tbi fuel injection

[54 jimmy]

i'm thinking of putting a 88 tbi motor in my 54 gmc but want to know how hard it is to re-use the factory wiring. any thought on this would be great. i have the motor,computer,and wiring harness. wiring diagrams or any help.

[dewey777]

I am installing TBI as well. I have heard that the 90 suburban is the best to use as the computer is pretty well stand alone. There are a few wires that can be removed from the harness. I bought a complete TBI from another member on this forum and he removed the non required wires from the harness while still in the vehicle. He could then continually test run the engine while he removed wires - SMART!


Or you can ditch the factory wiring harness and buy a painless.....

[smittster]

I used the engine from an 85 corvette and used a wiring harness from TheDetailZone.com
and it is working fine.

[54 jimmy]

i don't want to buy a harness as i have this complete setup and would like to make the factory harness work. if i can't use the factory harness then i will stay with my current motor. i have no funds for buying a harness and the wife says i can't buy one so that is it in a nut shell.

[chev3600]

As long as you have the harness with the firewall passthrough and everything, hooking it up is really easy. Running the gm column makes it even easier because you have the key cylinder. I'm using a stock gm headlight switch even. Little to no mods. The computer only needs a power and ground at that point.
Thinning the wiring harness is much less fun, and not completely necessary. The ECM will need to be tuned to eliminate the emissions stuff, then.
Also consider how or what gauges you want to run. And the lockup for the torque converter.
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[54 jimmy]

i would like to make the harness a stand alone. so yes i want to thin the wires. i bought a ez wiring harness to run my carb motor and would like to use this harness with the factory tbi but stand alone. the 88 doesn't have a lock up converter. so i don't have to worry about that. as far a gauges i am running sunpro mechanical ones. my motor doesn't have a polution pump or that odd junk. i don't care if i have to leave the charcole canester or the egr that doesn't bother me. i want to do a easy simple cheap tbi swap.

[Thadious]

I started with a 91 S10 harness and thought the same thing... then opted for a used Painless a guy here was selling. If I knew you were looking, I could have made a diagram of the colors you need to run it and you could have thinned it. I have two harnesses now... one for engine controls, one for chassis... and it makes things alot easier to troubleshoot.

I understand your point though and a drawing of a properly chopped harness would be invaluable to the boards.... something I'll look at when I pull mine apart for paint!

Making a stand alone engine harness from a regular TBI harness would be easy if you knew which wires needed to stay! There's only a couple of fuses in the painless one and a couple of relays... it's not really that hard.

I'm running an 88 350 TBI in mine as well...

Cheers,
Ted.

[RootBeer 6117]

54
At school we have a 95 350 TBI setting on an engine stand, the students wired it up and we run it,some times I bug it and they have to find the problem.I used the wiring harness from a 94 chevy truck I had all the harness dash column etc. I think it it is easy to do but I did a 87 tbi in an 81 Chevy 10 yrs ago . If you need help with wiring diagrams or questions I'll be gald to help.
Joe

[54 jimmy]

thanks Thadious and RootBeer 6117. i could use a diagram that tells me what wires do what so i cam make that determination when the time comes to start this. the motor,wiring,and computer are still in the truck that i am going to get them out of. that won't happen till it gets warmer but it is good to know that i can make the motor stand alone from the rest of the truck.

[BlueJeep]

It's really pretty easy. There is a large bundle of wires that goes off to the passenger side, these mainly go to the ECM. The other plug near the ECM (and white DRAC module) is the wires that go to the dash, so check engine light, brake input for TC, ALDL connector, A/C input, etc. Take as much of that wiring after the plug as you can get to, and cut it off. Also cut off the ALDL connector with as much wire as you can get with it. That's all you need from the inside unless you're going to take other stuff. On the firewall block side, unhook the block from the firewall and then you're good. Once the wiring is on the bench you can sort those out, but those are mainly power to coil, power to starter solenoid, gauge wires, and your hot all the time and the ignition hot wires to the ECM and sensors. To get it to run, really you just need to hook up the grounds, the oranges to hot all the time and the pink wires to ignition hot. I usually use the original engine wires for the coil, starter, and alternator because they're already tucked up in the loom for me, and I splice them at the firewall. Remember to fuse everything, and if you have the 1227747 ECM you don't need to do any programming for the emissions if you can live without the check engine light being hooked up...but it's always nice to have that stuff turned off if budget allows.

[RootBeer 6117]

Originally Posted by 54 jimmy

thanks Thadious and RootBeer 6117. i could use a diagram that tells me what wires do what so i cam make that determination when the time comes to start this. the motor,wiring,and computer are still in the truck that i am going to get them out of. that won't happen till it gets warmer but it is good to know that i can make the motor stand alone from the rest of the truck.

I wasn't going to send it this way but I cant PM you the pictures if this doesn't work I might have to email you through my regular mail. You can save these to your pictures and then you can enlarge them easier
Joe

[mocajoes]

Originally Posted by RootBeer 6117

I wasn't going to send it this way but I cant PM you the pictures if this doesn't work I might have to email you through my regular mail. You can save these to your pictures and then you can enlarge them easier
Joe

Rootbeer I am doing a similar project. 94 5.7 tbi into a 70 swb 4x4 can I get you to email those schematics to me they are to blury to print off of your post, thanks mocajoes@yahoo.com

[RootBeer 6117]

Originally Posted by mocajoes

Rootbeer I am doing a similar project. 94 5.7 tbi into a 70 swb 4x4 can I get you to email those schematics to me they are to blury to print off of your post, thanks mocajoes@yahoo.com

They are sent,I sent the ones for the engine controls if you more off the truck let me know.
Joe

[jimig1]

I have the pin out in a 1987 Light duty truck wiring diagram booklet from GM. My scanner is not working atm. I will try and work on it and get a scan of it this weekend

[54 jimmy]

any body have a pic of a tbi engine in there ad just to get a feel for how it will look.

[BlueJeep]

It'll pretty much look like a carb'ed motor, with just a few more wires and such on the intake....but it'll run much better than a carb'ed motor.

[Jonboy]

I did the TBI swap into my '74, and it seems to run great (I finished the swap a couple of days before taking it to Vintage air, so it hasn't been driven much). I used the harness from www.fuelinjectionconnection.com as I didn't want to take a chance on 25 year old wiring. The harness was $245, and it was stand alone. There are just a few wires to hook up, and then swapping out fuel lines.

There is a lot of good info on www.binderplanet.com also. A lot of people on there are adapting the GM TBI for use on their IH engines, so there is a lot of info on how to make it work, cleaning up the harness, etc.

[mocajoes]

JonBOY
what year was your tbi? did you use the factory computer?

[Jonboy]

My truck is a '74, but the engine/trans/TBI was from an '87. I used the '87 ECM. I got the long block + all of the accessories, TBI, etc in a box, so I kind of pieced it together with some other parts I had laying around. It came with a TBI spacer, a fuel pressure gauge mounted in the fuel inlet, etc. Since my truck is a '74, I was able to use a factory '87 tank, but an inline fuel pump should do just fine for a TBI setup. There isn't really any need to reinvent the wheel there, all you need is fuel in and a return to the tank. The FIC harness doesn't support any of the emissions, so I eliminated it as well. Here is a link to my build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=433689 and a TBI swap thread: http://67-72chevytrucks.com/vboard/s...d.php?t=317519 . Lots of good info in the TBI swap thread, maybe not as much in my build thread. Hope that helps. There is a lot of good info in the 88-98 section too.