Next Phase - Road Trip Home

[jamespwsullivan]

I have been a member of this forum for quite a few years but have only posted occasionally.  I have learned a lot about my MJ here and try to post only if I actually have something to contribute.  I don't have anything against humor or good natured pokes, but if I don't actually know you I try to be a little respectful. (Of course, that could mean that I have no respect for my actual friends…)

 

One thing that seems to interest a few of us Comanche and early XJ owners is how long a trip you can make in your truck.  I drove mine from south Florida to Indianapolis about 4 years ago.  The truck was overheating pretty severely but with enough stops we made it.  My brother and one of my nephews came along with a support vehicle.  Then it sat in my driveway for a year because I didn't have any place to work on it.  The next step was when my brother offered to let me work on  it in his home shop - in Kirkland, WA - and he and my nephew would help.  I had it transported to Kirkland and that's where we departed from this morning.  Destination - Indianapolis, IN of course.  Somewhere in the neighborhood of 2500 miles.

 

More on the history later but here is a little bit about the truck.  It's a 1987 long bed.  It has had body work done, cab corners replaced; it's been painted the same color as my 1996 XJ R.I.P. (Moss Green Pearl I think?) and the interior converted to gray.  The 4.0 is from a 2003 TJ Unlimited. It had about 70k miles on it when I got it.  The head has been surfaced (since it overheated like crazy!) and the valves done.

 

I'm going to try and post here every day until we get to Indianapolis

 

1/3/2025

10:15 PM PDT

The plan was to get up, load my bag, load Kent's bag, put the cab stuff in the cab and then be ready around 8:30.  At 8:30, my nephews were going to come out to the shop so we could all push in the Volvo sedan and put it on the lift after the Comanche was out the door.  After pictures, I backed the truck out and had it idling on the street waiting to go.  Our friend, Kent Compton said, "Did you notice that your hood is not all the way down on the passenger side?"  I said, "No." 

 

[A long time ago (in this Jeep Comanche pickup time) I installed some spring-loaded hood retaining pins.  If you don't know what those are it doesn't matter.  What matters is how they are installed and what can happen if you cut a corner during the installation.]

 

I attempted to shut the hood but it wouldn't stay down on that corner so I opened it up to see that the passenger side hood pin was completely loose.  I didn't remember all of the installation steps so we started in to figure out how to tighten it.  Eventually we got that done (and added a larger washer in a particularly important location) but now it was noon.  So time for lunch.

 

I didn't mention yet that the weather reports were getting a little concerning as we had originally thought we would cut down toward I-80 from Ellensburg, WA and stay in Baker City, OR and then proceed to Salt Lake City on day two.  Day three would have been Salt Lake City east to Cheyenne on I-80. That did not look like a good plan since by this morning all of the around-the-clock weather channel mavens were going crazy about the storm coming to the Midwest.

 

So we ate lunch and then hit the road at 12:45 PDT after deciding (with the help of the cameras at Snoqualmie Pass) to go I-90 east toward Spokane.  And that is where we are.  We are a couple of miles into Idaho at a Sleep Inn.  We had dinner with a couple of Kent's friends from the Corvair world and are now seriously thinking about getting some sleep.

 

Oh, did I mention that the trip across I-90 was through rain the entire way until we got near Spokane and then it became snow. Which is still coming down.  What's as adventure without some hardship?

[watchamakalit]

Sounds like the setup for a fun adventure.  Hope all goes well on your return to the Hoosier state.

[Salvagedcircuit]

Aww yeah, nothing like a road trip in the MJ

[jamespwsullivan]

Day Two

1/4/2025

8:30 MST

We made it to Bozeman, Montana.  We had planned to go as far as Billings which would have involved some night driving, but the worsening conditions on I-90 made the decision to stop an easy one.  It looks like tomorrow will be good with a possibility of some snow early.  We are shooting for Rapid City, South Dakota and if we make that we are pretty much on track with our average goal of 400 miles per day.  We are one for two with our goal of no night driving. LOL  If the National Weather Service's forecast stays close to what it is tonight we may stay ahead of the storm to the west and north of the storm to the south.  I-90 still looks like the best shot for the next day or two.

 

The truck is running great! Over all the passes on I-90 with no struggle. Downshifted to third manually a few times and could run @ 50-55mph on the steepest climbs. Engine coolant and trans coolant temps well within expectations and quick recovery. We can run at 75 mph (25-2600 rpm in overdrive) on the flats. It's no issue at all running 65-70. Kent is excited that 4Hi is available. I am too since the streets in Bozeman have not seen a plow recently.  Dinner at Ted's Montana Grill…in Montana! 

