June 17, 2021
The throttle body was cleaned up by hand, I tried to remove and clean up each part the best I could as well as each port (make sure to check back of TB for clogged ports). Also, I have a PO401 code I am hoping to clear with the new hoses and the TB cleaning. I as well changed out the VSV and all of the vacuum/ heater hoses under the manifold including a molded one for the EGR I went into Toyota to get. I skipped out on the heater hose which comes out of the TB and runs down into the block near the PHH but replaced the one which runs into the TB. I got some new drive belts for ac and alternator, I tightened them up to have about 1/2" of deflection. Gave a couple of goes at removing the EGR valve itself but no luck, so I decided to save it for when I replace the heater valve and hoses behind it so I'll have more clearance. More info on PO401 here-
80 EGR VSV Replacement - https://forum.ih8mud.com/threads/80-egr-vsv-replacement.317230/
Testing:
INSPECT EGR VACUUM MODULATOR OPERATION
(a) Block ports P and R with your finger.
(b) Blow air into port Q, and check that the air passes through to the air filter side freely.
(c) Start the engine, and maintain speed at 2,500 rpm.
(d) Repeat the above test. Check that there is a strong resistance to air flow. If operation is not as specified, replace the EGR vacuum modulator.
RECONNECT VACUUM HOSES TO EGR VACUUM MODULATOR
(a) Connect the vacuum hose to R port.
(b) Connect the vacuum hose to Q port.
(c) Connect the vacuum hose to P port.
P and R are the ports right next to each other. Q is the single port that goes to the egr.
Hoses:
• Vacuum Hose (90999-92003) x 6
• EGR modulator hose(25695-66010)
EGR
• EGR modulator (25870-66011) *if you can you did not pass test above)
• Vacuum Switching Valve VSV(90910-12079
)
Belts:
• Alternator (90916-02353-83)
• AC belt (99332-10910-83)