It could be a couple things. Here are the directions for testing the injector. The attached pictures correlate with the directions.
1997 Toyota Truck 4 Runner Limited 4WD V6-3.4L (5VZ-FE)
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Injector Testing and Inspection Component Tests and General Diagnostics Injection Inspection
FUEL INJECTOR INSPECTION
1. Inspect injector resistance.
Using an ohmmeter, measure the resistance between the terminals.
Resistance: At 20°C (68°F): Approx. 13.8 ohm
If the resistance is not as specified, replace the injector.
2. Inspect injector injection.
CAUTION: Keep injector clear of sparks during the test.
(a)Disconnect the fuel inlet pipe from the fuel tube.
(b)Connect SST (attachment and hose) to the fuel tube. SST 09268-41046 (09268-52011)
(c)Connect the fuel return hose, SST (union) and SST (hose) to the fuel pressure regulator. SST 0926841046 (0926841091)
(d)Install the 0-ring to the injector.
(e)Connect SST (union and hose) to the injector, and hold the injector and union with SST (clamp). SST 0926841046
(f)Put the injector into the graduated cylinder.
HINT: Install a suitable vinyl hose onto the injector to prevent gasoline from splashing out.
(g)Connect the TOYOTA hand-held tester to the DLC3.
(h)Connect SST (wire) to the injector and battery for 15 seconds, and measure the injection volume with a graduated cylinder. Test each injector 2 or 3 times. SST 09842-30070
Volume: 55 - 70 cm. Cube (3.3-4.3 cu. In.) Per 15 sec.
Difference between each injector: 6 cm. Cube (0.4 cu. In.) Or less
If the ignition volume is not as specified, replace the injector.
3. Inspect leakage.
(a)In the condition above, disconnect the test probes of SST (wire) from the battery and check the fuel leakage from the injector. SST 09842-30070
Fuel drop: 1 drop or less per minute
(b)Turn the ignition switch to LOCK.
(c)Disconnect the negative (-) terminal cable from the battery.
(e)Disconnect the TOYOTA hand-held tester from the DLC3.
Let me know what you find or if you have other questions. Also, if you have a live data scan tool, let me know what the short term fuel trims are.
Take care and God Bless,
Images (Click to enlarge)
Sunday, February 7th, 2021 AT 7:43 PM