Request - Video of REM readout at idle for a healthy 4.0

[PhilisDiller]

Hey all,

 

The MJ I picked up was the first Jeep i've ever driven (besides renting a new wrangler) and I don't have a good point of reference for what a health Renix 4.0 should drive like. I'm hoping to actually go test drive one in my area, however they are far and few between and the closest ones for sale are about 1.5 hours away. Too busy for that right now. 

 

I'm hoping someone with a healthy running Renix 4.0 that owns the REM unit can show me a video of what outputs they are getting at idle.

 

Readings I'm extremely interested in

O2 output reading and swing rate at idle -I'm trying to get a better gauge for what the O2 swing should look like - I feel like mine is a slow swing and it takes on average roughly 2 seconds to complete one full Low -> High -> Low cycle. I've heard it's supposed to swing "lightning fast". I've been trying to source a Mopar 53004245 O2 sensor but those are nearly impossible to find. The O2 sensor I have now is a NTK 23553 but it's the newer 4 wire sensor.

 

Vacuum - On NickInTimes website, he says healthy vacuum should be above 15Hg. Mine floats between 16 and 17Hg, but I've heard it should be closer to 18+

 

ST In Close Loop - Would like to see what range a health 4.0 ST should be at. I know in theory, it should be 128, but just want to see real world feedback. Also, bonus points if someone has 746 injectors installed. I've heard ST drops to around 70 with those injectors. However I'm bouncing between 0-20ST at idle. When cruising most of the time I'm able to maintain around 40-60ish, but idle is a bit concerning for me.

 

Pulse width/Duty Cycle at Idle in OL and CL - Going from OL to CL, my jeep leans out the the fuel by around 30% down. In OL pulse width is 6.9mS, but when it's able to hold CL, I have around 5ms pulse width at idle. I do have the 746 injectors. I just want to see what a normal Renix jeep pulse width is.

 

In advance, I really appreciate it!

[fiatslug87]

What display rate is your REM set to? I think there are four settings: Slow, Medium, Fast, and Ludicrous.

[PhilisDiller]

27 minutes ago, fiatslug87 said:

What display rate is your REM set to? I think there are four settings: Slow, Medium, Fast, and Ludicrous.

I have it set to ludicrous. I was able to find a video of a jeep that was "running rough" and his O2 was swinging about 5x faster than mine at least

[PhilisDiller]

For some context, my jeep seems to be running a bit rich still.

I've gone through and done all of Cruiser54s tips 1-6, except the Coil/ICM fix. I have no issues with starting her and she ALWAYS starts after 1 sec of cranking, not 4-6 seconds like I've seen reported from other Renix owners.

 

Here's everything that I've done since I got her.

Eliminate C101 connection - verified ground sensor resistance below 0.5 Ohm for all sensors

New FPR - verified fuel pressure at rail 31/39PSI

Rebuilt 746 injectors

New exhaust to fix bad exhaust leak

New O2 sensor(NTK23553)

Adjusted TPS to 16% (unable to get 17%)

New IAC

Verified MAP sensor is reading correct and not leaking against a vacuum gauge

Blocked off my EGR because my EGR was faulty

New spark plugs NGK ZFR5N

New wires

Indexed the Dizzy and new cap n rotor

new 195f thermostat because my running temps were low

New IAT sensor because the one that was in there was wrong resistance range reading 60f colder

Cleaned Throttle Body

 

Everything I've done has helped a little bit but never as much as I'd expected. For example, when my FPR was bust and I was getting 40PSI at the rail, I was convinced I had found the source of my running rich issue. Injectors are the thing that FINALLY allowed it to maintain Closed Loop at idle, but even then it's at the limits of the ECU.

 

The only thing I can think of that could still be causing issues would be the ECU or possibly bad O2 sensor. Although it does swing, it's slow. When running in OL, my O2 sensor reading is basically STUCK floating around 0.5-0.6V. I know it reads lean conditions just fine because when decelerating above 2500RPM I know fuel is cut and the O2 is reading 4.8V or something. It's only after it has trimmed 30% of the fuel that the O2 sensor even begins to start registering readings that aren't just "Rich". That leads me to believe it's just running stupid rich. 

[JMO413]

https://youtu.be/Df0aXYveFuk

 

This was when it was really cold here is beautiful Iowa. 0 ish outside temp.

[PhilisDiller]

 

44 minutes ago, JMO413 said:

https://youtu.be/Df0aXYveFuk

 

This was when it was really cold here is beautiful Iowa. 0 ish outside temp.

Wow great video.
what injectors are you running? 
 

here's the things I noticed right off the bat. 
- your O2 sensor is muuch faster mine and tighter range than mine. 
- your gph usage is lower than mine, even though my pulse width is shorter than yours. I’m assuming that’s because my rpm is higher 1000 vs 800 

- your duty cycle is lower than mine even though the pulse width is higher. 

you - 6ms 3.1% duty cycle

Me - 5.1ms 4.2% duty cycle.

Jeeze, as soon as I type this out I realize it’s also due to my higher RPMs.

 

here's a video after shes been warmed up for comparison! This was right after I installed my injectors and my idle increased from 750 to 1050 from the install  

 

[JMO413]

I'm running 746 injectors.

[PhilisDiller]

@JMO413 Do you remember what band Oxygen Sensor you are running? 

 

Ahhh reading through your build thread I see you have a NOS O2 sensor. Lucky bastard!

[JMO413]

24 minutes ago, PhilisDiller said:

@JMO413 Do you remember what band Oxygen Sensor you are running? 

 

Ahhh reading through your build thread I see you have a NOS O2 sensor. Lucky bastard!

It took allot of looking to find that sensor! It wasn't luck it was perseverance and continual looking.

[PhilisDiller]

8 minutes ago, JMO413 said:

It took allot of looking to find that sensor! It wasn't luck it was perseverance and continual looking.

Hehe, I’m on the hunt now!
I’m thinking of swapping my old o2 sensor in to see if it was never bad in the first place. Damn these rare renix era jeeps. Every parts car in my area is 90+ and all junkyards within 3 hours haven’t had a renix Jeep come through in the last 4 months. 

[PhilisDiller]

2 hours ago, JMO413 said:

It took allot of looking to find that sensor! It wasn't luck it was perseverance and continual looking.

 Thanks a million for listing the NOS O2 part number in your build thread. I used the parts catalog to get the O2 number - 53004245, but can only find crappy Crown ones. I hadn't seen the part number 4713639 used anywhere. Even searching Comanche club for "4713639" your build thread is the ONLY post that has that number.

 

I got SUPER lucky and found some on ebay. I picked up two so I don't have to worry in the future when it's even more difficult to find. They'll be here next week!

There's one more available on ebay. I paid an arm and a leg at $92 each though

[JMO413]

You're welcome. Good to hear your found a couple. I always try to list the part numbers I use/ find so others don't have to search like I did/do. I've been a parts guy for 20+ years so it's just what I do.

[PhilisDiller]

You're a good man