Tbi swap build thread

[cjracing15]

Ok here are all the pin outs and the color of the wires. My computer is the standard #1227747

A1- grn/wht- this wire is used to power the fuel pump-relay.
A2- no wire
A3- no wire
A4- gry- to egr-relay. This is a ground for the ECM to control the EGR relay.
A5- brn/wht- service soon light. This is a ground to turn on the light.
A6- pink/blk- switched 12v from the ignition relay.
A7- no wire
A8- ornange aldl serial data wire pin-e
A9- wht/blk-aldl pin B When jumpered to ground will set the computer to diagnostic mode.
A10- brn- VSS speed sensor signal to the computer, (This wire I will wire this to on side of a after market VSS sensor and the other wire on the sensor goes to ground).
A11- blk- MAP sensor ground.
A12- blk/wht- System ground. This wire is tied to other grounds in the harness and goes to engine ground.

B1- orn- 12v batt power ( I looked and traced down this wire on my 87 cab harness and this is fuesed I think it was a 15). I will probably use a inline fuse.
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 12 volts to trun on the fuel pump.
B3- blk/red- Distributor plug
B4- no wire
B5- purple/wht- Distributor plug
B6- no wire
B7- blk- ESC signal This is the knock sensor signal to the computer.
B8- dk grn- AC signal. This tells the ECM that the AC is turned on. I am going to tie this into the ac clutch wire.
B9- no wire
B10-orange/blk- park neutral switch wire. some people say this is optional but I do not think it is because it gives a signal to the computer to give the engine a slight bump in rpm.(if you don't need it why did they put it there?)
B11- no wire
B12- no wire

C1- no wire
C2- brn- wire is not needed
C3-grn/blk- Idle air control
C4-grn/wht- Idle air control
C5-blue/wht- Idle air control
C6-blue/blk- Idle air control C3-C6 all go to the Idle air control valve plug on the TBI it's self.
C7- no wire
C8- no wire
C9- purple/wht-Starter crank signal wire. Goes to the small terminal of the starter.
C10- yel- Temp sender
C11- lt grn- Map sensor
C12- no wire
C13- dk blu- throtle position sensor
C14- gry- signal to map and TPS. ( you will see it tied together in the harness)
C15- on wire
C16- orange- This wire is tied with B1 so it is a 12volt wire

D1- brn/wht- system ground goes to the engine.
D2- blk- tied to the wires for the engine ground.
D3- no wire
D4- wht- distrbutor plug
D5- tan/blk- distrbutor bypass. This is the wire that you disconnect to set your timing.
D6- Tan- O2 sensor ground to engine.
D7- purple- plugs in to the o2 sensor
D8- D13 no wire
D14- grn- Injector plug plugs into the top of injector
D15- no wire
D16- blue- Injector plug plugs into the other injector

[cjracing15]

Originally Posted by cjracing15

Ok here are all the pin outs and the color of the wires. My computer is the standard #1227747

A1- grn/wht- this wire is used to power the fuel pump-relay.
A2- no wire
A3- no wire
A4- gry- to egr-relay. This is a ground for the ECM to control the EGR relay.
A5- brn/wht- service soon light. This is a ground to turn on the light.
A6- pink/blk- switched 12v from the ignition relay.
A7- no wire
A8- ornange aldl serial data wire pin-e
A9- wht/blk-aldl pin B When jumpered to ground will set the computer to diagnostic mode.
A10- brn- VSS speed sensor signal to the computer, (This wire I will wire this to on side of a after market VSS sensor and the other wire on the sensor goes to ground).
A11- blk- MAP sensor ground.
A12- blk/wht- System ground. This wire is tied to other grounds in the harness and goes to engine ground.

B1- orn- 12v batt power ( I looked and traced down this wire on my 87 cab harness and this is fuesed I think it was a 15). I will probably use a inline fuse.
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 12 volts to trun on the fuel pump.
B3- blk/red- Distributor plug
B4- no wire
B5- purple/wht- Distributor plug
B6- no wire
B7- blk- ESC signal This is the knock sensor signal to the computer.
B8- dk grn- AC signal. This tells the ECM that the AC is turned on. I am going to tie this into the ac clutch wire.
B9- no wire
B10-orange/blk- park neutral switch wire. some people say this is optional but I do not think it is because it gives a signal to the computer to give the engine a slight bump in rpm.(if you don't need it why did they put it there?)
B11- no wire
B12- no wire

