I have a 1990 toyota 4runner sr5! There is a black and white wire that goes to the starter that has power to it! Half way down this wire there is an encased diode or something and another wire comes up from there to the cold start injector. there is no power to the cold start injector. What r the values of this diode or what can i use in replacement? This does not show up on a wiring diagram!

there is no wiring for trailers
the closest you will get is the diagram for the trailer plugs which shows what wires go to what lights

Pin - 1. Orange 2. Yellow / Red 3. Brown / Black 4. Blue / Orange 5. White / Black

Check Tailgate to Body Contacts--Likely dirty or position problem.

On models without Contact Assembly, wires broken in flex tube ( not easy to spot.)

There is no starter relay on the 1990 camry 4cyl . If you check the fuse panel by the drivers left ankle you will see that there is a socket for a relay but it is missing. On the manual transmission cars it has a relay in that socket. The black and white wire goes directly through the neutral safety switch to the ignition switch.
You can see that same wire on the plug in connection of the starter. If you are having intermittent cranking it is probably high resistance in that circuit, If you are handy just install a relay before the starter connection and have the black and white wire just power your relay coil. The new relay must then be connected to the battery plus and the out put to the plug in wire you cut to install the new relay.

you messed up the ign timing If plug wires are routed correctly Adjust timing to specs.

fun fun fun.
1990 Toyota 4Runner Car Stereo Wiring Schematic
Car Radio Battery Constant 12v+ Wire: Blue/Yellow or Blue/Black
Car Radio Accessory Switched 12v+ Wire: Gray
Car Radio Ground Wire: Brown
Car Radio Illumination Wire: Green
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 4′
Car Audio Front Speakers Location: Dash
Left Front Speaker Positive Wire (+): Pink
Left Front Speaker Negative Wire (-): Purple
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Blue
Car Audio Rear Speakers Size: 5 1/4′
Car Audio Rear Speakers Location: Side Panels
Left Rear Speaker Positive Wire (+): Black
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Red
Right Rear Speaker Negative Wire (-): White

its possible if Ur very careful u need the power wire/ ground and all the speaker wires u can identify these using a multi meter to determain which is the power wire and ground the speaker wires shoul be similair in color like solid brown then a brown with a stripe on it them solid green then a stripped green etc.

the motor is on the transfer case.

The starter on a 4runner is on the LHS of the car at the back botton of the engine on most models. Please give engine details to confirm location.