1989 Eliminator

yeah I'm in the same 2wd situation as you. Lights are nice!

keep us posted on the status of your problem!

To me this sounds like a major vacuum leak somewhere. Is this ECU brand new or used? The pins inside could be loose and when you brake they disconnect. Try and drive your truck down a road and lightly tap your ECU. If it sputters or wants to stale then it is your ECU.

actually just more noise from the pump as it spins faster without the resistor. Fuel pressure is regulated by the fuel pressure regulator. The ballast resistors used on old chryslers and other old stuff was to allow 12 volts to the points on canking and reduce it to 8 volts on running so the points would last longer. Right, the pump works harder. I thought that was my issue too but it was my CPS

I agree. Test and if so, replace the CPS with a Mopar part, not an auto parts store special. By small chance that weird hissing noise could be caused by the ballast resistor located right next to your air box. It is a ceramic looking piece That is what controls how much current goes to the fuel pump. Less resistance, more current, more fuel pressure since the pump is working harder. These used to go all the time on older Chryslers. Could need a replace... I still believe it is the CPS. Go to Cruiser54's renix tips in the DIY section.

If you do end up getting a newer radiator, I would strongly recommend a dual core instead of a stock single core radiator. You will never have problems overheating and is a well worth investment.

I had the same issue as you. This coolant temp. switch is located in the radiator as you have it shown. This detects the temp. of the coolent and is what triggers the aux fan to turn on when it get around 230 deg. The plug you are talking about in the engine block is located in the back right corner on the top, right next to the valve cover. This plug does not have anything to do with the aux fan. This only operates your temp. gauge on the inside. Things I did to solve this issue... I replaced that plug. (bought it from autozone) Replaced the relay that is for the aux fan. This I believe is what helped the issue. I refreshed my grounds which could have played a factor. Make sure you do not have any air at all in your system. If air is hitting that switch and not coolant, it will not work. This also will cause overheating. I also cleaned the contacts on all my electrical connectors. Good to do anyways I believe there is a fuse, but not 100%. If there is, it is under the dash by parking brake pedal.

its charging too much because she wants some light bars and a winch to power!!

Compliments from Biotex

What I did was take my spare set of keys and used a lot of black tape to hide them on the rear brake light connector. When you do this it looks like you were doing some sort of electrical work and just taped it! When you need the keys, just take the tape off.

Correct. There is very little space between the air box, washer bottle, and booster. I do not think the wash bottle would fit even with a small spacer. I'm sure you could make room somehow but the pedal is not noticably higher. I bought my fittings from a local auto parts store. Autozone... Any store would have the fittings. The vacuum hose goes from the front of the booster to the intake manifold? I am not sure if that is what you are asking. And ill post more pictures of how I hardlined from the MC to the valve.

My dad worked for a medical supply company and he got to know a guy that wasnt doing too well but had a 1989 garage kept MJ Eliminator with 32k on it. I at the time was 16 years old and looking to get my first truck. I actully was looking for an MJ becasue I seen one on the road and got really interested of how unique it was. Well, the old man that owned the MJ died from health and his wife now owned it. But she had her own car so she had no use for the MJ. She was also very old and well... did not know what to sell the Jeep for... I went and looked at the MJ for the first time and it was PERFECT. When I asked for a price I could not believe she said $2000 for a brand new MJ Eliminator. My jaw dropped! I basically stole it from her. So of course I bought it and my first truck was an MJ and I bought with my own money.I have been driving it ever since and couldnt be happier.

1996 XJ brake booster and MC Here is my brake conversion... http://comancheclub.com/topic/39437-1996-xj-dual-diaphragm-brake-booster-conversion/

Dual diaphram brake conversion upgrade! http://comancheclub.com/topic/39437-1996-xj-dual-diaphragm-brake-booster-conversion/

$3.89..... depressing

You could try upgrading your body grounds. If there is a bad ground that could be apart of it. If you want I have a manual at home and I can send you pictures of the wiring diagrams. I can possibly help ya diagnose it!

Maybe some of the channels inside the engine are plugged? Try taking out the coolent plug on the exhaust side of the engine and letting all the coolent and gunk drain out?

Just wrote my post on how my conversion went! http://comancheclub.com/topic/39437-1996-xj-dual-diaphragm-brake-booster-conversion/