C1- no wire
C2- brn- wire is not needed
C3-grn/blk- Idle air control
C4-grn/wht- Idle air control
C5-blue/wht- Idle air control
C6-blue/blk- Idle air control C3-C6 all go to the Idle air control valve plug on the TBI it's self.
C7- no wire
C8- no wire
C9- purple/wht-Starter crank signal wire. Goes to the small terminal of the starter.
C10- yel- Temp sender
C11- lt grn- Map sensor
C12- no wire
C13- dk blu- throtle position sensor
C14- gry- signal to map and TPS. ( you will see it tied together in the harness)
C15- on wire
C16- orange- This wire is tied with B1 so it is a 12volt wire

D1- brn/wht- system ground goes to the engine.
D2- blk- tied to the wires for the engine ground.
D3- no wire
D4- wht- distrbutor plug
D5- tan/blk- distrbutor bypass. This is the wire that you disconnect to set your timing.
D6- Tan- O2 sensor ground to engine.
D7- purple- plugs in to the o2 sensor
D8- D13 no wire
D14- grn- Injector plug plugs into the top of injector
D15- no wire
D16- blue- Injector plug plugs into the other injector

This might help also if you don't have it. It is on the first page of this thread. Again good luck.

[rfmaster]

Pancake

Looks like you are digging into retrofit - full speed ahead

For P/N switch functionality you'll have to wire a small, simple circuit which requires some wire (12 AWG purple and 16AWG, 1/4" crimp connectors (female and male), BOSCH 30 amp relay, and silicon diode 1N4001 - Radio Shack.

Questions???

//RF

[pancake]

Ok...almost ready to put the tbi on my Blazer.....but have another question. I understand the wiring for P/N switch but do I NEED this for a manual tranny?

again, thanks for all the info and advice.

[rfmaster]

pancake

To get things going it is not required, but having a neutral position sense switch will improve driveability (i.e. ECM alters idle and timing somewhat (depending on ECM, other parameters as well - EGR operation, AIR) between neutral position and being in gear.

Leave B10 (orange-black) unconnected for now (this way ECM will see that truck is always in gear).

//RF

[pancake]

Sorry if this is a repeat post, The other one did not look like it was posted.

Almost ready to install but had a few more questions:

My Oil Pressure Switch has three wires coming off it: orng, gry, and light tan. I know where the orng and gry wires go but where does the light tan wire go?

To install Dizzy do I need to find TDC on #1 and install dizzy so rotor points at #1 plug wire?

What should I start with for timming for a TBI 5.7L?

I need to disconnect a wire to set timming? D5 lt brn/blk wire?

Any advice on timming or insatlling the Dizzy would be great.

Thanks again for all the help and I hope people are getting some usefull information from this thread!

[rfmaster]

Originally Posted by pancake

Sorry if this is a repeat post, The other one did not look like it was posted.

Almost ready to install but had a few more questions:

My Oil Pressure Switch has three wires coming off it: orng, gry, and light tan. I know where the orng and gry wires go but where does the light tan wire go?

Orange is battery side of FP supply circuit, gray is the fuel pump (FP) side of the circuit. Tan wire goes to oil pressure gauge (depending on switch part number it can be gauge or oil pressure light)

Originally Posted by pancake

To install Dizzy do I need to find TDC on #1 and install dizzy so rotor points at #1 plug wire?

Yes, you need to find #1 Cylinder TDC and corresponding dizzy post.

Originally Posted by pancake

What should I start with for timming for a TBI 5.7L?

0 TDC with EST connector open is a standard for truck TBI.

Originally Posted by pancake

I need to disconnect a wire to set timming? D5 lt brn/blk wire?

You should have a single wire weather pack connector - usually it is light brown with white or black stripe. Try to get your engine going first, then set the timing once it warms up. 0 TDC is the number. With EST connector open ECM will set code 42 - this is perfectly normal. Clear it by disconnecting battery after shutting engine.

Originally Posted by pancake

Any advice on timming or insatlling the Dizzy would be great.

Thanks again for all the help and I hope people are getting some usefull information from this thread!

Before taking original dizzy out remove hat and turn engine by hand until balancer reads 0 TDC and mark and rotor points toward #1 on dizzy. Mark that location before removing dizzy from intake. As you pull dizzy out the rotor will turn counter clockwise. Mark the final position as well. The idea here is to pre-align TBI dizzy so it just drops in place of HEI. Otherwise, turn engine to the 0 TDC and with a help of 12" BFS turn oil shaft as shown in the figure below. The key is to have oil pump shaft slot to line up with #5 Intake rocker (approximately). Turn TBI dizzy counter clockwise so as it drops it will turn clockwise and engage oil pump shaft. Whoa la!