ZJ: 4.0 header install questions

[TOOLman]

It finally looks like there's a chance that I'll get my Kolak exhaust installed. I talked to a friend of mine, who's a skilled mechanic. He's also a good welder, which I'm not.

Anyway, we were looking into the engine bay trying to figure out what needed to be removed for this installation. He suggested using a small hoist that he made for lifting the engine of his old VW Golf. The idea was to rig it up over the engine and let the intake manifold hang from the hoist, thereby eliminating the need for disconnecting everything. Do you think this is practically possible?

Also, I think we'll have to disconnect the fuel line in any case. The instructions mention the need for a special tool for this. Tools and parts for American vehicles are very difficult to come by here, since they are fairly unusual. Is there any way to disconnect and reconnect the fuel line w/o this special tool?

Finally, a question for those of you who have the Mike Leach tailpipe for the 4.0. The hanger on my tailpipe is facing the other way, compared to the stock tail pipe. This will make it more or less impossible to use the exhaust tip (Angelus Plating), unless we cut it out and reattach it in the opposite direction. Is this the way all Leach tailpipes are, or is there something wrong with mine?

TiA

[dave]

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It finally looks like there's a chance that I'll get my Kolak exhaust installed. I talked to a friend of mine, who's a skilled mechanic. He's also a good welder, which I'm not.
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Excellent! You'll like it. :)

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Anyway, we were looking into the engine bay trying to figure out what needed to be removed for this installation. He suggested using a small hoist that he made for lifting the engine of his old VW Golf. The idea was to rig it up over the engine and let the intake manifold hang from the hoist, thereby eliminating the need for disconnecting everything. Do you think this is practically possible?
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I can't see how it would help but you might find a shortcut. The reason I say this is you'll need to remove quite a bit anyway and the manifold would just be in the way if it were hanging there. You need all the space between he valve cover and the wheel well to thread in the headers. My '94 intake only has ~8 vacuum/electrical connections plus the injector wires. Mark them with tape or velcro markers and get it out of the way. I shoot pictures in case a tag falls off but the connectors mostly want to go back where they belong anyway.

Oh, the fuel lines are bracketed to the driver side of the intake manifold. Remove the bracket early so you can drop the fuel lines down and get to the lower manifold bolts.

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Also, I think we'll have to disconnect the fuel line in any case. The instructions mention the need for a special tool for this. Tools and parts for American vehicles are very difficult to come by here, since they are fairly unusual. Is there any way to disconnect and reconnect the fuel line w/o this special tool?
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Yours may have different quick connects but mine are very simple. There's a white, tabbed, lock attached to each fuel rail fitting. Each fuel line has a black end that fits over this fitting and lock. The white lock then snaps inside the fuel line end. To remove mine I just put a rag underneath the lines, pinch the white lock halves, and slide the fuel line off.

Something to watch for is the large amount of fuel that remains in the injector rails. If you aren't ready it'll go everywhere when you remove the manifold. After you unbolt the manifold and before you lift it out, plug the rail fittings with something or tie them with a rag. (Caps made from fuel-line plugged with bolts work well.)

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Finally, a question for those of you who have the Mike Leach tailpipe for the 4.0. The hanger on my tailpipe is facing the other way, compared to the stock tail pipe. This will make it more or less impossible to use the exhaust tip (Angelus Plating), unless we cut it out and reattach it in the opposite direction. Is this the way all Leach tailpipes are, or is there something wrong with mine?
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I think my stock and Leach hangers both point to the back, but at least a foot from the tail. Must be a long exhaust tip! Still, an exhaust person should be able to cut off the hanger and reverse it without effort. Might be a good idea to leave the tip for last and use the hanger as is until you're done with the rest. The tailpipe/trackbar/fuel tank fitment is pretty close and the hanger is the pivot point.

Let me know if you have other questions. I'm no pro but it wasn't that difficult. Just time consuming. Mark things and take your time.

