Replacing an 89 intake manifold with a 99??

[Shane]

I read in a past thread about throttle body spacers, some one mention swapping in a 99-01 intake maniflod. Could I do this to my 89 MJ? I have only had my mj for 1 month and I have found that doing upgrades on that model seem to be more difficult than a 92. Switching the manifold is it just a matter of taking on off and putting one on? Would this open a window for more improvements ie. cold air intake etc. Thanks

[Motion Offroad]

Doing the swap on a Renix motor (87-90) requires you to get creative with the throttle body itself. The Renix TB used 3 studs where the HO TB used 4.

 

So a Renix TB is not a direct swap to the newer style intake manifold. We've in the past made a small adapter plate that allows you to run the Renix TB on a HO intake manifold. You can also get creative and use the Renix sensors on a HO TB; but it does require a bit of modification as well.

 

Is it worth the hassle? I think you'll see good gains from doing so.

[Shane]

so this doen't require any engine removal? Just the throttle body and intake? After thiswould I be able to find a cold air intake? Are the mods a big hassel. thanks

[Motion Offroad]

Are you wanting to do this simply so you can run a cold air intake kit? The reason the '91+ intake kits won't work on the Renix motor is not due to the fact the TB is different; it's due to the fact of other stuff in the way.

 

Here is a '87-'90 intake kit; they are not hard to find. :D

 

http://motionoffroad.com/catalog/index. ... cts_id=554

[Eagle]

Keep in mind that the ports on the 87-90 engine are lower and shaped differently than on the HO engines. Swapping to the newer manifolds on the older engine is not a straight, bolt-on conversion. There's some adaptation required, and the result is still a compromise because of the mismatch in the port shapes.

 

The other consideration is, what are you looking for in the way of "improvements"? The non-HO engine produces more torque lower in the RPM range, and generally gets better gas mileage than the newer engines. The more you try to turn the old engine into a new one in pursuit of "performance," the more you lose in fuel economy and low-end torque. If you do most of your driving on the street and want to engage in drag racing, maube that's the route to go. If you actually use your MJ as a truck, and maybe even go off road -- it's probably better to leave it alone.