Progress, my friend. Get teh throttle body set exactly like it should be. CHANGE the fuel filter and reset the TPS once again on the engine side.

Here's my revised TPS adjusting instructions:


RENIX TPS ADJUSTMENT

Before attempting to adjust your TPS, there are two things that need to be done.

1) Be sure the throttle body has been recently cleaned. It's especially important that the edges of the throttle butterfly are free of any carbon build-up.

2) With the Key OFF, and using the positive (red) lead of your ohmmeter, set on the lowest scale, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. I can provide an instruction sheet for that if needed.

TPS ADJUSTMENT FOR ENGINE ISSUES

Both RENIX manual and automatic transmission equipped XJs and MJs have a flat three-wire connector to the TPS which provides data input to the ECU. The three wires in the connector are clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors. Note the voltage reading--this is your REFERENCE voltage. Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you
have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can't achieve the correct output voltage, replace the TPS and start over.

Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage.

TPS ADJUSTMENT FOR AUTOMATIC TRANSMISSION ISSUES

RENIX automatic transmission equipped XJs and MJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as outlined above—FOR ALL ENGINE MANAGEMENT RELATED ISSUES.

However, the automatic TPS also has a square four-wire connector, clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. First off, DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage between "A" positive and "D" ground by back-probing the connector. Note the voltage. This is your REFERENCE voltage. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage. If you can't, replace the TPS and start over. So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU.

For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced. The square 4 wire connector is just not used.
Revised 12-15-2013

 

Tomorrow, I plan to address the dirty fuel problem, new filter and possibly drop the tank, inspect the pump and inside of the tank and send air through the lines.


I'll then re-check my tps and make sure its in spec with the engine off and on.

 

Good plan. That hose inside the tank TO the fuel pump may be shot. The new fuels raise hell with those old hoses.

 

I did not pull the pump, YET. I pulled my plugs and noticed they are showing rich, how rich, I don't know but definitely rich.

Fuel pressure regulator?
Leaking injector?

Any way to test for either of the two?

 

Let's see some pics of the plugs.

In order, causes of an overrich condition on a REnix:

MAP sensor and/or it's vacuum source
CTS
IAT
Oxygen sensor.

 

I will get pics tomorrow.


What I have done so far is:


New thermostat, the jeep didn't have one. It has a factory spec 195* stat. After this install is when I first got the high idle issue. Then that issue led to the rest.


TPS adjustment to spec
IAC Cleaning
Throttle body cleaning
New plugs gapped at .35
New rotor on distributor
Grounds refreshed
C101 Cleaning
New fuel filter


Who/where can plug into this Jeep and read my 02? and temperarture sensor?


I'm running out of patience with this thing. I pulled the fuel pump for inspection and everything looks to be fine.

 

Someone with a Snap-On MT2500 can read the live data from the O2 sensor.

 

Can they check the temp sensor as well?

 

Yep, and the IAT. It all reads "real time". Every sensor.

 

I'll see if I can get my hands on one.


I'm leaning towards CTS considering these issues didn't start until I installed the factory 195* T-Stat.

 

CTS and IAT, along with MAP can be tested with a multimeter....

MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR—PCM INPUT

OPERATION
The MAP sensor is used as an input to the ECU/PCM. It contains a silicon based sensing unit to provide data on the manifold vacuum that draws the air/fuel mixture into the combustion chamber. The PCM requires this information to determine injector pulse width and spark advance. When manifold absolute pressure (MAP) equals Barometric pressure, the pulse width will be at maximum. A 5 volt reference is supplied from the PCM and returns a voltage signal to the PCM/ECU that reflects manifold pressure. The zero pressure reading is 0.5V and full scale is 4.5V. For a pressure swing of 0–15 psi, the voltage changes 4.0V. To operate the sensor, it is supplied a regulated 4.8 to 5.1 volts. Ground is provided through the low-noise, sensor return circuit at the PCM/ECU.

