TVSV and drivability

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NWMO
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Re: TVSV and drivability

Post by NWMO »

Hey all,

For those looking for one of these in the junkyards, I found one with my 4a engine from an 85' Chevrolet Nova. They are mounted in a hose that runs right above the flywheel end of the engine, appears to be identical component.

Chris
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The Professor
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My tercel:: 1987 Tercel SR5 4WD wagon
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Re: TVSV and drivability

Post by The Professor »

Good looking out! Thanks!
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stanrob
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My tercel:: Two 1985 Tercel SR5 4WD, Cal. emission controls, one now a parts car (good engine & transmission, still had full power at 310K), another, a low-rust project car, with 307k miles, from Petros
Location: Wayland, MA, USA

Re: TVSV and drivability

Post by stanrob »

Before I take a dive and reimburse xirdneh his $100 price for a new TVSV, I need to eliminate the possibility that a good used TVSV is available. I've just written Petros about his collection, but what about the rest of you guys?

It needs to be vacuum-leak-free and also to pass the tests on FSM page EC-22. The first one I found right here was vacuum-leak-free but it failed those tests.

After more study, it's become clear to me that the TVSV has to work right for cold-engine drivability. As page EC-54 shows, the auxiliary acceleration pump (AAP) is actuated by vacuum directly from the TVSV. No vacuum means no AAP actuation. But the sole raison d'etre for the AAP is cold-engine drivability.
xirdneh
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Re: TVSV and drivability

Post by xirdneh »

stanrob wrote: Fri Feb 02, 2018 9:54 pm Before I take a dive and reimburse xirdneh his $100 price for a new TVSV,
i'm not the one selling the TVSV

i have an all brass TVSV that i found somewhere. it has no plastic. the upper portion with the ports is all brass.
have not tested it yet. i am going to use it on the next tercel i work on that needs it
Love those Tercell 4x4 wagons but they sure suffer from road noise.
stanrob
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Posts: 106
Joined: Thu Aug 30, 2012 3:03 pm
My tercel:: Two 1985 Tercel SR5 4WD, Cal. emission controls, one now a parts car (good engine & transmission, still had full power at 310K), another, a low-rust project car, with 307k miles, from Petros
Location: Wayland, MA, USA

Re: TVSV and drivability

Post by stanrob »

Oops, I should have remembered it was irowiki who had the brand new one.

While looking back at my meandering posts, I believe my choke actuation theory was insufficient to explain what's going on. More thinking, plus looking back at others' posts, persuades me that AAP non-actuation is probably the really important part. This is underscored by our colleague's reporting (far above) of a jerk encountered in the course of applying power when fully warmed up. His faulty TVSV was transmitting manifold vacuum to the AAP. This would be sort of a mirror view of my no-vacuum situation.
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