3.4 swap into 1985 Jeep Cherokee questions?

[ssterlingb]

The ICM runs the ignition coils, so it should be wired between the coils and the PCM

[ssterlingb]

Looking at the diagram, there are three connectors on the ICM and the coils wire directly to it. I think it would have to be located on the engine by the coils.
1st connector is power: two wires as described before.
2nd connector is twisted wire to crankshaft position sensor.
3rd connector is to the PCM.

[cardana24]

Looking at the diagram, there are three connectors on the ICM and the coils wire directly to it. I think it would have to be located on the engine by the coils.
1st connector is power: two wires as described before.
2nd connector is twisted wire to crankshaft position sensor.
3rd connector is to the PCM.

Okay, I cut the pink wire on the camshaft position sensor and tied a wire into that and ran it to the ignition lead coming from the jeep. The engine tried to catch when I did this but I had to stop because that wire started smoking. What would cause that? Bad ground? Where is that black/white wire you are referencing? I see the pink one. The crankshaft position sensor is plugged in already...I'm going to go look for that ground wire.

[cardana24]

I'm not sure where that ground wire is. I suck at reading the wiring schmatics. I see the wires going to the cam position sensor, and I see the pink "T" into the ignition wire on the ecm which I already have hooked to the hot ignition source on the jeep. When i turn the ignition to the on position the wire that I tied into the pink wire going to the cam position sensor is getting hot to the touch quickly and it starts smoking in a few seconds. I felt all of the other wires attached to the ignition wire where it is hooked and all of the other wires are cool to the touch. What would cause this wire to start smoking? I now have a fire estinguisher out in the garage

[ssterlingb]

The 1st connector on the ICM is two wires:
1st wire is just shown as a jumper wire to the Pink 239 wire going from the 10 amp fuse #11 in the 10-Way forward lamp harness connector (Black) to the camshaft position sensor.
2nd wire is #450 BLK/WHT to ground.

[ssterlingb]

Since the wire is tied to a 10 amp fuse, and I can't imagine that the sensor pulls much power, the jumper needs to be at leat a 14 guage wire. But if you find the two wire plug on the ICM, it should give you an idea on wire size to the ignition source.

[Canyonero]

It is VERY possible that all six injectors are clogged. That happened to me. Noid lights are like $8, so it's a cheap test.

[bszopi]

The wire would get hot and start smoking if it was a direct connection to ground.

[bszopi]

Although not for your vehicle or ECM, the main connections should be similar (the ECM pin numbers are probably the difference).



Maybe that will help.

[cardana24]

The 1st connector on the ICM is two wires:
1st wire is just shown as a jumper wire to the Pink 239 wire going from the 10 amp fuse #11 in the 10-Way forward lamp harness connector (Black) to the camshaft position sensor.
2nd wire is #450 BLK/WHT to ground.

Okay, is the ICM the thing that the coils plug into? There is a plug on the top end of the thing that the coils plug into that has a two pin plug. One wire is pink and the other is black. Is that the connector you are talking about? Also on my wiring diagram it is showing that wire #450 is black, not black/white. If that is the correct connection I am guessing I should spliced into those two wires, run one to the ignition source and the other to ground?

I'll be trying this again this evening so you guys can keep throwing out suggestions all day.

[Canyonero]

The wiring for the ICM should have been intact in the original harness. You don't need to keep splicing power to various wires in a guess-and-check fashion. You're just going to start a fire.

The ECU needs constant 12v and switched 12v.
Each injector bank needs 12v.
Everything else that needs power will get it from the ECU (ICM, sensors, etc). If they aren't getting 12v from the ECU, then something is wrong and it won't run anyway.

[bszopi]

As shown in the diagram above, the ICM also recieves power from the IGN.

[Canyonero]

Hmmm, indeed it does. I stand corrected.
I'm pretty sure mine is wired different though.
Here is the f-body diagram, which does show the ICM and the Cam sensor on a fuse:

[cardana24]

The wiring for the ICM should have been intact in the original harness. You don't need to keep splicing power to various wires in a guess-and-check fashion. You're just going to start a fire.

The ECU needs constant 12v and switched 12v.
Each injector bank needs 12v.
Everything else that needs power will get it from the ECU (ICM, sensors, etc). If they aren't getting 12v from the ECU, then something is wrong and it won't run anyway.

I am giving the ECM constant power through the orange wire...I forget the pin location. I am giving it switched 12v on the pink wire (it's pin 3 something). So I should not need to run any more wires? I will check to see if the two pin plug at the coil block is getting power.

Can someone please varify that I am using the right pin to to get ignition power?

[cardana24]

As shown in the diagram above, the ICM also recieves power from the IGN.

So you are saying that I do need to splice into the ICM wires (pink and black) and run switched 12v to the pink wire and ground the black wire? Or is the black wire already grounded?