Thanks for all the help so far, guys. This thing has me stumped. I have no problem with building engines, carburetors or NORMAL fuel injection, I've got mid/late 80's MOPAR 2.2/2.5 TBI and Turbo down pat, heck, I work at a blasted KIA dealership and have no problems with the new cars... But this thing has me, plus 5 other guys at our shop scratching our heads (including an old Dodge mechanic!)

 

Ok, went ahead and just replaced the MAP sensor, started it up, and TRIED to take it for a drive around my works parking lot... No change at all.

 

I at least got a little good news after my last post- still no luck on the fitting for our fuel pressure gauge, BUT my service manager has acquired a brand new JEEP-1 connector for the shops MODIS, so now I can plug in and see wtf is going on!

 

Fuel Pressure? My return was clogged. I had fuel so I checked everything else long story short it ran like it was on choke. checked fuel pressure fixed problem

 

Get in the "state display" mode. At least that's what it's called in the DRB. Watch CTS, O2 sensor, and IAT while wiggling the engine wiring harnesses.

 

Ok, this is the entire list I got off the MODIS "live data" stream. This was off a cold start, and it only ran long enough for me to get this info, then I shut it off:

RPM- 600
O2 v- 4.98
Inj (ms)- 7.0
Loop- Open
Exhaust- Lean
ST Fuel Trim- 128
LT Fuel Trim- 132
MAP SNSR (v)- 2.3
MAP (kPA)- 51
Baro Pres (kPA)- 101
TPS (v)- .39
Throttle (%)- 8
Throttle SW- closed
Fuel Sync- "+"
Coolant (C)- 69
Charge Temp (C?)- 38
Knock- 0
A/C Switch- Off
A/C Request- No
EGR- Off
Battery Volts- 14.0
PROM B01078FE


What jumps out at me are the O2 voltage, lean exhaust, Inj. (ms), and fuel trims. I tested the O2 sensor (the only test I could find for it at the time was for the heater circuit)- "resistance reading across terminals A and B on the connector should be between 5-7 Ohm, if it read infinite, replace the O2 sensor". Mine read infinite. The O2 voltage reading NEVER changed the whole time I had it running. As for the injectors, granted I'm used to seeing new cars with pulse widths of around 1.6 ms, but a solid 7?!

 

O2 should be switching fairly rapidly from near 0 to near 5.0.

Should be in CLOSED Loop.

Throttle should be 13% to 17% and CLOSED.

 

So, am I correct in thinking the O2 sensor is causing this, being as it's "locked" at 4.98v? Would that also cause the "open loop" status (and low throttle %, or is that a stop screw adjustment?).

I love my Jeep, but I have come to the conclusion that I REALLY don't like RENIX... LOL

 

Yep, yep, TPS out of adjustment, and I love Renix.

 

Cool, I have an O2 sensor being delivered to my work tomorrow. As for the TPS, what is the REAL way to adjust that thing? Is it the input voltage X .83 on the square plug method? *See earlier post*

 

Off topic a bit but how do you get the tps off without breaking the torx heads.

 

Try these. Written up by a guy with a questionable background at best, but generally recognized as the best way to adjust the TPS. Use the "engine" side, flat connector per the instructions.


RENIX TPS ADJUSTMENT
Before attempting to adjust your TPS 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.
IMPORTANT NOTE: Using the positive (red) lead of your ohmmeter, 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.
MANUAL TRANSMISSION: RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body. This manual transmission vehicle TPS provides data input to the ECU. The manual transmission TPS has three wires in the connector and they're clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. 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. Adjust the TPS until you
have achieved this percentage. If you can't achieve the correct output voltage replace the TPS and start over.
AUTOMATIC TRANSMISSION: RENIX automatic transmission equipped XJs has 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 the manual transmission equipped vehicles—
FOR 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. Key ON, measure voltage between "A" positive and "D" ground. 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.
If you have TRANSMISSION issues check the four-wire connector side of the TPS.
If you have ENGINE issues check the three-wire connector side of the TPS. 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.
Revised 04-08-2012

 

Spray the bolts with a penetrating oil first. Turn them clockwise ever so slightly before removing them in a counter clockwise motion.

 

Shouldnt the Renix be in open loop when it's still not at operating temperature (off a cold start)?? Also thats a real neat scan setup youve got there! Best of luck to you.

 

It should be in "closed loop" on a cold start. It will get it's info for running from pre-programmed settings. Once it heats up to operating temp, it switches to "open loop" and actively adjusts settings based on info from all the sensors.