ACT sensor question...

LarsD said:

I haven't ever mounted this thing back into the intake tract since the Explorer lower doesn't have the hole for it. I have it just sitting on top of the intake. If this sensor gets exposed to a lot of hot air would it make the computer richen up my A/F a lot? If not, what affect would it have on my computers settings?

Thanks,
L.D.

Click to expand...

Colder air = richer mixture because it is more dense and therefore has more oxygen.

I mounted mine in the air filter box near the upper radiator hose. A brass fitting from Home Depot can be used to secure it in the air box. Autozone has the crimp pins for the connector if you want to extend the harness. Otherwise you get to cut and splice it in 2 places to make it long enough to reach. Some heat shrink tubing over the new wires and splices make it look like stock.

Uh, jrichker - I think I'm misunderstanding your statement there. You seem to imply that cold air is less dense than warm air - but maybe I'm misreading it. Warm air rises - because it's less dense. Same reason more homeruns are hit in July than in September - less density = less drag on the ball. Cold air is more dense, contains more oxygen - the reason why colder intake air has the potential to make more HP than warmer intake air. But, I think you drew the right conclusion - if the computer is told the air is colder than it actually is, it will try to inject more fuel than it should, making the mixture richer than it otherwise would be. However, the difference is small enough that the once in closed loop, the O2 sensors would adjust it back out anyway. In any event, this time of year, after the engine's warmed up a bit, there's a good chance that having it sitting on top of the lower intake manifold is gonna cause it to read warmer air temps than are actually entering the engine - especially if the engine in question is picking up cold air for the intake. Jrichker's approach for location is a solid one; I mounted mine in the elbow just before the throttle body. PM me with your email address and I'll shoot you a picture of it. Like jrichker - I covered the harness extension with the same corrugated black plastic covering that the rest of the harness is covered with, and you can't tell that it didn't come from the factory that way.

jrichker deserves to inherit my "gettin wired" title. He consistantly gives good advice to people who need wiring help. Hats off to a great fellow stanger.

Ditto....

You fall into the same category Mike - tip of the hat to you too.

does any body know what size tap to use when i go to do mine im gonna put it in the lower and just want to know what size tap to get if i dont have it already! thanks phil

Put the sensor in the air box, anywhere it can "feel" the air that is going into the intake. I have mine sitting on top of my valve cover, until I can find a proper spot for it (I don't have CAI or the stock airbox)

Lars - I took mine to Home Depot with me, bought a bushing that it would screw into; then drilled a hole, and screwed/JB-welded the bushing into the pipe. ACT screws into the bushing for a good, tight fit. I'll shoot you a pic when I get your email address.

Mutual admiration society Tom!

The EGR coolant and the ACT holes are 3/8" National Pipe Thread (NPT) and the 3/8" NPT tap needs a 9/16" drill bit - make sure you get one turned down to 1/2" shaft size to fit in a 1/2" drill motor.

Michael Yount "Uh, jrichker - I think I'm misunderstanding your statement there. You seem to imply that cold air is less dense than warm air - but maybe I'm misreading i"t.

Click to expand...

OOOPs - coldler = more dense - more oxygen. Michael's right... That's what I get for trying to post when I'm not fully awake. Sorry ...

jrichker - now you've put it in a way that I can relate. When partially asleep, I am just like cold air -- more dense.