question about a tbi 350

[tree_bashed_sammy]

i put a tbi 350 in my toyota truck heard it run before they pulled it out of the subarban. put a holley inline fuel pump in it well the wiring was junk couldnt get no power threw it so i got another wiring harness and got power to everything but the injectors so i got another computer and still no injector pulse ran all new grounds nothing changed the module in the dist cap nothing anyone have a clue what i can do now? im clueless thanks for any input

im just wanting power to motor i dont need no power in the cab or lights or anything im about to try to find someone to make me a new wiring harness for just what i need if i cant figure it out

[jlynch]

From the factory, the injectors get power from a relay. Do you have the relay hooked up properly? The ignition module in the cap is on a seperate relay. You should have got two relays with your harness. All of your answers can be found at the site below. There is a printout on the wiring harness that tells you what each wire is and what you need to do with it. It is not that difficult to hook up the wiring with it. I have installed 3 of them using it.

http://www.binderplanet.com/forums/forumdisplay.php?f=75

[93 Krawler]

I would hook a scanner to the ALDL port and see what is going on. I've seperated a few EFI harnesses and it sucks. If you can't find a good harness and seperate what you need, then just get a Painless wiring harness.

[93 Krawler]

What year TBI are we looking at? Mine is a 93 and it only has 1 relay for the fuel pump.

[jlynch]

What year TBI are we looking at?

I guess that would be useful information.

You don't have to have 2 relays depending how you wired it up, but the ignition will either need to be on a relay or on a switched 12 volt source.

[93 Krawler]

On my 93, one side of the injectors goes to the fuse block and the ECM, and the other side goes to the ECM in two spots for the pulse. I'd make sure the ECM ground is hooked up. Mine is blk/wht. There's not much that would keep the injectors from not working.

[jlynch]

So to start out we will go right down the line in order.

A1- grn/wht- this wire is used to energize the fuel pump relay.
A2- not used
A3- not used
A4- gry- to EGR relay.(optional) This is a ground from the ECM to control the EGR relay.
A5- brn/wht- SES(service eng soon) light. This is a ground to turn on the light.
A6- pnk/blk- switched 12v from the ignition relay.
A7- not used
A8- orn- ALDL Serial data. This is your ALDL pin E data for your lap top.
A9- wht/blk- ALDL pin B diag mode. When jumpered to ground will set the ECM to ALDL diagnostic mode.
A10- brn- VSS speed sensor signal to the ECM (optional)
A11- ppl or blk- MAP sensor ground. See ECM ground thread.
A12- blk/wht- System ground. Can be tied with D1. Goes to engine ground.

B1- orn- 12v fused from battery. I use an inline fuse on this. It also ties into C16.
B2- tan/wht- Fuel pump signal from the relay. This one ties into several places, the fuel pump, the relay, and the ecm. When the relay is on it sends 12v thru this wire to turn on the fuel pump, at the same time it tells the ECM the fuel pump is on.
B3- blk/red- EST reference.
B4- not used
B5- ppl/wht- EST high reference
B6- not used
B7- blk- ESC signal This is the knock sensor signal to the ECM. The knock sensor circuit is optional. If not used, tie this wire to C14 the 5v reference.
B8- dk grn- AC signal. This tells the ECM that the AC is turned on. This can be used to set the idle speed higher when you turn the AC on. I use it to increase the idle when using the compressor for on board air. Same thing!! Just tie it to the wire going to the AC clutch.
B9- not used
B10-orn/blk- Park/Neutral sw. This is optional but I have hooked it into the park sw on the tranny. It tells the ECM when you are in Pk or N. It can be used to give a slight adjustment to idle speed when switching from park to drive and back.
B11- not used
B12- not used

C1- not used
C2- not used
C3- IAC- Idle air control
C4- IAC
C5- IAC
C6- IAC -The ECM controls the IAC motor. It adjust the amount of air that is bypassed around the butterflies to adjust the idle speed.
C7- not used
C8- not used
C9- ppl/wht- Starter crank signal. Goes to the small terminal of the starter. The stock scout wire is white that goes there. Tells the ECM you are trying to start the engine.
C10- yel- Temp sender signal
C11- lt grn- Map sensor signal
C12- not used
C13- dk blu- TPS sensor signal
C14- gry- 5v reference signal to map and TPS.
C15- grn- inj B ground signal. Most systems do not use this. It was used on some of the bigger engines to share the load of the injector signal.
C16- orn- fused 12v tied to B1

D1- blk/wht- System ground, ties to A12 and engine. See ECM ground thread.
D2- blk- Sensor ground. To eng.
D3- not used
D4- wht- EST control
D5- tan/blk- EST bypass. This is the wire that has a plug near the distr that you disconnect to set your timing.
D6- Tan- O2 ground to engine.
D7- ppl- O2 sensor signal
D8- D13 not used
D14- lt grn- Injector B ground signal
D15- blu- optional injector A ground signal
D16- blu- Injector A ground signal
And that's it.
If you sit down on your garage floor and have each sensor plugged into the harness, then trace each wire back to the ECM connector, you will be able to separate a lot of uneeded wires.
Once you have each wire identified and layed out, then you can set it up on the engine and start tailoring it to fit your engine.
Placement of the sensors will determine wire length. Most stock harnesses are plenty long and only need to be shortened or wrapped and bundled.
When I'm all done and it's running then I go back and reinstall the plastic loom over all the harness.

[93 Krawler]

That is different than mine. Here is the full size image. http://cincilocal.com/0996b43f80231a23.gif

[bizeeb65]

I had the same problem when I installed TBI on my SBC. The injectors require 12v when cranking direct from a fused, key on source. I didnt have this hooked up.

[jlynch]

Here is a good diagram

4456

[tree_bashed_sammy]

its a 90 thanks for the help i will try and see what i can do with this info

[tree_bashed_sammy]

Ok i cant figure out this wiring problem does anyone no where i can take it and have it done im clueless on it at this point. Thanks david

[sarge]

one of the Miami Valley Four Wheelers is a TBI swap god ! I can't recall who but post up on their site and I'm sure one of them will point you in the right direction .

[jeepmanjeff]

I can work on them. I have done several myself. Give me a call and we can discuss. 513-250-7941

[tree_bashed_sammy]

Ok jeepmanjeff ill give u a call tomorrow if i can