BuckB91XJ

Yes, I did read through all of Cruiser's stuff. I also did a lot of reading on the NAXJA forum, Jeep forum and just about every other article out there on the "Interweb" concerning testing, adjusting and potential problems with RENIX XJ 4.0 sensors, high idle, rough idle, no start, stumbling and engine electrical issues.
I have had a little bit of experience with all of those issues from helping my son through them on his 87 RENIX. I know you can get yourself running in circles and replacing a lot of components that aren't bad if you try to use normal automotive electrical logic in your troubleshooting. With my background in aviation electronics and electrical and NOW knowing that these jeeps have the same issues that airplanes built in the 70s and 80s did, with the use of crappy wiring, electrical connecters, terminals and components, it will be easier for me to take an objective and educated approach to fixing my new red jeep.

BuckB91XJ

So, I crawled underneath the Jeep and took a good look around the bottom of the motor on all sides. I figured out there is a pretty much bad oil leak where the Oil Filter Adapter meets the engine block. There is also more oil leaking out of the Valve Cover than it is holding in. I went and ordered the parts today. My local parts counter didn't have them in stock. However, they will have them tomorrow morning. I bought a new "O" ring for the oil filter adapter and I bought a new "Permadry Plus" type Felpro valve cover gasket. Hopefully swapping out these gaskets will stop the cascade of oil down the sides of my motor. I also learned another really cool trick to slow down the oil blowing out of the front valve cover CCV breather and into the air intake.

So you pull the valve cover off and flip it upside down on a work bench. Then you remove the metal tubes that are under the breathers inside the valve cover. You take a hack saw or cutoff wheel and cut about 1 inch off the end of them and then drill a 1/2 inch hole in the side of each. Then you put them back in the valve cover. There is no need to hunt down new gaskets for the little tubes. They are not necessary. Tomorrow when I do the work I will take a few pics and post them.

BuckB91XJ

The guy who wrote the story about the valve cover breathers was a service manage at a Jeep dealership back in the 80s and 90s (the hay day of the XJ). After the mod is done the breathers work just as good but they don't shoot as much or any oil into the air intake anymore.

Once I get the oil leaks all fixed then I will get busy fixing all the suspected NASTY engine electrical grounding points. Once the motor is holding it's oil inside it will actually be worth the time and effort to clean the electrical stuff up. Once that stuff is cleaned up I could possibly see better engine performance from sensors working better from getting the proper amount of tron flow through them.

BuckB91XJ

I finally remembered where I'd read about the Valve Cover Breather Modification. It was in "Cruiser's Renix Tips". Here are the pictures of the Mod from his write up. I will take pics and post them on this thread after I perform the Mod. on my valve cover tomorrow. You can see the important thing in the first picture, though. The difference in the length of the tube before and after it's cut and the 1/2" hole drilled in the side. I wish I had learned about this little mod. years ago. My 91 XJ's HO motor was constantly belching oil into my DIY cold air intake. I hated that! Can't wait to do this to my new 87 Renix Jeep. If it works good I might even pull the valve cover off of my old 91 HO motor which is now in the 96 XJ Country and do the mod. to that motor, too.

zte87

So buck when do you plan on adding some altitude to it?

BuckB91XJ

As soon as I get a weekend where it's not pouring rain or freezing cold. My garage is a mess so I will be doing it in my driveway. I also need to do a few things with the axles before they can go on.

BuckB91XJ

I started out today by taking the oil filter and oil filter adapter off. MAN!!!! what a mess. There was that oil and road grime sludgey mixture about a 1/4" deep from the oil filter adapter back and all the way down to the oil pan....and you guessed it the starter is right in that area and it was completely corroded and covered in sludge. The starter was so bad I just removed it and cleaned it up on the work bench. I also discovered as i was removing the oil filter adapter and the starter that the wiring harness on that side of the motor was completely mis-routed and of course since it was hanging loose in that area it too was completely covered in sludge. Here are a few pictures of my handy work today. I was totally expecting the sludgey mess from the oil filter adapter leaking...and by the looks of things it had been leaking for awhile but, I really couldn't believe that wiring harness that is supposed to be tucked in tight to the block behind the distributor and the oil pressure sender, was just left hanging like it is in the picture. So, you know me being the electrical guy, I cleaned the electrical contacts on the starter and the oil pressure sender. I cleaned up the wire loom cover and tomorrow after I put the starter back in I will reroute that wiring harness where it is supposed to be. I think that will really help the right side of the motor look much cleaner. Well, that along with the 5 cans of Carb. cleaner and much scrubbing with a wire brush and tooth brush that I did to clean the engine block up.

BuckB91XJ

Here are a few more pictures showing how nasty and leaking the valve cover gasket is. I also snapped a pic of the oil filter adapter cleaned up and re-installed.

BuckB91XJ

Here are the before and after pics of the starter. It was so nasty and the connections were so corroded and oil soaked I really don't know how it was still working.

