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What is the thermo vacuum switch?


It's at the front of the thermostat area, with 2 vacuum lines running to it.... controls EGR air supply. The switch can lose value and/or the plastic nipples can crack and leak.

It should not hold a vacuum below 50?F and should hold vacuum above 65?F.

If you have the FSM, run all of the tests shown wrt MPI and Emissions Control - EGR, TPS, MAF etc. Be sure to test the ECT sensor.

Frank

'89 [color:"white"]G-Raider[color:"white"] [color:"black"]Supercharged 3.0L, MegaSquirt 2, lockup A/T, 2.5" exhaust, 172k, Cibie H4s/Oscar SCs, Hella Micro DE fogs, Cobra CB, Superwinch hubs, LSD rear/Aussie Locker front, Bilsteins, Lifeline AGM, Rust-Oleum