Hootis

As fixing some vacuum lines today. Notice these two plugs not plugged in.

Everything works fine. Just curious.

MonacaYankee

What year is your cherokee?

Hootis

Sorry. 1988 4.0 5spd no cruise.

The single is back by between the back of the motor and the coolant bottle.

The 4 prong is on the throttle body.

MonacaYankee

I don't know a lot about the Renix Cherokees. I don't think I have either of the connectors that you do.

I think Cruiser54 can help you.

cruiser54

First photo shows underhood light plug.
Second photo shows the TPS plug for automatic trans equipped vehicles.

You need to visit here and do Tips 1 through 5.
www.cruiser54.com

BooGTS

Why would he need to do 1-5 if everything works and the plugs aren't needed that he had the question about?

cruiser54

The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, failed emission tests, and wasted money replacing components unnecessarily.

All the components listed below ground at the dipstick tube stud:

Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition Control Module, Fuel Injectors, ECU main ground (which other engine sensors ground through, including the Oxygen sensor, Knock Sensor, Cruise Control and Transmission Sync signal. All extremely important stuff.

The factory was aware of the issues with this ground point and addressed it by suggesting the following: