Jump to content

Injector Harness Question


RDAN1
 Share

Recommended Posts

I pulled the injector harness from my 88 4.0 today to clean it up and also to clean out connector 101 (wow!). At the end of the harness, wrapped in foil is a bare wire as per the picture. It doesn't connect to anything as far as I can tell. Should I just tape it in place against the foil wrapping and move on or?

 

 

 

Link to comment
Share on other sites

Boy, I wish I still had my parts Jeep around as I'd open up the harness. IIRC, the only sensor that used a shielded type wire was the O2 sensor. While you're in there check the crimps on the sensor ground wires. Should be a clump of three in the harness heading towards the C101, goes to one wire into the C101. Going out of the C101 that wires goes to another clump of three near the MAP. If you can bypass the C101 and tie both clumps of three together and solder it would be better.

 

This might help ya.

 

Find your Intake Air Temp sensor. It's the sensor just to the rear of the throttle body, has 2 wires, and screws into the intake manifold.

Where it's connector plugs into the harness you will see that one of the wires on the harness side is brown with a white stripe. Follow the brown with white strip wire back into the harness. You'll have to open up the split-loom plastic sheathing to follow it. It will come to a splice with 2 other brown with white wires. They're from the TPS and the CTS. The 3 wires will be spliced to a single wire headed toward the C101 connector if you have an 87 or 88. If you have an 89 or 90, you do not have the C101 bulkhead connector.

 

Now go to the MAP sensor. Follow the brown with white wire into the harness from there. You will find a splice with 2 more brown with white wires. At the splice you will find the 3 wires connected to a single brown with white wire going toward the C101, or just along the firewall towards the engine if you have an 89 or 90. Along with the MAP sensor that you traced, they are the ECU sensor ground port and the diagnostic connector on the passenger inner fender.

 

You now have 2 sets of 3 brown with white wires, one near the firewall and one near the engine.

 

Cut the splices out of each set of wires eliminating not only the crappy factory splices, but also the single wire between them. Bring both sets of 3 wires together. Solder the 2 sets of wires together and insulate them properly with tape or shrink tubing.

 

Zip-tie up your new sensor loom to allow for engine movement. I prefer to cover it with some new split-loom or wrap it neatly with electrical tape when done.

 

 

 

Revised 12-02-2011

Link to comment
Share on other sites

Boy, I wish I still had my parts Jeep around as I'd open up the harness. IIRC, the only sensor that used a shielded type wire was the O2 sensor. While you're in there check the crimps on the sensor ground wires. Should be a clump of three in the harness heading towards the C101, goes to one wire into the C101. Going out of the C101 that wires goes to another clump of three near the MAP. If you can bypass the C101 and tie both clumps of three together and solder it would be better.

 

Thanks for the info. The bare wire shown is foil wrapped with the 2 wires going to the knock sensor (yellow with black stripe & purple ? with white stripe). When I pulled off the old loom, the bare wire was just open on the end like it's shown in the photo. I can trace all three wires back in the harness but they don't appear to go to the 101 connector. I'll double check that tomorrow but it looks like they go into connector 116 ???

Link to comment
Share on other sites

Find your CPS connector and follow the harness from the connector upstream. If it remains a single harness -- all by itself -- directly to the firewall, most likely your truck was upgraded. There was a TSB a number of years ago about the CPS harness being too long and the signal degrading between the sensor and the ECU (which is under the dashboard in the Renix trucks. The fix was a replacement harness that went straight from the CPS connector through the firewall into the ECU.

Link to comment
Share on other sites

Find your CPS connector and follow the harness from the connector upstream. If it remains a single harness -- all by itself -- directly to the firewall, most likely your truck was upgraded. There was a TSB a number of years ago about the CPS harness being too long and the signal degrading between the sensor and the ECU (which is under the dashboard in the Renix trucks. The fix was a replacement harness that went straight from the CPS connector through the firewall into the ECU.

 

 

OK I traced it back from the cps and the white with black stripe goes to 101 and the purple with white stripe goes to 116. ?

 

I also found the splices cruiser54 mentioned and can deal with those splices before I reassemble .

 

So back to the original question : Can I just tape the bare wire back against the foil tape and move on? also since I have a manual, can I terminate and seal the wires going to the tps auto trans connector 259?..doing away with that connector would clean up the harness some..??

Link to comment
Share on other sites

The knock sensor has foil shielding to prevent spurious signals from reaching the computer. If your truck doesn't have a knock sensor, maybe the factory was using up supplies of prior year harnesses when it was built. If the foil does in fact go to the knock sensor, you can just ground it as a "shield drain" and not worry about it.

Link to comment
Share on other sites

The knock sensor has foil shielding to prevent spurious signals from reaching the computer. If your truck doesn't have a knock sensor, maybe the factory was using up supplies of prior year harnesses when it was built. If the foil does in fact go to the knock sensor, you can just ground it as a "shield drain" and not worry about it.

 

I do have a knock sensor so I just taped the loose bare wire back against the foil insulation. While I had it open, I also cut out/removed and sealed up the ends of the 3 wires going to the transmission tps plug since I have a manual and it's not used/needed.

 

Thanks to everyone for their input.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...