84 C3500_Converting from Carb to TBI-Updated

[GalDemSuga]

Guys

It has been awhile since I have been on the Forum. I made a new friend and she has a 1984 C3500 Crew Cab Dually that runs like crap. She has put a lot of money into the truck and loves it. I suggested that maybe we can swap from Carb to TBI. The truck has a 454 in it. I will post pics later today when I get home. I gave her a 1227747 computer that I kept from my last TBI K5.

I would appreciate any suggestions from the forum members.

 

[sweetk30]

more info on bad running ?

I scored a bbc 454 in a burban 1 time for bad running and just needed a cam . 4-5 lobes were about flat .

 

[GalDemSuga]

more info on bad running ?

I scored a bbc 454 in a burban 1 time for bad running and just needed a cam . 4-5 lobes were about flat .

First issue was the dist module which she solved by replacing it. Next issue is that something is killing the battery.

The truck was originally a diesel which she swapped for a 454. I am not sure who did the work for her but it hasn't been right ever since the swap. The carb is not efficient so I suggested she go to a TBI setup and prosper. The engine bay is a mess of wires and hacked up AC etc. She wants it all back and complete.

I will help her get it done but I need guidence.

 

[dyeager535]

That is still the "early" fuse panel (blade fuses, but accessory terminals scattered around) right? It's a lot of work, but if the interior wiring is just as questionable, finding an '87-91 truck and just taking the entire harness (interior and engine bay) would be my choice.

I converted mine over to EFI (wiring same as TBI essentially with just a few more wires) and used the original 80's fuse panel, but you add a fair number of wires, have to figure out how to fuse the leads properly, etc. If I was planning to go to TBI, swapping to a stock TBI harness would have been the no-brainer solution.

 

[GalDemSuga]

I wonder if a 350 TBI intake would work for this swap?

 

[Zeus33rd]

I think running it on propane would be simpler by a mile and drive-ability will be very very close to a TBI motor. Carbs can piss off.

http://www.gotpropane.com/

 

[dyeager535]

Not on a 454. Bunch of options here. There were 454 TBI intakes. Early on GM used the q-jet intake with a heated adapter for TBI on it. There are also aftermarket carb to TBI adapters.

 

[Zeus33rd]

'92 TBI 454 intake-

 

[Blue85]

There were 454 TBI trucks. You'll want that intake, throttle body and injectors. Don't try to use SBC stuff. If you can't find factory BBC stuff, look at aftermarket.

 

[dremu]

A bit spendier than junkyard, but you could do a brand new wiring harness to do the conversion. Most of them (Howell, for instance) builds them to your spec, i.e. with/out EGR or whatever other options. Then you get a new intake (or adapter for your existing one) and collect the various parts new or used as desired.

They also sell complete kits (even spendier) but with all new GM parts, the intake adapter, etc.

-- A