The 2 little "sensors" on the ACV. How does this work? When the air blows through it compresses the "sprung rod with the rubber cap" to the bottom of the sensor?

My main problem is that the one that connects into the black wiring melted at the base of the sensor a while back. Is it supposed to compress and close the circuit like an electrical short so to speak? It's hard to find this sensor so i was thinking would it be ok to make a jumper wire to plug into the connector next to the TPS connector? Would that even do anything?

The car just recently failed emissions. I'm pretty sure it's the cat, but the wiring I'm speaking of was intact the last time I tested. Would this possibly cause me to fail emissions?

 

They're not sensors, they're solenoid valves. They're opened by the ECU to increase the amount of air going to the exhaust ports and cat. If you want the broken one to work you'll need to replace it. It would probably be easier to find a complete replacement ACV.

 

But would it be a factor in failing emissions?

 

Possibly, depending on how strict the test is.

 

The rear solenoid is the Split Air Solenoid. It is active ONLY when your in fifth gear. Most if not all emissions test are not done in fifth gear.

The front solenoid is the Port Air solenoid. Opens and shuts at given times. IF you remove it and extract the poppet valve with spring, and put those items in a desk drawer, then reinstall the solenoid, then a little more air will go to the exaust ports than if it were working right.

If you remove the poppet valves out of both solenoids, then your chances of passing emissions has just gone up a tash.

In other words those two solenoids have little effect on passing emissions.

The ACV does most all of it's work thru the two vacuum hose coming from the RElief and Switching solenoids on the other side of the engine. IF those two hose and solenoids are not connected up and working right, then the ACV will not put the airpump air to the exaust ports when needed. If I were you I'd read the Fuel seciton of the fsm and check out the ACV plus Relief and Switching solenoids per that simple manual.

In other words the two solenoids you mention play a very minor part in emissions testing. But the ACV itself is very important.

Never hurt to have a good catalytic converter to go with it.

Plus a properly set tps interacts with the switching and relief solenoids to make them operate at the right time.

 

this is good info.

i set my TPS after i put a new UIM gasket on and new injector O rings etc. it wasnt really off to begin with. Idle is at 800 RPM. The numbers were 3 times over the legal limit so my first thought was the catalytic converter. O2 sensor is 3 months old. The exhaust smells like gas and seems to have lost a bit of low end torque since I bought it over a year ago. Those are 2 symptoms of a clogged up cat if im not mistaken.

 

on the fuel injected cars the air pump air going to the exhaust ports, and a good o2 sensor are the most important things. you need a cat too, but it doesnt have to be that great.

 

well i tested 3 times over the limit for 2 things... so im pretty sure the cat isnt doing its job. i can get a direct bolt on for $89 from o reileys so no big deal. it should free up a slight bit of MPG and power as well. might even sound better.

 

Also keep in mind that the air supplied to the rear portion of the main cat is there for a very important purpose.....to allow the cat to complete the chemical conversion of pollutants and unburned fuel into less harmful ones. The cat can actually self-destruct when the extra oxygen isn't present. I have cut open a few clogged cats and found the honeycomb substrate actually fused together from intense heat, so it makes perfect sense that the extra oxygen would positively affect tailpipe emissions.

 

im working on getting a new solonoid and cat so it should be all good soon,