Sorry for the very vague title. Anyway I was working on my car today and noticed that when I was finished and started the engine up that it was smoking from under the hood. I quickly shut the engine off and sure enough there was a small flame on the passenger side. As you can see in the picture, the wire and the solenoid that it was attached to were melted. I am wondering exactly what this wire does and if it is really needed. Yes I still have the air pump and emmission on so I can not block the entire unit off. Oh and if anyone has an extra one for sale hit me up! Thanks

 

i believe thats your air control valve (acv), what year is your car ? i

 

*nods* Air control valve. It's a fairly important part of the emissions equipment, it redirects air to the cats as needed.

I probably have a few laying around. I'll also be passing through Aurora on the way to Downers Grove next weekend.

More importantly, do you know WHY your engine started on fire? I'd be more concerned about that right now.

-=Russ=-

 

I take it your Split Air Solenoid on the ACV burnt up due to the wires being shorted out. Unscrew one from a acv in the wrecking yard and install it. Odd that you didn't mention a fuse being burnt out.

 

yeah it shorted out, though I havent found a burnt out fuse. Thanks guys

 

Hailers, you've been around on the forum a lot longer than me, how many of these solenoids have burned up over the years? It seems like one every two weeks or so since I've been on...

The question is WHY are they burning up? Is it just old wiring right at the plug back that tends to break and short?

Is it an old coil in the solenoid shorting out and drawing excessive current?

Why do they seem to short out at idle while the car's sitting still? They shouldn't be energized at that point...

Is it something that fritzes out in the ECU that grounds that solenoid forever and ever, causing it to remain energized as long as the key is on, which leads it to a shorted death?

So many questions, so few answers...I'll expect a full report on my desk by noon tomorrow...

 

Try this. Unscrew the Split Air Solenoid. Don't drop the small spring and poppet valve. Now unscew the Port Air Solenoid on the front of the acv. Swap the two solneoids.

The Port Air Solenoid is disabled after 20,000 miles so there's no loss there. The only thing you will HAVE to do now, is extract the two wires out of the Port air solenoid and install the PLUG for the Split Air Solenoid on those two wires. You do this so you can connect the NEW Split Air Solienoid to its mating connector. Make sense. Does to me. You? Or how about YOU NEED TO SWAP THE PLUGS B/T THE PORT AIR SOLENOID AND SPLIT AIR SOLENOID PRIOR TO SWAPPING THE TWO SOLENOIDS. The two plugs are different and won't mate right unless you do that.

Why do the wires short? How about someone unscrewing one of the solenoids and letting the wires twist 'round and 'round and 'round??????????? Yeah. That's it.

 

I don't buy it...For one, there's no reason to ever remove those guys during the normal life of the car (except for guys that tinker, such as yourself).

And second, who in their right mind would let the wires twist up while they were wrenching on the solenoid?

Personally, I like the "ECU is perpetually grounding the solenoid" theory. Yep, that's my favorite...It also neatly explains why the fuse isn't blowing...

 

Disabled after 20k? Can someone explain that?

Edit: Ok, I just found this, interesting and still confused.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/port-air-solenoid-453736/

 

Yes. It's written in the online factory service manual. It's for allowing more air into the exaust ports during the first 20,000 miles to help keep the emissions cleaner.

If you want you can leave the poppet valve out and have it supply air anytime your running. That's EXTRA air to go along with the rest of the air from the airpump to the exaust ports. EXAUST PORTS, as in the exaust ports on the enginej just before the exaust manifold.

In other words it never again receives a ground signal from the ECU after 20,000 miles (with exceptions to the rule). It take a gnd signal to open them. 12vdc is always there with the key to ON or better.