Category: Performance Improvement

Review of the Nick In Time Renix Engine Monitor REM

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 troubleshooting 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 an easy-to-read format.  He has recently sold a few of the handmade 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 the 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.

Update:

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. Update: the new TPS cleared up the stumble and the odd shifting of the transmission.

My Dad has a renix Wagoneer that he and my son restored.

My son bought this Jeep from his high school history teacher. He and my dad repainted it and Scott restored the interior using parts from Pull a Part and from another donor Wagoneer he found.

Continue reading “Dad’s XJ Wagoneer”

Opening up my new crate engine for my Jeep XJ

I picked up my new engine form R&L carriers today. I figured it would be easier to pick it up at the freight depot than deal with getting a truck backed up to my shop.

I used the lift to unload from the Pick Up.

Continue reading “New 4.0 crate engine unloading and unboxing”

How I replaced the engine in my 1991 Jeep Cherokee.

My old XJ has served me well for nearly 500,000 miles. The odometer stopped working at 444444 and I have swapped clusters a couple of times, so I really don’t know what the current mileage is.

Continue reading “Engine replacement Jeep Cherokee XJ”

Weird trouble with first start of my new engine

When I put in my new engine I expected it to start up right away. I had carefully aligned the distributor, checked all the electrical connections and bled the air out of the fuel system.

But when I hit the key it simply spun over and never fired.

I put a light in one of the spark plug wires and it flashed indicating I had spark. That meant that the Crank Position Sensor was working.

Continue reading “Jeep 4.0 no start troubleshooting puzzle”

Using a Thrush Glass pack to get more clearance

For years I ran a straight pipe on my Jeep. I liked the sound but after hours on the trail the noise would get to me.

So a couple of years ago, I replaced the entire exhaust system with stock style components. The truck has been nice and quite since then.

However, the stock muffler is not very strong. And, it hangs in a place susceptible to damage. After just a few trips off road, mine was crushed

Continue reading “Jeep XJ muffler replacement”

Fitting TJ brake lines to my XJ and freeing stuck bleeder screws.

For years I have been running with the stock brake lines with my three inch lift. I just unbolted and rearranged the metal brake lines to get enough droop.

Occasionally, however, I will snag something and give some undue stress on the brake lines. After one of my wheeling partners broke a brake line on the last trip out, I decided to make an upgrade.

For various reasons, I did not want to go with braided stainless Teflon lines. I wanted to stay with stock DOT-style rubber lines.

I decided to try 91 TJ lines. I figured they used the same Dana 30 axle and the body was further away so the lines should be a little longer. The TJ line has a longer metal line before the rubber hose begins giving it a bit more reach.

I ordered Raybestos part numbers BH38861 and BH38862.

Continue reading “Longer front brake line Jeep XJ”