a GMT400 with factory EFI for not much more than what the EFI conversion costs. It's probably easier finding parts for the Vortec engine than it is the the retro fitted sbc. If you went with a vortec swap, you could just use the ECM that came with it. If not, just pull the bulb out of the check engine light socket.
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Old 06-03-2019, 10:05 AM   #3
SCOTI
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Re: EFi or carb swap

Quote:
Originally Posted by chris989 View Post
Anyone switch their TBI to carb or aftermarket efi?
Did you use the OEM computer to control the timing?
What did you do for the check engine light when removing the TBI stuff?

chris
What does your drivetrain consist of?
What kind of mileage?

I ask only to better understand the intent behind your question.
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Building a small, high rpm engine
with the perfect bore, stroke and rod ratio is very impressive...
like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.

Cubic inches is like Indiana Jones with a cheap pistol....
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Old 06-03-2019, 10:07 AM   #4
Ziegelsteinfaust
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Re: EFi or carb swap

Like he said, and even a 5.3 complete is quite cheap these days.

It all depends on a budget, and what you have wrong.


Is there something wrong with the TBI?
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Old 06-03-2019, 10:58 AM   #5
kipps
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Re: EFi or carb swap

Check out your engine core very well before paying a bunch for a new fuel system. A lot gets blamed on the TBI with its associated wiring issues. That's the reason my TBI engine got pulled. I suspect now, that a lot of the problems with run-ability and power were because of wiped cam lobes. I'm told it's a common problem with those flat-tappet engines.

Check compression, do a leak-down test, pull the valve covers and confirm that the valves are all opening adequately. If all that checks out, then consider spending money on the fuel system.

Keep in mind that any system you go with; carb, TBI, aftermarket injection, or LS swap, you'll need to learn it thoroughly and plan on doing all repairs yourself. No mechanics remember how to diagnose and fix the old TBI stuff, based on my experience. Likewise, you can't assume they will be willing to work on anything aftermarket. If you're going to the bother of learning a system, it might as well be a LS.
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Old 06-03-2019, 01:07 PM   #6
chris989
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Re: EFi or carb swap

Quote:
Originally Posted by SCOTI View Post
What does your drivetrain consist of?
What kind of mileage?

I ask only to better understand the intent behind your question.
It is a gm crate tbi with a small lunati cam. the motor is out and at the machine shop because it ate the thrust bearing at 20,000 miles.

It ran fine before but i was thinking while it is out and tore down i might put a roller cam in it and possibly upgrade the heads. the motor lives under 4,000 rpm. mostly under 3000.

it is a 89 v2500 burb, 5.7, 4l80, 456 gears, 34 tires. mostly for towing, camping, running around town.

Chris
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Old 06-03-2019, 01:53 PM   #7
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Re: EFi or carb swap

Quote:
Originally Posted by chris989 View Post
It is a gm crate tbi with a small lunati cam. the motor is out and at the machine shop because it ate the thrust bearing at 20,000 miles.

It ran fine before but i was thinking while it is out and tore down i might put a roller cam in it and possibly upgrade the heads. the motor lives under 4,000 rpm. mostly under 3000.

it is a 89 v2500 burb, 5.7, 4l80, 456 gears, 34 tires. mostly for towing, camping, running around town.

Chris
A crate TBI replacement motor (for an 89 TBI set-up) should already have a hyd roller cam.
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Building a small, high rpm engine
with the perfect bore, stroke and rod ratio is very impressive...
like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.

Cubic inches is like Indiana Jones with a cheap pistol....
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Old 06-03-2019, 02:13 PM   #8
chris989
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Re: EFi or carb swap

Quote:
Originally Posted by SCOTI View Post
A crate TBI replacement motor (for an 89 TBI set-up) should already have a hyd roller cam.
it cam flat tap. has the provision for a roller.
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Old 06-03-2019, 06:57 PM   #9
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Re: EFi or carb swap

Quote:
Originally Posted by chris989 View Post
It is a gm crate tbi with a small lunati cam. the motor is out and at the machine shop because it ate the thrust bearing at 20,000 miles.

It ran fine before but i was thinking while it is out and tore down i might put a roller cam in it and possibly upgrade the heads. the motor lives under 4,000 rpm. mostly under 3000.

it is a 89 v2500 burb, 5.7, 4l80, 456 gears, 34 tires. mostly for towing, camping, running around town.

Chris
IDK..... Vortec heads are top choice for a torque motor which is what you need. If anything, the Hyd roller option w/some better numbers vs. OE would only help. The current standard of people saying "Swap an LS into it" makes sense when starting w/NO or a broken drivetrain & only if/when you have extra time + money (especially when it's not a project). If everything else is relatively fresh there's nothing wrong w/making what you currently have work. With only 12K miles & you're already tweaking on it for an issue, I'd say fix what was broke & go from there.

As for the original question of aftermarket EFI/TBI, the more affordable TBI based units are easier to adapt to existing OE set-ups & offer easier tuning vs. OE TBI but I just wouldn't trust an ECM that's sitting on top of a hot intake to live a long life & integrating to the OE stuff (or eliminating what isn't needed) is going to require tedious work in your electronics heavy burb. I know guys that run the Fi-Tech TBI w/o issue (one on a older C10 w/a sbc/383/roller-cammed weekend warrior; the other on a TT'd SBF 32 weekend warrior). *The Holly Sniper is a similar set-up*

A separate ECM mounted on a fender-well or in the PASS compartment would be my choice which means going up the price scale for a set-up (still TBI but w/a remote ECM). Those would possibly be easier to integrate w/your Burbs existing electronics (speedo, gauges, etc).
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89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides

Building a small, high rpm engine
with the perfect bore, stroke and rod ratio is very impressive...
like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.

Cubic inches is like Indiana Jones with a cheap pistol....
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Old 06-06-2019, 08:23 PM   #10
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Re: EFi or carb swap

I went from a 350 tbi to a crate Vortec 350 and a quadrajet carb. It was pretty simply and has been running great for 5 years now.
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Old 06-06-2019, 11:55 PM   #11
SunSoaked
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Re: EFi or carb swap

All you need to know on this gynormous piece of junk.
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Old 06-07-2019, 09:18 AM   #12
chris989
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Re: EFi or carb swap

Quote:
Originally Posted by csdineley View Post
I went from a 350 tbi to a crate Vortec 350 and a quadrajet carb. It was pretty simply and has been running great for 5 years now.
How bad did your gas mileage drop with the carb?
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Old 06-07-2019, 10:17 AM   #13
JHILDE
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Re: EFi or carb swap

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Originally Posted by SunSoaked View Post
All you need to know on this gynormous piece of junk.
Elaborate.
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Old 06-07-2019, 11:33 AM   #14
WyattTX
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Re: EFi or carb swap

Honestly, if you put effort into keeping them up, the Q jet on top of an old sbc works well. Fuel economy will take some tuning, but there is plenty of q jet literature out there. Maybe you could adapt your truck for cruise control while your at it.
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Old 06-07-2019, 03:28 PM   #15
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Re: EFi or carb swap

It went from 12 mpg to 14 mpg avg. 16 mpg is the best I've ever got.
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Old 06-07-2019, 08:28 PM   #16
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Re: EFi or carb swap

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Elaborate.
Search Sweetk30's posts on his trials with his Holley Sniper and you might be tempted not to buy it.
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Old 06-07-2019, 11:47 PM   #17
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Re: EFi or carb swap

Or my posts. Better yet read the Sniper forum "Sniper" on the Holley Website.
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