 

Here's a little more about the truck. The first thing that got swapped out in it years ago was the Dana 35 rear end. Now it has a more than adequate Dana 60 with the Metric Tonne springs.  We added a rear sway bar after removing the spare tire carrier. That also made a place for a Derale transmission fluid cooler with a switchable fan.  The front end is now a Currie Enterprises Dana 40.  It needed some customization  but it's a high pinion brute with disc brakes.  Speaking of disc brakes, the rear has a kit from Custom Performance Products - basically the '80-'85 Cadillac Seville caliper swap - and we added a tunnel mounted (like the Cherokee) e-brake with some universal cables and some interesting routing.  The NP231 is an original AMC branded unit and is the only thing in the drive train that is original.  Tomorrow - info about the engine.

[jamespwsullivan]

1/5/2025

9:00 PM MST

Today started off with a bang.  The temperature had dropped quite a bit overnight and both door locks were frozen.  Due to the timely assistance of the overnight staff at La Quinta Inn we were able to use a hair dryer and a long extension cord to get the locks working and get the truck ready to go.

 

We split the driving up a little differently.  I drove the first half and Kent the second.  Approximately 550 miles today which puts in the 400 mile per day goal we had hoped to meet.  One notable stop was at a Truck / auto stop at the Big Timber exit on I-90.  It seemed to be out in the middle of nothing but that place was hopping.  I would guess it's a bit of a hub for the surrounding homesteads and ranches.  The roads were in really good condition especially considering that last night we stopped because they were turning to crap.  Kent talked to a couple that had come in about an hour after we did and they said the highway was like an ice rink.  More affirmation of our choice to let go of the day's goal of reaching Billings.  We had quite a bit of elevation change considering that the view of the road from the windshield seemed pretty level.

 

I promised information about the engine in this truck.  Let me say that one thing I have learned is that not all years of inline 6 cylinder 4.0 liter engines by AMC or Chrysler are the same.  Who knew?  Back near the beginning of this project I had an opportunity to purchase a 4.0 from a 2003 TJ wrangler and an AW-4 automatic transmission from a different Comanche.  I found a shop that seemed to understand that I would keep the Renix Multi-Point-Fuel Injection system that was stock for the 1987 model but that it would be adapted to the later motor.  Sounds simple? No.

 

Some of this is probably out of order but that's the way my memory works.  I won't relate the entire history of this engine here (you can ask questions if interested) but I will say that when my brother and I began to really try to get this MJ on the road as a usable vehicle, we fought everything from really poor running (lots of sensor replacements), adjustments (thanks cruiser54 and lots of other folks on this forum) and troubleshooting exhaust leaks.  We were beating our heads against the wall because we simply could not beat the overheating issue.  Radiator replacements were made. We realized that the head was no longer flat (after the engine repeatedly overheated on the trip up from Florida) so we took it to a local machine shop and hat the head flattened and the valves done. We got it running OK but knew that more needed to be done.  It was still overheating. At one point we flushed the system more than a dozen times and thought we had gotten it as clean as it would get.  It was still overheating.  My brother and my nephew got out the borescope and started looking in the spark plug holes and the cooling passages they could access.  They used magnets and pulled out huge amounts of iron that had clogged passages and simply produced obstacles to the designed flow of coolant.  At the same time we bought a Cold Case two row all aluminum radiator, upgraded the water pump to a more modern design of the impeller, and installed a Hesco high flow thermostat housing (with two places for temp sensors.)  And it still seemed to be overheating. But we found that the ECU temp sensor (on the side of the block) had failed.  Nick of Renix Engine Monitor fame told us that when that sensor fails the ECU defaults to a value of 242 degrees.  We changed out the sensor...  Voila!  Now the thing wasn't getting anywhere near overheating.  In fact, the system was over-cooling.

 

More on the engine, over-cooling and overheating, and the final fixes tomorrow and the next day.  I have no idea if anyone is actually reading this but at least I am getting some of the project history documented.

 

Last entry from the Mountain time zone…  On to Sioux Falls tomorrow.  It should be a smooth ride still way north of any crazy weather.

[watchamakalit]

If no one else is, I have been reading along. Sounds like the makings of food memories to me. I would love to road trip In an mj. Alas I am married and my better half prefers the camper.....