Here are my install notes (http://forums.jeepsunlimited.com/ubb/Forum19/HTML/005056.html) from the other board:

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Funny you should ask. I just finished cleaning everything up after installing my 4.0L Leach headers. "Ah'm tard. Think ah'l go home." The instructions Leach includes are fine. Still, it took me over 4 hours and chit-chat with a couple passer by's. It isn't complex but it's a little painful. Some of the bolts are tough to reach. If you don't do this stuff often and you work outside, start before noon and plan on the day so you have enough time.

I think Leach lists most of the tools but here are things I couldn't have done without:

1) Socket wobble or at least a wobble 9/16.
2) Metric sockets, SAE sockets
3) 6" and 3" extensions
3) open end 9/16, 1/2
4) At least 1 can of brake clean
5) paper towels
6) Big cardboard box, opened up, to protect your driveway from falling crud. Or not.

And you'll need a sawzall (or hacksaw and time) to cut off the old downpipe. That's about it. I think Leach's instructions cover most of it but they're over there and I'm sitting on this couch.

A couple steps I would add:

a) When you're about to loosen the intake/exhaust manifold bolts, clean the flange area with brake clean. (put cardboard on the ground underneath to catch the crud) You'll be staring in the engine so it's good to have the area somewhat clean.

b) Once you have the intake and exhaust manifolds out of the jeep, stuff a wadded paper towel into each intake/exhaust opening. (all the way in, with maybe a bit sticking out) You'll be using a gasket scraper/putty knife to clean the mating surfaces next and you don't want crud getting inside. And after scraping I shoot another round of brake clean to get the grunge off. The towels keep it outside.

c) Edit: (I forgot this one.) Before reinstalling the intake manifold you'll need to scrape it like you did the head surfaces. After scraping I used some TB cleaner to clean out the ports, inside the runners, and the injectors which are staring right at you. Be careful not to poke or prod the injectors. Squirting with TB cleaner is okay, but don't molest.

Oh yea, this is a good time to replace your serpentine belt so pick one up with the other parts. (4.0L Gatorbacks are ~$20 at carparts.com) You'll have the p/s pump off anyway. And you might consider a new O2 sensor since it'll be coming off too. Some people report seized sensors, and getting a new one lets you leave the old one on the old downpipe.
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Some pictures (http://albums.photopoint.com/j/AlbumIndex?u=666068&a=12296693&f=0) from my aborted documentation effort.

Good luck, and enjoy!
Dave

[TOOLman]

Dave - a million thanks for that comprehensive reply! I wish I could buy you a couple of beers for that! :beer:

Yes, it's a very long exhaust tip! I would fit (lengthwise) on the stock pipe, but not on the Leach one since its hanger points toward the front. We'll work that one out, though. It wouldn't even matter much if I had to leave it. It's 3.5", so it'll look more like a bus exhaust :)

Thanks again!
/Tommy

[dave]

Hey, I'll babble online for beer any day!

Let us know how it works. There are at least a few of us around here with that exhaust. You'll only be sorry you waited. :)

[Agent00ZJ]

Originally posted by TOOLman
Anyway, we were looking into the engine bay trying to figure out what needed to be removed for this installation. He suggested using a small hoist that he made for lifting the engine of his old VW Golf. The idea was to rig it up over the engine and let the intake manifold hang from the hoist, thereby eliminating the need for disconnecting everything. Do you think this is practically possible?

Yes, but I don't see a point- it will only be in the way and does not weigh that much. Just take it out to have more room to fit the headers in and get at the bolts.



Also, I think we'll have to disconnect the fuel line in any case. The instructions mention the need for a special tool for this. Tools and parts for American vehicles are very difficult to come by here, since they are fairly unusual. Is there any way to disconnect and reconnect the fuel line w/o this special tool?

The special tool is a standard fuel line disco kit. It just a set of different size/color plastic rings which you fit over the fule line inlet to push the line off. It costs < 5 dollars at any auto shop. They are not vehicle specific. You could probably get it off without it- mine came off pretty easy.


