3.4 swap into 1985 Jeep Cherokee questions?

[Canyonero]

Couldn't say for sure, I say it's time to get the tester out again. Find out where those wires end up...

[bszopi]

What wires do you have left unconnected? Looking through you list a couple pages back, there were several grounds and at least 1 ECM power (pink) that you listed as not being connected. ALL ECM power wires and ground wires need to be connected to ensure everything is getting power from where it needs it.

[cardana24]

What wires do you have left unconnected? Looking through you list a couple pages back, there were several grounds and at least 1 ECM power (pink) that you listed as not being connected. ALL ECM power wires and ground wires need to be connected to ensure everything is getting power from where it needs it.

All wires marked ECM ground on the pin out are all grounded to the fire wall. I think all of my pink wires are hooked up too but I am not with my jeep now, I'll post back in a few hours when I am at the jeep.

Should all pink wires be hooked to switchable power?

[cardana24]

I spent several hours on the jeep last night with the multi meter. I did not connect any more wires but rather tried to figure out what the wires are that I had left. I put all of my information in a spread sheet if any one would like it emailed to them. I have listed all of the wire in each harness and they are in the order you would see them on the harness.
10 pin white harness Nothing in this harness is hooked up
Tan- B19 Serial Data
Green/White- B28 Buffered Speed Output
Dk Blue- B18 2nd gear start mode indicator lamp control
Green/White- nothing on ecm
Green- about 10 different pins
Red- lots of pins
Tan- lots of pins
Brown- lots of pins

4 pin Black harness
Grey- Nothing (Caynonaro said it was 5V ref) Nothing
Orange- B14,B15 Battery (keep alive memory) They join as one wire and are hooked to constant 12V
Black/White- PCM ground Grounded
Purple- Ring terminal in harness Nothing

10 Pin Blue Harness
Lt Blue- C10 2nd start mode switch signal (not hooked to anything but when the ignition is switched on it gets 12V)Brown/White- B7 SES indicator control Nothing
White- Nothing (Caynonaro said its for the tachometer) Nothing yet, I'm waiting for my MSD adaptor thing
Dk Blue- Nothing Nothing
Green/White- A2 A/C request Nothing
Pink- C3 Ignition Feed Hooked to the ignition line from the jeep
Lt Blue/Black- A18 Brake signal Nothing

10 Pin Grey/Black
Pink- C12,C14,C16 Injector Drivers Cyl's 3,1,5 Ign. Wire on the Jeep
Green/White- B6 A/C compressor clutch Relay control Nothing
Green- C2 A/C Clutch status Nothing
Brown- B3 Secondary air injection system air bypass solenoid Nothing
Brown/tape-B11,B12,B13 EGR# 1,2,3 control NothingPink/tape- B20,B32,A6,C17,C20,C21,C25,C31,C1 Grounded
Green- Same as Pink/tape Grounded
Pink- C32, C15,C13 Injector driver Cyl's 4,6,2 Ign. wire on the jeep

3 Pin Black
Grey- A31,A30,A17,A1 Various sensor grounds Grounded
Dk Blue- A3 A/C evaporator temp signal Nothing
Black- A1,A17,A31 Various sensor grounds Grounded


Sooooooooo....what do I need to hook up out of all of this stuff. Do I need to hook all of those grounds to something? What about the Injector Driver Cylinder stuff...what's that? Anyone what to help?

Here is how I currently have the wires hooked up that are not not direct plug and play wires (sensors) How should they be hooked up. With this set up I am not getting power at the ICM pink wire, nor am I getting power on the power lead on the cam shaft position sensor. When I route an ignition wire to these wires the wire gets hot quickly and starts to smoke. I also checked the ground on the 450 black wire at the ICM and it has a good ground right by the water neck.

Also the locations of these wires are just what I found by checking continuity from the wire in question to the plugs on the ecm...feel free to double check me, I don't know where the wires with lots of pin locations are supposed to go. Is there a wiring diagram showing where these plugs are and where the wires go that are associated with each plug?

Why am I getting switched 12 V from pin C10 (second start mode switch signal) I don't even know what that is supposed to do. I would appreciate any help. I am going to go read through the trouble shooting steps now.

[cardana24]

So I tried running a wire from the light blue wire that I was getting switched 12V on to the pink wire on the ICU. When I switch the ignition on with out the jumper wire hooked up I get 12V at the end of it. When I hook the jumper wire from the light blue wire to the pink wire I no longer have 12V...I have nothing, but as soon as I un hook the jumper I get 12V again...so what is going on? It seems as if something is wrong with the ICM circut but I am not sure how to fix that.

Also something that I did not mention before is that the tan wire on the 10 pin white plug harness gets 3V when the ignition is switched on but I do not have it hooked up to anything. It's one of the ones that I found continuity through a bunch of different pins.

[bszopi]

You want to know my honest opinion? Probably not, but here goes...

I would rip out the harness and start fresh. I honestly can't tell what you have connected were between all the posts. Now granted, I haven't be paying attention to everything (I do read all threads on the forum, but some I just don't try to follow closely), but its starting to look like you may have fried something when you just started hooking everything up to the IGN source, instead of letting things be powered via the ECM.

Oh, and a note on grounding for sensors. I know it sounds wierd, but you can't really just tie them all together. I found this out the hard way. Sensors that are powered from the same 5v reference source need to be grounded together, and separate from other grounds. I'm not saying you can't ground them all to the same spot on the engine/chassis. I'm just saying you shouldn't tie all the wires together. This will affect some sensors ability to register the correct values.

[cardana24]

You want to know my honest opinion? Probably not, but here goes...

