Got It Running - Sort of

[belovedb2]

Well the 4.0L is in the beloved. Wiring completed enough to run the engine, sort of. Idles for a short time. One circuit that I have not hooked up yet is the wires for the throttle sensor/O2 sensor. I am a little confused. The 4.0L runs the circuit thru both the clutch pedal position switch and the clutch tripple function switch. (I am assuming that this is to cut the engine to idle if the clutch is pushed or the trans is put in neutral)

On my B2 it does not connect to these switches. I dont even think I have a clutch pedal position switch or the the clutch tripple function switch that would be used for the throttle sensor/02 sensor. Any thought as to how to wire this part of the circuit?

 

[adsm08]

What year is your donor?

 

[belovedb2]

Doner was a 93 Explorer. B2 is a 86. I have the electrical manuals that show the difference in the wiring. Wondering if anyone else came across this issue.

 

[holyford86]

How are you wiring it? When I wired my ranger for the 4.0 I made the explorer EEC/engine harness work with the 86 dash wiring. I ask because i did the same swap (year wise) and I didn't have to mess with the o2 sensor wiring, or the TPS wiring. What is the wire color(s) that you are having trouble with?

 

[belovedb2]

I am using the 4.0L harness on the engine which includes the connectors to the O2 sensors and the Throttle sensor. To feed these components the 4.oL engine uses a Gray with a red strip wire that comes from the PCM from pin 30 thru both the clutch pedal position switch and also (in parralel) thru the clutch triple function switch. Then the GY/R wire is wired to the O2 and throttle sensor and back to the PCM using pin 26 for the throttle sensor and pins 29 and 46 for the O2 sensor. I also noticed that this circuit goes directly back to the PCM on pins 46 and 49.

My thinking is that the engine should idle without this wire since the cultch switches would be open and the circuit not in play. Of course without the throttle sensor you could not accelerate.

On the B2 the clutch pedal are not wired into this circuit. The throttle sensor is tied to ground on one side, the PCM and ignition switch. Same for the O2 sensor.

On the B2 I did find a clutch switch that is used for the speed control. Used to disengage the power if you press the clutch.

 

[holyford86]

The grey/red wire is a signal return wire, It serves the same function as the black/white wire on your 86. You could not use the CPP switch and all you would get is a code for it. On an 86 the CPP switch is a separate switch than the clutch interlock switch. Even though the later triple function switch will fit onto the master cylinder rod you will not be able to push the clutch down because the pedal arm will hit the switch (ask me how I know)...

 

[belovedb2]

Thanks. I knew someone had tackled this issue. I plan to wire up the 4.0L without the use on the clutch switches, since the B2 does not have these switches for this purpose. I will bridge the output of the PCM, wire LB/Y with the wire to the throttle sensor, GY/R. This should do it.
I replaced the clutch master cylinder and noticed the new switch attached to the rod. I could not get it through the dash hole and saw that it would be difficult re-installing it, so I just removed it. Good thing Thanks again.

 

[holyford86]

I just left mine unhooked, it didn't do anything driveability wise, it just throws a code for CPP switch fault

 

[belovedb2]

I am surprised, but it is running. I wired it as I stated and the throttle works ok. It's running a touch rough. The engine has been sitting around for a year as I worked on this project. I cleaned the injectors and have fresh fuel. Thinking of getting a dianostic tool to read the codes. May help in determing the cause of the rough condition.

 

[adsm08]

Even though the later triple function switch will fit onto the master cylinder rod you will not be able to push the clutch down because the pedal arm will hit the switch (ask me how I know)...

Unless you swap the pedal arm out of an 88. That makes it work.

Ask me how I know.