Finally, a question for those of you who have the Mike Leach tailpipe for the 4.0. The hanger on my tailpipe is facing the other way, compared to the stock tail pipe. This will make it more or less impossible to use the exhaust tip (Angelus Plating), unless we cut it out and reattach it in the opposite direction. Is this the way all Leach tailpipes are, or is there something wrong with mine?

Nothing is wrong with yours. It is the way all the Leach pipes are. The stock ZJ rear bracket came both parallel to the pipe, and perpindicular to the pipe. No rhyme or reason to it, some are one way some are the other. Just heat it and bend it, or better yet, cut it off and reweld it the right way.

P.S.-Make sure you retighten the header bolts after some driving. They loosen up after the headers get hot.

[TOOLman]

[Yes, but I don't see a point- it will only be in the way and does not weigh that much. Just take it out to have more room to fit the headers in and get at the bolts.

The idea was maybe not having to disconnect all those vacuum tubes and wires, but I see now that it won't help.


[B]The special tool is a standard fuel line disco kit. [...] It costs < 5 dollars at any auto shop.

I've never seen it in Swedish auto shops, but OTOH I haven't exactly been looking for one before, either.

[B]Nothing is wrong with yours. It is the way all the Leach pipes are. The stock ZJ rear bracket came both parallel to the pipe, and perpindicular to the pipe. No rhyme or reason to it, some are one way some are the other. Just heat it and bend it, or better yet, cut it off and reweld it the right way.

The stock one is parallel to the pipe, with the 'open' end facing the rear. The Leach hanger is facing the front, so it gets in the way of the long exhaust tip. If I decide to use the tip, we'll cut it off and reweld it.

[B]P.S.-Make sure you retighten the header bolts after some driving. They loosen up after the headers get hot.

Thanks for the tip. Just wondering how I'll reach them with everything reassembled again. Do you know what torque specs there are for those bolts?

Thanks for your input! A virtual :beer: for u2 :)

[dave]

Good point Agent. Definitely add that to the list. I've re-torqued mine twice since the install and will be making a final check before bolting the airbox down. Good to be safe. I've had header gaskets blow out before and don't want a repeat. The I6 re-do is evil.

[TaylorZJ]

Great write-up dave!! I have done this task 2 times(replacement header had a, never mind too long) and it was not too hard to do. A couple of additional tricks; you can bleed the 4.0 fuel rail. Somewhere in the top middle is a cap, unscrew it and either put rags or a small container and then bleed the fuel system from this point. It bleeds like a tire air valve, just be gentle. I recommend removing the injectors and replacing the O rings. This is inexpensive(about 6 to 12 bucks I think) but its a good idea, since you have to remove the intake manifold anyway. Before installing the new header, take the lower middle exhaust bolt and screw about a turn or two into the head. This bolt in a PITA to start through the new header pipes. Good luck!!!.......RT

[dave]

Great write-up dave!!

There's no better way to learn than by teaching, and then being slapped about the head for saying something stupid. :)

[b]
I have done this task 2 times(replacement header had a, never mind too long) and it was not too hard to do. A couple of additional tricks; you can bleed the 4.0 fuel rail. Somewhere in the top middle is a cap, unscrew it and either put rags or a small container and then bleed the fuel system from this point. It bleeds like a tire air valve, just be gentle.

Good point. Some need this relief step more than others. My check valve isn't very good so I just let it sit ~5min. which is enough to bleed off any pressure.

[b]
Before installing the new headers, take the lower middle exhaust bolt and screw about a turn or two into the head. This bolt in a PITA to start through the new header pipes. Good luck!!!.......RT

Good tip! That bolt is easily the worst of the bunch. Something I tried later that might help others is using ramps. Drive the front wheels onto ramps before starting the job. It means using a step for access to the engine top, but now you can get to the lower bolts from underneath. It definitely makes a couple of them easier after things are back together. Probably isn't worth it if you don't have a good/safe standing platform for the top work.

Dave