carburetor to tbi fuel injection

[Stoke]

What all is needed to change my carburetor to tbi fuel injection on my 1986 GMC Sierra? I have access to a 350 with tbi but don't have any idea how much work would be involved in such a swicth. Any help would be appreciated.

[Mr_Mac]

First off, welcome to the CTS forum!

As for a conversion, you may actually find it easier to just swap the engine out for one already set up with TBI. If not, then, at a minimum you'll need:

Intake manifold (and maybe the heads as well)
Crossover tube, MAF sensor and air box
O2 sensor
Fuel tank and pump
Wiring harness and EFI computer
EFI compatible distributor
EFI compatible coil/igniter
Knock sensor and relay

Plus you'll need to drill and tap holes for some of the sensors.

I'm sure I'm missing some parts here but maybe someone else can add/subtract from the list.

Mac

[Stoke]

Thanks for the welcome and the info. So if I can get an engine already set up for TBI it sounds a lot simpler. I guess then I would need the tank and fuel pump and the EFI computer and wiring harness if everything else is already on the engine?

[Mr_Mac]

You actually can retrofit your existing tank for use in an EFI system and the wiring can also be adapted. I had originally planned to get an older Chevy 350 and adapt it for EFI until I saw the costs involved and then opted for the complete engine/transmission from a late model Chevy C1500. As for wiring, I also have it easy there since I needed a new harness anyway, I got a harness (HAR-098) that allows for modern conveniences from American Classic Truck (http://www.americanclassic.com/asp/dyncatv2.asp?which=amclsall&p1=initial&p2=Wiring+Harnesses&iyear=1952&ytype=to&exyear=). Well worth the money!

Mac

[Stoke]

Thanks for the information. I think I have found a later model motor already set up for it and I think that is the way I will go if I do decide to do TBI. I am having the carb rebuilt on mine and if it doesnt work very well TBI will be my next project.

[Mr_Mac]

I don't think you'll be disappointed by changing over. The throttle response, better fuel mileage easier to maintain, etc all make it worth while!

[Steve]

I'm starting a simlar project for my 78, I'm installing a 93 caprice 305 TBI system. I have a running car for a parts doner. I'm going to use a 68 307 block rebuild the heads from the 305 and install a bigger cam, nothing wild just an RV cam. The only thing my tuner said I might need is a adjustable fuel regulator, so I can turn up the pressure to feed the new engine. I asked about installing a chip and he said that would be a waste of money.
Steve