I would rip out the harness and start fresh. I honestly can't tell what you have connected were between all the posts. Now granted, I haven't be paying attention to everything (I do read all threads on the forum, but some I just don't try to follow closely), but its starting to look like you may have fried something when you just started hooking everything up to the IGN source, instead of letting things be powered via the ECM.

Oh, and a note on grounding for sensors. I know it sounds wierd, but you can't really just tie them all together. I found this out the hard way. Sensors that are powered from the same 5v reference source need to be grounded together, and separate from other grounds. I'm not saying you can't ground them all to the same spot on the engine/chassis. I'm just saying you shouldn't tie all the wires together. This will affect some sensors ability to register the correct values.

I see what you are saying but I really don't have that many wires hooked up other than the sensors that are plugged in. Most of the wires that did not go directly to sensors are not hooked up. I have grounded some of them and only a few others have been re routed. If it were up to you how would you hook up the wires I have listed that do not get plugged into sensors? I'm all ears if you know how they should be hooked up.

[bszopi]

Why are they not getting plugged into sensors? I understand the EGR one, but what other sensors do you not have hooked up? Is the crank position sensor hooked up (and with the proper shielded, twisted pair wire)? That right there would cause the engine to not start, although I'm not sure if it would prohibit the injectors from firing. But possibly, as the ECM doesn't know when to fire them since it doesn't know the position of the crank, and therefore the position of the pistons inside the cylinder.

[cardana24]

Why are they not getting plugged into sensors? I understand the EGR one, but what other sensors do you not have hooked up? Is the crank position sensor hooked up (and with the proper shielded, twisted pair wire)? That right there would cause the engine to not start, although I'm not sure if it would prohibit the injectors from firing. But possibly, as the ECM doesn't know when to fire them since it doesn't know the position of the crank, and therefore the position of the pistons inside the cylinder.

Maybe we are not on the same page here. There are several sub harnesses/plugs that do not have any where to plug in...I assume they plug into a module inside of the vehicle...I obviously do not have these modules that they plug into so need to know which ones I need to use in order to get the engine running well. I posted pics of these plugs a few pages back...they are not the plugs that go directly to sensors. Post 160 in this thread has the pictures of the plugs I am talking about.

One thing I was thinking about lastnight is that I do have a lot of grounds run. I am starting to wonder if I set the grounds up wrong. If you look at the pin outs on the ecm plugs there are four wires that are desiginated as ECM grounds. I cut those wires close to the ecm and ran them to the fire wall to be grounded. Then I also have four ground wires in the factory set up that are grounded on the head stud right next to the water inlet neck. Would that cause problems? Am I messing up circuts with too many grounds or grounds in the wrong place?

I'm willing to re do my wiring is someone has a good idea of where my wires need to be run.

[Canyonero]

I agree, I don't know what you might have cooked. When I was working with mine (before I chickened out and bought a custom harness), I first identified all the connectors and cut out everything I didn't need. All the auto tranny wiring, all the AC wiring, cruise control, etc. Though I did leave little tails off the ECU in case I made a mistake and needed to splice something back in. Having everything removed beforehand sure makes things less confusing.

I might put my standalone harness up for sale sometime, after I do my 3400 top end/OBDII swap with a new harness (which I'm doing myself this time). Probably longer than you want to wait though.

Some sensors NEED to ground through the ECM. That's how they read the sensor values.

[cardana24]

I agree, I don't know what you might have cooked. When I was working with mine (before I chickened out and bought a custom harness), I first identified all the connectors and cut out everything I didn't need. All the auto tranny wiring, all the AC wiring, cruise control, etc. Though I did leave little tails off the ECU in case I made a mistake and needed to splice something back in. Having everything removed beforehand sure makes things less confusing.

I might put my standalone harness up for sale sometime, after I do my 3400 top end/OBDII swap with a new harness (which I'm doing myself this time). Probably longer than you want to wait though.

Some sensors NEED to ground through the ECM. That's how they read the sensor values.

I have already cut out the wires from the auto tranny and VSS. I am more than happy to take the wirng out and start over its really just a few wires that are hooked up at this time. If some one could just give me some guidance as to what I need to hook up other than the sensors that are plugged in I would appreciate it. The questions that I have about the wiring all deal with the wires going to the plugs that I have posted about and half of that stuff seems to be for the AC.

Does anyone know where the 4 pins that are marked ECM ground on the plug pin out should be connected? I am willing to try other things but I need more advice other than rip it out and start over.

I am hoping that someone can look at the plugs that I posted and where they are getting continuity back at the ecm plugs and possibly help me figure out where they go. I know I am going down the road less traveled by running my 3.4 fuel injected, but I am hoping there may be a little more info out there to help me finish this soon. Thanks again everyone.

[bszopi]

Where are the wiring diagrams that you are using? You listing the ECM pin locations is useless to me if I'm not looking at the actual ECM wiring diagrams, as pinouts of ECMs different between models and years.

[cardana24]

Where are the wiring diagrams that you are using? You listing the ECM pin locations is useless to me if I'm not looking at the actual ECM wiring diagrams, as pinouts of ECMs different between models and years.

What's your email? I have some files that Caynoaro ( i know I misspell your name every time but I cannot remember how to spell it) Anyone else who would like to help me with this post your email and I can send you the wiring diagrams I am working with and the pin outs for the harness plugs on a 94 Fbody.

[bszopi]

bszopi@60degreev6.com or you can just post them in the photo gallery. Once I get them, if they are good copies, I'll place them on the site for others to use.

[cardana24]

bszopi@60degreev6.com or you can just post them in the photo gallery. Once I get them, if they are good copies, I'll place them on the site for others to use.

sending them now. Let me know what you think.