[89 MJ]

No clue how long you’re staying on I-90, I know you can take I-35 south through Iowa when you get to Albert Lea, MN, but the roads are great here along I-90 in this part of WI

[jamespwsullivan]

5 hours ago, 89 MJ said:

No clue how long you’re staying on I-90, I know you can take I-35 south through Iowa when you get to Albert Lea, MN, but the roads are great here along I-90 in this part of WI

Turns out Sioux Falls was a pessimistic goal. We are pushing on to Albert Lea for the night. The highway has been extremely dry and clear and I'm glad to hear you're seeing the same. We just left Mitchell-Culver's fix- and had also stopped at Wall Drug for 15 minutes. My brother is driving now so I may take a nap.

[GonzoTheGreat]

1 hour ago, jamespwsullivan said:

stopped at Wall Drug for 15 minutes

Did you have a donut?

[89 MJ]

4 hours ago, jamespwsullivan said:

Turns out Sioux Falls was a pessimistic goal. We are pushing on to Albert Lea for the night. The highway has been extremely dry and clear and I'm glad to hear you're seeing the same. We just left Mitchell-Culver's fix- and had also stopped at Wall Drug for 15 minutes. My brother is driving now so I may take a nap.

Glad to hear things are going well. I’m 8 miles north of the West Salem, WI exit. If you need a hand with anything around there, feel free to drop me a PM. 

[jamespwsullivan]

2 hours ago, GonzoTheGreat said:

Did you have a donut?

Duh. Maple iced. Delicious.

[kentsu66]

2 hours ago, GonzoTheGreat said:

Did you have a donut?

You're darn tootin'. My third time having those delicious rings of heaven. It was Pat's first. We both settled on maple.

[jamespwsullivan]

1/6/2025

8:40 CST

Today was trouble free. The roads were clear and dry. We saw very little snow on the side of the road. A few miles at 65-70 mph and then the rest of the way between 70 and 75.  Fuel economy was down over a mile per gallon.  We were running this fast yesterday so the only thing I can think of that might affect fuel mileage is the much colder temps.  The automatic transmission fluid barely got the needle off the peg.  The ECU sensor temperature was pretty much the same as yesterday moving between 179 and 187 degrees on the highway.

 

We had planned to get to Sioux Falls today and then head to Madison tomorrow.  We got on the road early and even with a stop at Wall Drug (mmm, donuts!) we made great time to Mitchell, SD, had lunch at Culver's (one place on my brother's list of restaurants to visit when he is back in the Midwest) and then decided, what the heck, let's go on to Albert Lea, MN!  It's just another 250 miles after all.  Somewhere in that 3+ hours I realized that we could make Indianapolis in just one more day if we plotted the trip directly there instead of through Bloomington, IL (which was our latest plan to stay north as long as possible.)  Apparently the roads are good in Indianapolis so that's our goal for tomorrow.  All we have to fear is low temperatures and it's a lot warmer there than it is here in Albert Lea.

 

Speaking of temperatures…

It seems reasonable to assume that the iron that was in the cooling passages was the result of the truck sitting in south Florida for years without being driven.  There's a story about finding some rust inside the Dana 60 rear end housing and it seems that the cause was likely the same for that issue.  No circulation of the engine oil or coolant while it sat and the same for the differential lubricant.  Both of these issues have been addressed but not without some stress during the diagnosis and certainly some cost in dollars.

 

So, is the cooling system for the engine doing its job too well?  I don't think I mentioned that one of the things we tried to address the overheating was to convert to open cooling.  I actually agree with the guys who say that a good working closed system is fine but we were getting to the point that we would try anything that might make a change.  Once we figured out that the overheating issue was resolved (see previous post about the bad ECU temp sensor) and we were getting good readings, the funny thing is that the engine was not getting up to temperature.  The REM was giving the reading that the ECU was seeing and operating with, the GlowShift gauge on the A pillar was giving us a temp from the thermostat housing, and the dash gauge was also giving us temps from the thermostat housing.  Regarding the latter, this head and block are from a TJ and do not have a boss, threaded or otherwise, for the gauge sensor at the firewall end of the head.

 

Then I learned more about auto parts store thermostats.  A friend is a car guy from way back and has a fair amount of experience.  He said that he has heard and read that as many as 75% of parts store t-stats fail in some way.  We had already replaced one safety stat that had immediately failed open and so decided to replace the one in the housing with a Robert Shaw.  In case you are wondering, yes they were all 195 degree stats.  It appears that the one we just replaced was opening way too soon and the engine was not getting to the temperature it expected.  It was running OK but the overcooling was still a concern.  The Robert Shaw seems to be working the way it should, but the engine still runs a little cool I think.  When this trip is completed and I go back to work to make some money, I expect I will do a bit of experimenting with some of the concepts outlined by HOrnbrod and GoJeep regarding restricting the coolant flow.  See here:

https://comancheclub.com/topic/51005-using-cooling-system-restrictors-to-stabilize-temperatures/

And here

https://gojeep.willyshotrod.com/HowtoRadiatorRestrictor.htm

 

And more tomorrow on how we got this 4.0 to run the way it should.

