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34 minutes ago, Awesome said:

the big hose that goes to the bottom of the air intake box

You might be referring to the pre warmer. Does the hose have a spiral wire in it like a dryer vent hose?
 

If so, it’s to draw hot air off the exhaust manifold into the air box during initial start up to bring the engine up to temp quicker.

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1 minute ago, GonzoTheGreat said:

You might be referring to the pre warmer. Does the hose have a spiral wire in it like a dryer vent hose?
 

If so, it’s to draw hot air off the exhaust manifold into the air box during initial start up to bring the engine up to temp quicker.

 

Yes that. So it is indeed more emissions stuff that isn't needed. Thanks.

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There is no hole in the exhaust manifold for the pre-warm tube. It’s a shield that bolts around the exhaust manifold with a hose attachment neck, just leave it in place.

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1 minute ago, fiatslug87 said:

There is no hole in the exhaust manifold for the pre-warm tube. It’s a shield that bolts around the exhaust manifold with a hose attachment neck, just leave it in place.

 

Oh, lol. I hadn't looked into that tube. Thanks. If it's not actually pulling exhaust gas then I suppose there's no harm in leaving it in place.

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Another small update... finished pulling the exhaust manifold off.

Got a lot of carbon buildup in the exhaust ports. Valves aren't coked up too badly.

IMG-20240729-142316884-small.jpg

 

The manifold gasket was definitely leaking pretty badly.

IMG-20240729-151758824-small.jpg

 

I made the EGR blockoff plates. I forgot to take a picture of the one I made for the intake manifold. I'd mess with them more if I was making them for other people, but they were good enough for me.
IMG-20240729-151739617-small.jpg

 

This was that heater hose "T" connection on the '88 that I mentioned the other day.
IMG-20240726-151113378-small.jpg

 

I regasketed the throttle body today and cleaned up the manifolds. Made the block off plates. Tomorrow I'm going to go ahead and replace the freeze plugs while they are really easy to get to, clean the manifold surface on the head, replace the motor mounts, replace the belts and most of the hoses, then start buttoning stuff back up. I'm also planning on finishing getting the driver's side floor rust completely cut out. Haven't been getting much help from the daughter. I'm going to try to get her in the shop with me tomorrow.
 

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19 minutes ago, fiatslug87 said:

One gasket is both for the exhaust and intake.

Or were you being sarcastic?

 

Nope I looked it up and Eagle is right. There IS a gasket for the 2.5 that has only the intake manifold and no exhaust on it.

I already bought a regular gasket though.

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My buddy came over last night and we got a TON of work done on the '86 Comanche.

 

I flushed the entire cooling system with the freeze plugs out, put new ones in (old ones were actually fine as it turned out, but still worth it to be sure), then flushed it some more with the new plugs in. I pulled the radiator out. I put the intake and exhaust manifolds back on and hooked everything up. I used plenty of copper gasket spray on both sides of the new gasket, and I used red locktite on the bolts after using a thread chaser on the bolt holes. I torqued them all to 23ftlbs in the correct torque pattern.

 

Is there a vacuum hose diagram floating around on this site? I need to find one. I've got a couple hoses coming off the black vacuum pipe manifold thing behind the throttle body that broke and I'm not positive where one of them goes. The bigger one goes to the back of the airbox, but the smaller vacuum line goes to a 2-port rubber thing that isn't plugged into anything.

 

While I was doing all that, my buddy was finishing cutting out the driver's side floor. He's coming back tomorrow evening and we plan on getting the new pans welded in. The rust goes pretty far up the pedal box under the parking brake pedal, so we're going to have to cut in a patch panel under there.

 

I took the radiator to two different radiator shops today and they both told me it wasn't worth it to try to fix it. So either I order the $230 Crown radiator or I retrofit the YJ radiator I have laying around into the MJ. I test-fitted it yesterday and it will require heavy modification of both radiator brackets on the MJ. Doable, but I don't know if it will be worth it. The YJ radiator is quite a bit bigger.

 

I don't have pictures yet because we were very busy yesterday and my hands were too grimy. Then I was too beat when we were done. Will get pictures tomorrow.

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Driver's side floor prepped for pan:

IMG_20240801_161034588_1_small.jpg.5f67c7771f2c3620e4319876ffb3df29.jpg

 

Driver's side pan partially tacked in:

IMG_20240801_190647751_1_small.jpg.3ac0902ed8a41cb2adceeb0b6d95b254.jpg

 

Passenger side almost ready for a new pan:

IMG_20240801_184726625_1_small.jpg.d7be75196be0dd210f05cf0ccf57fde4.jpg

 

Did all that yesterday. I didn't get a lot done today. It's really hot now, so I only got the rear driver's side pan cut to size and fitted in place. The front pans don't need much fitting or hammering in order to fit right, but the rear pan will need a LOT of hammering due to the difference in the floor shape.

 

I figured out how to mount the YJ radiator without a ton of modifications. I'll take pictures of that while I do it.

We also figured out a way to modernize the engine vibration damper. I'll follow up with that later. I may get the floors done this weekend if I have the energy. I started back to work this week so I'm trying to finish the big jobs now while I still have the mental fortitude, lol.

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Well I had a nasty setback today. Feel like I wasted my entire afternoon. I was modifying one of the radiator mount brackets and building the support brackets I needed for the YJ radiator to mount in the MJ when I discovered that somehow I measured something wrong and the YJ radiator won't fit. It's too tall by quite a bit and a little bit too wide. It hits the passenger side frame rail if you try to drop it low enough for it to work. I must have measured thinking it would fit in front of the swaybar, but it won't. Guess I'm ordering one of the more expensive MJ radiators. :(

 

Also had my daughter pull the battery box out and found more metal that needs patching.

 

image.jpeg.72223e9c3f1acddf0a8399ae0935eb46.jpeg

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  • 1 month later...

I got the fenderwell under the battery box cut out and patched today. Much better if you ignore my crappy welds.

 

Worked on modifying the radiator I bought in order to make it fit. It won't. I'm not sure what to do now. My options are to modify the truck itself or just buy the Crown radiator and hope that IT fits.

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6 hours ago, Awesome said:

Crown radiator and hope that IT fits

If it’s for the 2.5L, I bought one and had no issues. I haven’t heard of anyone having this many issues with a radiator fitting. 2.5L radiator remained largely unchanged until the 2.5L was discontinued. 

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20 hours ago, 89 MJ said:

A grinder and paint makes me the welder I ain’t 

 

I'm a professional welder, which is why it's so embarrassing. :laugh: Turns out thin rusty sheet metal is hard to weld.

 

19 hours ago, eaglescout526 said:

If it’s for the 2.5L, I bought one and had no issues. I haven’t heard of anyone having this many issues with a radiator fitting. 2.5L radiator remained largely unchanged until the 2.5L was discontinued. 

 

I got it to fit, finally. I had to beat the frame flange up out of the way with a hammer. It's all installed with the proper shroud. I'm not positive the swaybar won't hit it. I may have to space the swaybar down away from it.

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Alright, picture time. Here's the modification I had to do to the frame flange:
IMG-20240909-210235623-small.jpg

 

Took the valve cover off as it was leaking pretty badly. I don't see anything wrong under here. Looks fairly clean, actually.
IMG-20240910-183810892-small.jpg

 

Valve cover is badly damaged from someone torqueing the bolts down too much. All of the holes are deformed and cracked.
IMG-20240910-183829670-small.jpg

 

New radiator and hoses installed, valve cover gasket install is in progress.

IMG-20240910-214204147-small.jpg

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