The upgrade... AWESOME! I have at least double the stopping power than before. It took me around 4-5 hours. Well worth the upgrade. :driving: Before I started I took out the wash bottle and air cleaner box. Now to start off, I took off the brake switch from the pedal assembly. Then loosened the four nuts that hold the booster to the fire wall. Next I took the brake lines off of the old MC so I could pull the whole booster MC assembly as one unit. Now that I have the old booster for reference, I started the small modifications needed on the new booster. I drilled out a 5/8 hole in the new push rod and filed around the hole until the small bushing could fit nice and snug. Then came to grinding the flat on the rod. I took a grinding wheel and tried to make it as perpendicular as possible to the axis of the push rod but it does not need to be perfect. I grabbed a set of calipers and measured the distance from the edge of the plastic bushing to the flat. This told me how much to grind. Now come to find out after the project was all said and done... I did not have brake lights when I hit the pedal. Which meant I ground down too MUCH. Grinding not enough will make the lights always stay on. So, to fix this issue, I took two pieces of duck tape on top of each other and put them on the flat of the push rod. Then I had brake lights. The distance from the hole to the flat is that critical. It only took about a 1/16" difference so they would come on. So if you do grind down too much, not a big deal. Now that I finished the modifications, its time for installation. I found I did not really need to bend the lip of the firewall for it to fit but I did anyways... Since it is a bigger booster, the MJ distribution valve is very close to the booster. I somewhat bent the valve on an angle so I could get the new lines to it. From there I made my new lines. I did not get the old WJ flex lines but that would work too. I just had regular brake line. Now, it was crazy how it all turned out but I had four different fittings on each line. On a side note, the NEW MC has bubble flare fittings and the old MJ valve has double flare. On both lines I had a bubble flare on one end and a double flare on the other. On one line there is a M12-1.0 bubble flare fitting and a 7/16-24 inverted flare fitting. The other line has a M10-1.0 bubble flare fitting and a 1/2-20 inverted flare fitting. What I did was buy one 40" long bubble flare brake line, cut it in half using the pipe cutter, and slide on the new fittings and double flared both of the ends. Make sure the yoke and adapter peice is straight and square when flaring....... had a little trouble.... Hooked up the lines and bent them accordingly. ^^^^^The Fitting on the left is the M12-1.25 bubble flare. The one on the right is the M10-1.0 bubble flare.^^^^^ ^^^^The fitting on the left is the 7/16-24 standard. The fitting on the right is the 1/2-20 standard.^^^^ There are some fit issues: :rant: Do not have the brake lines stick out too much or else they will hit the wash bottle. The wash bottle also needs to be moved to the left about one inch because it hits the new booster. The MJ distribution valve is very close to the booster so you can move it or whatever you like. My brake pedal is a little higher than before but I barley notice it. I bleed the lines by going to the RR then LR, RF,LF. Then I did the RR again just to be sure. I did not do the weird bleeding procedure like many people say. My brakes are amazing so they are bleed correctly. I also did it with my truck not running. Side Note: My booster did NOT come with a spacer and worked fine. Installed the brake switch (mine has two hook-ups on the switch because I have cruise control). Flaring Tool Learn how to use the flare tool the right way.... I had a little trouble. Line Cutter Then I was on the road braking like a corvette!! :banana: This upgrade is a must do. It is like the new booster was made for this truck. Again, I have a 1989 MJ and used a booster & MC from a 1996 XJ. Ask for more pictures or questions!! :thumbsup: :wrench: Here are some other links for different view points. http://www.jpmagazine.com/techarticles/drivetrain/154_0810_cheap_jeep_brake_system_upgrades/ http://www.4x4wire.com/jeep/tech/brakes/xj_wjbrakes03/booster/ http://comancheclub.com/topic/24430-wj-booster-and-master-cylinder-upgrade/

Do the dual diaphram brake booster and MC upgrade!!!

I know there are many threads that explain this procedure but another won't hurt from someone elses experience. So, this weekend I am starting the dual diaphragm conversion on my 1989 MJ. To start off, here are the tools and equipment I have so far: 1996 XJ Brake Booster and Master Cylinder (bought off of JC Whitney) $170 (2) 3/16 diameter bubble flared with 10mm fitting brake lines STANDARD flare tool (rented from auto parts store) (1) 12mm thread 3/16 diameter line, fitting (1) Vacuum Tool (4) 10mm stop or lock nuts (1) Line cutter The four 10mm nuts are for the brake booster. The other two bolts on the other side can use the nuts off of the stock MJ booster. I chose to buy the bubble flare lines because the 1996 MC takes bubble flare ends and not double flared. The MJ distribution valve body DOES take double flare though. So, I am going to have to flare one end of each line using the standard flare tool. Also, one of the ports on the 1996 MC takes a 12mm fitting which I will have to slide on the line before flaring again. 1996 XJ brake booster 1996 XJ master cylinder currently being bench bled using vacuum tool Vacuum tool This tool made the bleeding process a little easier. There are many ways to do it. Putting each of the hoses from both fittings into the bottle and pushing the rod in, will have the same effect. I did both methods just to be sure. That is where I am at right now. Tomorrow I will start the upgrade!! :wrench: Also there will be lots of more pictures! :clapping: :thumbsup:

Both the lines going into the 96 MC are bubble flared. Is the connections on the MJ distribution block also bubble flared?

Checking the CPS and TPS is usually a good start to this problem. Check Crusiers tips for instructions. The ground could need upgrading since the grounds on the MJ's are not that great. http://comancheclub.com/user/2838-cruiser54/ Go to his page and check out his tips

I doing the same thing as you but just upgrading my master and booster from a new OEM 96 XJ. I am actully doing this conversion hopefully this weekend and I will post pictures of my process for future reference. Probably a dumb question but I have never done this before.... Do I have to bleed my new master cylinder before installation?

Do you have an aftermarket air filter?