[jamespwsullivan]

1/6/2025

8:40 PM EST

Well, we made it to Indianapolis. Another 500 plus mile day from Albert Lea, Minnesota to Indianapolis with no major snow in sight until we were just inside the I-465 loop on the northwest side.  Clear roads, clear sailing.  We even had sunshine most of the way.

 

Technical stuff - I noticed yesterday that our mileage was down and thought it might be due to the lower temperatures but wasn't really on solid ground with that hypothesis. Today I was watching the REM (Renix Engine Monitor - nickintimedesign.com) and the O2 voltage was only swinging from 1s to 2s instead of what I usually see - a swing between 1.x and 4.x volts.  Now if I have this right the lower voltages and shorter swings the sensor was reporting to the ECU meant that the ECU was continually attempting to enrich the mixture.  That would certainly have a negative effect on the mileage.  More research is needed, but this makes sense to me after a day of driving on the highway.

 

One of the items that had been on the list for the MJ for a long time was to fix all of the exhaust leaks.  By the time we addressed a lot of other things it wasn't just the leaks that needed to be fixed.  We started with the muffler and catalytic converter. We added in a new tailpipe for good measure.  I was planning to use a reputable muffler shop in Kirkland, WA based on the experience of my brother.  I decided to switch that up and go with a family-owned and operated garage in Redmond called Autosys, Inc.  Mike and Calvin had worked on my truck in the past and I was (and am) really impressed with their integrity and desire to complete a project and get the customer exactly what is needed and expected.  Once the cat, muffler, and pipe were replaced, Mike did a smoke test from the tailpipe forward and called me with the bad but not unexpected news that the exhaust manifold had a couple of pinhole leaks.  To be fair, the exhaust manifold was the original Renix style if not the actual original part.  Of course, this was an opportunity to see if there was a better than OEM replacement.

 

The accepted opinion is that the original manifolds were prone to cracking.  This truck had not spent much time offroad so the engine hasn't been twisted around stressing the exhaust system a bunch, but why not see if something else might give me a little more insurance.  It also seems that finding a good quality manifold is tough especially with a lot of the overseas imports that are currently available.  I did some research and found that the factory revision of that manifold had some accordion-type expansion joints in the areas that are likely to crack.  Well, that wasn't good enough. I wanted something even better. So I found another option that had additional reinforcement.  I bought it and gave it to Mike.  He tried like heck to install it but couldn't make it work.  It would not fit with the Renix Intake manifold.  Heating and even a little hammer work were unsuccessful.  Huh…  We trucked it back to my brother's garage to regroup.  Clearly I needed to get a different manifold.

 

The next steps are a little hazy at least in the order they all occurred. We decided to upgrade the intake manifold and then obtain an exhaust manifold to match.  Nick Risley has a really good YouTube video (https://youtu.be/0XXZRt9e4Vo?si=JxwEPpk89CPFxUdM) on this process so I went to the salvage yard and got a manifold and some other bits and pieces.  Several days later the manifold was installed and the truck was back at Autosys.  They installed the exhaust manifold, modified the front pipe (or maybe modified a new pipe that I supplied - hazy…) and all of a sudden the engine was running again.  Sort of.  We couldn't get it to idle correctly but after some trial and error and some more research we identified the culprit as the Idle Air Control and fixed that issue.  More stuff happened and then I got to take a test drive.

 

It is a different truck.  All of the symptoms of poor running are gone.  Matching the 2003 block, the 0331 TUPY head, the intake manifold from a 2000 Grand Cherokee and an exhaust manifold appropriate for the rest was the real solution.  The only things Renix are the inputs and outputs (sensors and controls) and the ECU.

 

If you have any questions about any of this please comment.  I may take a couple of days off but I will make this into more of a true build thread by listing all of the things that have happened to this truck since I bought it in 2011.  I might even have some pictures!

[89 MJ]

I look forward to the pictures. Glad you made it back and that it was smooth sailing. 

[Pete M]

long trips in old trucks are a blast   especially when all goes well.  

[watchamakalit]

Glad to see it was a success. I am now officially jealous and looking for a reason to take a long trip in mine. Lol