Renix Engine Monitor

Review of the Nick In Time Renix Engine Monitor

My Off Road Jeep is an 88 two door with the Renix engine controller.  It has also been stroked and bored to 4.7 liters.

Based on the engine builder (Titan Engines) recommendation, I installed Ford injectors.  However, the engine has always run rich at off-road speeds.

Since the scan tool to read the Renix version was discontinued long ago and the supply has dried up on Ebay, I have not had a way to read the codes or do much trouble shooting on my Renix engine.

I was excited to read some time ago that people were working on a way to use an Arduino to read the data stream. However, I never had the patience to learn to build one or even try to translate the instructions from Russian.

But then I found Nick In Time Designs. He has built a nice unit that not only reads the data but interprets it in a easy to read format.  He has recently sold a few of the hand made units and I was lucky enough to snag one.

I hooked it up in my old Jeep this weekend.  I had a little trouble getting the 3D printed adapter to fit on the connector under the hood but it was just a very snug fit.  I then set the switch to 4.0 and closed the cover. I then plugged in the supplied Ethernet cable. I found a plug in the firewall and routed the cable inside.

I ended up mounting the module in the hole where the radio used to be with now also has my winch controls. I then plugged in the other end of cable to the 3D printed display module.

I am amazed at the amount of data that the device reads out.  I made a few loops around the trail on my farm.  I did have difficulty driving the narrow trails and watching the changing numbers at the same time 😉

I did learn what I suspected, but it wasn’t as bad as I thought.  The engine does run rich most of the time and will not stay in closed loop control mode because of it.   It does occasionally go into closed loop and I can watch the O2 reading switch from lean to rich so the O2 sensor is working properly.

My next step will be to swap to some smaller injectors like I did on my Dad’s Wagoneer. Then I can enjoy watching the data stream again.


I hooked up the monitor to Dad ‘s Wagoneer to see what the difference in O2 reading would be.  I was a bit surprised to find the yellow trouble light on on the module.  Cycling through the data showed me a low TPS reading.

I tested and it appears the sensor is bad. This is likely what causes his off idle stumble.  I will see what happens when the new sensor arrives.