OleBlue

Sooooo, gonna have a lifted jeep by the end of the weekend?

BuckB91XJ

Not a chance!!! It's supposed to pour down rain here all weekend and I have to do it in my driveway.

BuckB91XJ

I did get some more of the clean up down in the engine bay on my Jeep. I was able to do most of that in the garage. It got the wiring harness from the battery to the oil pressure sender and the small wire to the starter cleaned up and ran.

I also did a little swap between the red Jeep and my white Jeep. The white jeep will probably never see off road or weird angles.....and the battery box was cracked and the battery hold down was completely missing. So I put the cracked battery box and the battery out of the red jeep in the white jeep. The battery box is good enough to keep the battery out of the fan as long as the jeep stays level. I put my awesome Duralast Gold battery, perfectly good battery box and battery hold down in the red Jeep. So, now I have my known good battery in my new red jeep with good battery box and hold down all nice and secure and ready to go wheeling.

I also removed the battery cables and got them all cleaned up. I also removed the dipstick tube engine block grounding stud and cleaned it. Then I ran out of daylight.

Oh, I also removed all of the extra length that was left on the heater hoses last time last time they were replaced by the PO.

Tomorrow the battery cables will be put back in. The starter will be put back in. The dipstick tube engine block grounding area will be cleaned the rest of way. The sensor grounds that also go on that stud will be all cleaned up and the stud will be put back on the motor and tightened up. Hopefully I will have the Jeep running and driveable. Then I can replace the valve cover.

I also took a picture of the cleaned (+) battery cable clamp after cleaning and the (-) battery cable clamp before so you can see how nasty they both were before cleaning.

BuckB91XJ

I also need to get the valve cover cleaned up an valve cover gasket replaced. Then I can put the new oil in and it all should stay on the inside of the motor, now.

BuckB91XJ

I finished the cleanup of the battery cables and the dipstick engine grounding stud. I polished up all of the electrical connections and put them all back together securely.

Then it was time to clean up and come inside and watch the Hawks / Saints game. The Hawks beat them just like I figured they would. The game was much closer this time just like I figured it would be. The Hawks had to work a little harder this time to beat the Saints. The Beast had an awesome game. Almost 150 yards rushing!!! Now, they will be playing the winner of the Niners / Panthers game, at our house next week for the NFC Championship game.

After the game was over, I went back outside. I started removing the valve cover so I can replace the gasket. I really love where they mount the cruise control vacuum actuator in a RENIX Jeep, NOT! They mount it to the firewall directly over the rear of the valve cover. So, that had to come out before I could get the valve cover off. The cruise control doesn't work on this Jeep anyway....yet. Yup, I am going to get it working even though it is a wheeling rig, I have to have everything electrical working on my vehicles. I cleaned up the engine to firewall grounding strap, I cleaned up the water temperature gauge sending unit...which was only finger tight and had been leaking as much water as the valve cover was leaking oil. I also cleaned up the valve cover bolts. Tomorrow I will do more cleaning on the head when it is daylight out. I will also clean up the valve cover and it will get a coat of semi gloss black paint.

BuckB91XJ

I started today off by doing more cleaning around the valve cover area. Thus motor had really puked a lot of oil out and all over the place since this valve cover gasket has been bad. I also did the final cleaning and polishing on the rear motor to firewall ground and put it back together. I cleaned up the valve cover inside and out and gave it a nice 7-8 coats of semi gloss enamel paint. With the hardware all cleaned and polished up it really turned out nice. While I was waiting for the paint to dry on the valve cover, Built up a grounding strap and installed it between the (-) battery cable and the closest 10mm radiator support bolt to the battery. I also built up another grounding strap and installed it between the firewall grounding bolt and the farthest rear heat shield bolt on the intake manifold. Once the valve cover paint was dry I installed the valve cover and I poured 6 quarts of fresh 10W-30 oil into it. I also filled the cooling system up with 50/50 anti-freeze fluid. I did one more check all over the engine compartment and then I tried to start the Jeep up. I got nothing except clicks. When I re-installed the starter yesterday I made 2 rookie mistakes. (1.) I attached the large red battery wire onto the wrong terminal and (2.) while I was tightening it I over tightened and heard a "crack" sound and a large chunk plastic dropped to the ground. Then when I tried attach the battery cables the starter started turning and wasn't engaged to the motor. I knew I'd screwed up at that point but I was hoping the solenoid was okay even after I'd over tightened the nut on it. I checked battery voltage and it was 12.31 at the battery. I ohmed out all of the cables so I now know I broke that stud loose inside the solenoid when I over tightened it. I pulled the solenoid off of my other starter I have in the garage and cleaned it all up. I will pull the starter off tomorrow, swap out the solenoids and re-install it. Then the Jeep should start up and run like a champ. Once I have it running good, the next steps in my build will be to get my axles cleaned up and fixed up. Then the lift axles ans tires will go on.