What is the e1 and te1 terminal - 1991 Toyota 4Runner

The 2.2L of that year would be the 5S-FE engine.
It used an electronic Idle Speed Control Valve.
With all of the intake/vacuum system connected connected, accessories off and the transmission in neutral connect a tachometer. Short terminals TE1 and E1 of the underhood check connector.
Wait for the idle to maintain 1000-1300 RPM for 5 seconds.
If needed adjust the idle adjust screw to an engine speed of 650+-50 RPM.

US Idle is 700+-50 RPM, CA M/T is 800+-50 RPM and CA A/T is 750+-50 RPM.

Remove jumper of E1 and TE1 of the check connector.

O/D light flashing indicates a fault in the transmission. Manuall diagnose by bridging terminals Te1 and e1 on the diagnostic socket. refer to repair manual on the code got.

Connect terminal TE1 and E1 as here, p 296

http://www.turboninjas.com/camry/eg1.pdf

Ignition Timing
w/ Terminals TE1 and E1 connected of DLC1.
8 to 12 deg BTDC
at Idle

Hello. Welcome to FixYa. Please allow us to assist you.

To access the OBD codes without a scan tool:

Open the hood.

Locate the samll grey plastic box mounted under the hood

Open the small box, and look under the lid locate terminals E1 and Te1.

With a small paperclip, insert one end into cavity E1 and the other end into cavity Te1

Turn the key on

Count the blinks of the check engine light. Example 2 blinks pause 4 blinks would be code 24.

After you have the code(s), please get back to us for further information.

Thanks for choosing FIxYa. Have a great day.

2,4 engine : 5° 700-750 rpm. but before you adjust timing, you need to bridge terminals TE1 or T1 with E1 of check connector. bridge should be removed after adjusting.
hope it helps
Marko

igntion timing?
Note: w/Terminals TE1 and E1 connected of DLC1. 8 to 12 deg BTDC
Note: at Idle

TC and the E1

you will need to connect a wire from the "TE1" terminal and the "E1" terminal in the dlc box under the hood. timing should be 8-12 BTDC...I'm not sure if a scanner needs to be connected when checking timing.

Open the hood. Locate a small grey box by the firewall, roughly 1.5 x 1.5 inches. It has a cap that will lift up, but it will not come off. Under the cap, located the terminals E1 and Te1. Using a standard paper clip, "jump" E1 and Te1 together. Turn the key on. Obnserve the check engine light; it will flash, pause and flash again. Count the flashes.
Examples: 2 flashes/pause/4 flashes is code "24"
1 flash/pause/5 flashes is code "15"
Get the codes & get that info back to me so that I will be able to assist you with your issue further.