Help me identify these!
 

My engine bay has a bunch of things that are either not connected, or hanging loose. I NEED to find out what its all for. Car runs great and everything as/is, but I feel it could be better. Below are some pictures I took of various things I found:

http://www.rx7page.com/rx7/rx1.jpg
http://www.rx7page.com/rx7/rx2.jpg
On the pic above, the box on the right isn't connected to anything (but has a vacuum hose attached).
http://www.rx7page.com/rx7/rx3.jpg

The pic of the sensor is the one that concerns me. I can't figure out where it goes, it was just tucked under the intake manifold. Maybe its not important but I don't know. Btw.. this is an '86 GXL.

Top pic:

Injector resistor box

Middle pic:

Pressure sensor.

Bottom Pic:

ACV Solenoid minus the plunger and spring.

Rat

Ok.. since I don't have the ACV anymore, i'll ignore that one. But are the other ones important at all? I couldn't even find the plugs that were supposed to go into them.

Well, if your car is running and the injector box is disconnected, that leads me to believe that at some time or another, your car was either retrofitted with an 87.5 or later ECU, OR you are on a standalone of some sort. Because if you needed that box, your car wouldnt run. I could get into specifics on that, but I would rather not.

As for the pressure sensor, as long as you are on a stock harness, you really NEED that box hooked up. Again, my guess is it got disconnected some time ago because your car may have devoloped the 3800 RPM stumble. So, having said that, its time to bust out the trusty FSM, and get the vacuum line and plug put BACK in that pressure sensor.

Rat

*edit*.. I need some sleep..

The engine is not original, and the previous owner had to put in a different ECU due to the injectors, so that must be why. The pressure sensor on the LEFT in that pic is hooked up properly, its the one on the right that isn't. It has the vacuum hose attached to it, but there is no plug sitting around that fits in there.

The one on the left is some type automatic transmission bull shit sensor. The one on the right is the Pressure/Boost sensor/MAP sensor. Look up the definition of MAP sensor and see if it's really needed. Or the JRAT might know. PM him relentlessly.