What is Air Injection state at idle

[sue]

Does anyone here know what the state of the air injection system should be at idle? Should VSV(1) and VSV(2) both be open at idle?

I have the 2F emissions manual but it doesn't seem super clear to me. Any help would be appreciated.

 

[bhk]

At idle, VSV(1) should be open, VSV(2) should be closed and air is injected into the exhaust ports.

 

[sue]

At idle, VSV(1) should be open, VSV(2) should be closed and air is injected into the exhaust ports.

View attachment 1448394

Okay, that's what I thought. My next question then is what would cause both VSV(1) and VSV(2) to be open at idle? VSV(2) is open for some reason and this is what's driving me crazy.

From what it looks like it would be a problem with the fuel cut system, but my fuel cut system checks out fine from the emissions manual tests. Connection on the vacuum switch seems good. I thought maybe it could be a problem with the computer, but does the computer stay in the "on" position if it is broken?

 

[sue]

Test to make sure that VSV2 actually works & isn't stuck open (broken). With the engine off, try to blow air through it. If air does blow through it, it's defective.

More than one input can occur for the emissions computer to trigger VSV2. You've ruled out one of them testing the vacuum switch. You can test the cat temp probe according to the FSM and it's doubtful the coil trigger is faulty.

If your test for VSV2 shows that it's good, then the suspect is the emissions computer.

If you're interested in passing a smog test, the vacuum hoses to the ACV can be routed to ensure air gets injected to the air injection manifold regardless if vsv2 is working or not. The vacuum hoses going to the ACV can also be plumbed (& plugged) so the ACV diverts air to the exhaust pipe instead.
During a smog test, it's best to have the air injected into the ex ports via the air injection manifold... If it's check valve flows air freely.
(but then again... there's a member here that could only pass with the air diverted to the ex pipe....so who knows?).

Okay, I wasn't sure exactly what triggered it other than the vacuum switch or how the electrical bit was set up. This makes sense, I'll test the thermo sensor since I haven't yet.

I'm interested in passing a smog test, but I first want to try it with the emissions system working properly.

 

[sue]

In case anyone else ever has this same weird problem:

Turns out some previous owner or mechanic had directly grounded the VSV(2), so it wasn't going to the computer at all.

Re-wired it and now everything works fine.