CTS connector missing???

OK first a little background...

bought this jeep a couple weeks ago, 87 cherokee laredo 230k miles, 4.0 automatic. The guy said it had developed an intermittent stall/restarting problem. Sure enough, she'll run like brand new money most times, but on occasion it'll just totally die then won't restart. Walk away, come back an hour or day later, starts like nobody's business.

Long story short, I've found the coolant temp sensor is unplugged and the plug nowhere in sight. To be more clear, this is the sensor in the side of the block sending coolant temp to the computer. What I do have is 2 wires sticking out the protective jacket of a harness in pretty close proximity but just sticking out, no connector. Is there anyway to find out what color wires and how many hook into that sensor? Looks like maybe it got chewed up into the axle or something, dunno just guessing.

Any help at all would be most appreciated. Pretty sure I'm well on the way to solving this problem if I can get that little jewel hooked back up.

There are two wires on the CT sensor...
The wires in the harness also contain the O2 sensor and the Knock sensor.
Both have different connections.

If you visit the junkyard, you may be able to obtain the factory plug, otherwise it may be possible to obtain a weathertite connector and solder and shrink wrap the wires on each side... would seem like a better choice to me to get a connector from the junkyard and keep the connector on the sensor and have one solder joint..

as far as the wire color... it MAY not matter..... but one will be 5 volts and the other to ground... the sensor is just a resistor that changes with temperature, and I don't think polarity will matter.

a pdf copy of 88 service manual state the ecu connector for the cts is terminals D3 and C10 to test the wiring harness...

good luck... because I had a similar problem and mine was connected... and checked good...


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Thanks for the reply. Off to the junkyard today I guess. Just as well, I need to find a socket for my front signal light anyway.

Looking at the connector on the sensor looks a lot like the injector connection. Wonder if I could find some generic deal at advance auto would work? (have to pass an advance auto parts on the way to junkyard) would be much faster and cleaner

My Knock sensor had the connector resembling an injector, but the CTS had a weathertite two terminal connector... the same as the Manifold Air Temp sensor just behind the throttle body..........

You need to fix that connector, it will not fix your problem though, a new CPS will however.

have you tried pushing the accelerator to the floor when it won't fire?

My 91 recent'y started flooding once in a great while on startup. If I push it to the floor it will fire right up.

If I hold the gas to the floor I get a momentary sign of life but it won't stay running, dies soon as I release the key. While in a no start condition, engine still hot I have around 275 ohms at the cps, telling me it's doing what it's supposed to. In reading over what the coolant temp sensor does, sending engine temps to the ecu to adjust air/fuel mix, sounds like it's right in the neighborhood of my problem. On a warm start, I can smell gas just like she's flooded. Come back an hour or so later and she fires right up like nobody's business.

I have a trash can full of CPS's the read 275 ohms that don't work some of the time. The ohms test don't really tell much.

I have a brand new in the box gp sorensen cps ready just in case. I was under the impression a cps malfunction would give me no spark or fuel? of which I have both in abundance.

UncleBud said:

I have a brand new in the box gp sorensen cps ready just in case. I was under the impression a cps malfunction would give me no spark or fuel? of which I have both in abundance.

Click to expand...

In that case your correct then but you could have more than one problem.
If it just suddenly quits it could still be the CPS, but the reason it don't restart could be it's flooding because of the CTS not working.