ACT Sensor location '90 vs '95

[cwtoyota]

Working on an engine installation.

Using a 1995 5.0L Mustang GT engine and sensors.

Using a 1990 A9L computer and harness.

On the 89-93 cars the Air Charge Temperature sensor (ACT) is located
in the lower intake manifold.

On the 1995 car, the ACT sensor is located in the intake piping between the throttle body and MAF sensor.

The air in the lower intake manifold may be somewhat hotter than the air in the intake piping before the throttle body.

The 1995 intake is not drilled/tapped for the sensor. If I run the ACT sensor in the 1995 location with the 1990 computer? It seems that the computer would advance timing, and enrich fuel for the slightly colder air signal.

Will this create any problems or can I just run it?

 

[ID89GT]

If you can put it in the air intake tubing that can work. I have a BBK cold air so I had to have the intake tapped. Only cost me 20 dollars for mine to be done. If it were me I would just get it tapped, or just find an intake lower already tapped and ready to go.

 

[cwtoyota]

I have several intakes uppers/lowers, etc. I just didn't want to change it out right now. I wanted to port an intake and throw it on later with a set of heads all at the same time. right now I'm busy working on the fuel system, cooling system, exhaust, etc. ...Engine swaps...

 

[joncash]

It is a common upgrade for 94-95 owners to retrofit an A9L/A9P computer to their car without changing the engine harness or intake manifold soooo...puttting the ACT sensor in the intake tract before the throttle body w/ a Fox ECU is nothing that hasn't been done on many street cars before.

The car will probably run better. The reading will be more accurate because it won't be influenced by the hot engine, and the computer will stay in its more aggressive mapping as a result, which means the car's power will be more consistent.

If you run premium gasoline and keep the initial timing at something sane (14-15 degrees btdc) there should be no problem at all.

Plus you live in Washington, you've got a "cold air advantage" over those of us in the South . Take advantage man, take advantage.

 

[cwtoyota]

Thanks JonCash, that's what I wanted to hear, however sometimes things are 'funny' when you start swapping them around. I called Ford's tech hotline today and they said the same thing, it will work just fine.


I just finished modifying the 1990 engine harness to work with the intake mounted IAT sensor, a Toyota oil pressure sensor, and a few other changes to better suit my combination.

 

[jrichker]

The next best spot for the ACT is the stock air box if you don't do the drill and tap thing. You get to cut and splice the 2 ACT wires in order to make them long enough to reach the air box. Solder the wire extensions on the existing wires & use heat shrink tubing to cover the splices. Offset the place where you cut the wires so that you don't have a big bulge when you put heat shrink over the 2 wires to cover & protect them. The air box gets a hole (5/8" or so) for the ACT drilled about 1 1/4" down & 1/1/4" in on the front top side near the upper radiator hose. A brass fitting nut from Home Depot or Ace Hardware secures the ACT into the air box.

If you are very clever, you will find that the ACT connector comes apart so that you can remove the pins. A very small screwdriver releases the lock in the front of the center insert, while another small screwdriver inserted in the back pushes it out. Once the center insert is out of the connector shell, the pins come out easily. New pins are available from AutoZone in a $5 electrical pin kit for Fords. Crimping the pins on the extender wires saves you from having to splice them twice: once to put the connector on and once to extend the wires.

6 ft black 18 gauge wire
6 ft green 18 gauge wire
6 ft 1/4" heat shrink tubing
1 ft 3/16" heat shrink tubing

Measure the 2 extender wires & cut them to length, crimp one set of pins on them. Then mate up the extender pins with the wiring harness & slide the 3/16" heat shrink tubing over them & shrink the tubing. Then slide the 1/4" heat shrink tubing over the pair of wires and shrink the tubing. When you are done you'll have about 1" of wire left without heat shrink tubing on it to strip & crimp the new pins on. Stick the new pins in the old connector shell, assemble it and you are done. It looks as good as factory. Some wire loom can be used to enhance the "Factory Look".

 

[cwtoyota]

jrichker, good info all around.

I've done the modifications to the wiring harness for this and the '95 style TPS which uses an oval plug instead of the 88-93 round plug. I use this green fiber insulating sleeve that I picked up at Boeing surplus a few years back with a short adhesive lined heat shrink at each end. It's heat resistant and extremely strong. I think it's the same stuff used around the wires on the Bosch HEGO sensors without the slick silicon coating. It's called "Varflex" and it came in 100 foot rolls with a leader string inside.