The MAP sensor input is the number one contributor to fuel injector pulse width. The most important function of the MAP sensor is to determine barometric pressure. The PCM/ECU needs to know if the vehicle is at sea level or at a higher altitude, because the air density changes with altitude. It will also help to correct for varying barometric pressure. Barometric pressure and altitude have a direct inverse correlation; as altitude goes up, barometric goes down. At key-on, the PCM/ECU powers up and looks at MAP voltage, and based upon the voltage it sees, it knows the current barometric pressure (relative to altitude). Once the engine starts the PCM/ECU looks at the voltage again, continuously every 12 milliseconds and compares the current voltage to what it was at key-on. The difference between current voltage and what it was at key-on, is manifold vacuum.

During key-on (engine not running) the sensor reads (updates) barometric pressure. A normal range can be obtained by monitoring a known good sensor. As the altitude increases, the air becomes thinner (less oxygen). If a vehicle is started and driven to a very different altitude than where it was at key-on, the barometric pressure needs to be updated. Any time the PCM/ECU sees Wide Open Throttle (WOT), based upon Throttle Position Sensor (TPS) angle and RPM, it will update barometric pressure in the MAP memory cell. With periodic updates, the PCM/ECU can make its calculations more effectively.

The PCM/ECU uses the MAP sensor input to aid in calculating the following:
Manifold pressure
Barometric pressure
Engine load
Injector pulse-width
Spark-advance programs
Shift-point strategies (certain automatic transmissions only)
Idle speed
Decel fuel shutoff

The MAP sensor signal is provided from a single piezoresistive element located in the center of a diaphragm. The element and diaphragm are both made of silicone. As manifold pressure changes, the diaphragm moves causing the element to deflect, which stresses the silicone. When silicone is exposed to stress, its resistance changes. As manifold vacuum increases, the MAP sensor input voltage decreases proportionally. The sensor also contains electronics that condition the signal and provide temperature compensation.

The PCM/ECU recognizes a decrease in manifold pressure by monitoring a decrease in voltage from the reading stored in the barometric pressure memory cell. The MAP sensor is a linear sensor; meaning as pressure changes, voltage changes proportionately. The range of voltage output from the sensor is usually between 4.6 volts at sea level to as low as 0.3 volts at 26 in. of Hg. Barometric pressure is the pressure exerted by the atmosphere upon an object. At sea level on a standard day, no storm, barometric pressure is approximately 29.92 in Hg. For every 100 feet of altitude, barometric pressure drops 10 in. Hg. If a storm goes through it can change barometric pressure from what should be present for that altitude. You should know what the average pressure and corresponding barometric pressure is for your area.

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR TEST
To test the MAP sensor only, refer to the following:

(1) Inspect rubber L-shaped fitting from MAP sensor to throttle body. Repair as necessary.

CAUTION: When testing the MAP sensor, be sure that the harness wires are not damaged by the test meter probes.

(2) Test MAP sensor output voltage at MAP sensor connector between terminals 1 and 2. With ignition switch ON and engine OFF, output voltage should be 4 to 5 volts. The voltage should drop to 1.5 to 2.1 volts with a hot, neutral idle speed condition.

(3) Test MAP sensor supply voltage at sensor connector between terminals 1 and 3 with ignition ON. The voltage should be approximately 5 volts (+/- 0.5V).

Terminal 1: Sensor Ground (Brown wire/Yellow tracer)

Terminal 2: MAP Sensor Signal to PCM (Dark Green wire/Red tracer)

Terminal 3: 5V Supply from PCM (Orange wire)

 

Today, I bought an CTS and looked up on all data the location. It showed the driver side of the block above the motor mount in the water jacket. In my jeep they had a sensor with a wire running to a mechanical gauge.. I removed that sensor and installed my new CTS and so far it seems good.

I'm letting it sit for a few minutes and going to see if it starts on its own like it should.

 

That could explain alot!! Was the CTS connector just dangling there?

 

Yes the CTS connector was just dangling and filled with mud. The jeep seems to fire right up now. Sometimes it still idles rough but usually cleans up. I just left the shop and came home, I've got to run a few errands then I'm going back up there to see if it starts as easily as it was. I'm also going to clean the IAT sensor and the grounds on the back of the head as well as see if I can wire my mechanical gauge into the right sending unit on the back of the head.

 

Very encouraging! You had mentioned something about dirty fuel a couple of days ago. Have you had time to address that?