Can I replace a suzuki vitara 1998 v6 engine with

Correct. When you turn off the engine you lose the engine vacuum to the brake boost assist. No brakes. Can't accelerate with engine off.

Maybe this link will help
https://www.autozone.com/repairguides/Suzuki-Samurai-Sidekick-Tracker-1986-1998-Repair-Guide/HEATING-AND-AIR-CONDITIONING/Heater-Core/_/P-0900c152800883e2
A link talk about doing the work
https://www.suzuki-forums.com/suzuki-sidekick-escudo-vitara-geo-x/151097-heater-core-its-not-bad-you.html

clean clear , anon, double post, and still no car named,
nor real engine.

one of these?, sorry cant guess that or the engines.... ever.-
Here are some of Suzuki's most famous car models:

• Suzuki XL7
• Suzuki Kizashi
• Suzuki Escudo
• Suzuki SX4
• Suzuki Wagon R
• Suzuki Alto
• Suzuki Cervo
• Suzuki Cappuccino
• Suzuki Fronte
• Suzuki Grand Vitara
• Suzuki Ignis

Here are some of Suzuki's list of current models:

• Suzuki Ertiga
• Suzuki Every
• Suzuki Kizashi
• Suzuki SX4
• Suzuki Swift
• Suzuki Splash
• Suzuki Solio
• Suzuki Wagon R
• Suzuki Palette
• Suzuki MR Wagon
• Suzuki Lapin
• Suzuki Alto
• Suzuki Landy
• Suzuki APV
• Suzuki Jimny
• Suzuki Escudo
• Suzuki Carry
• Suzuki Equator

Here are some of Suzuki's list of former models:

• Suzuki XL7
• Suzuki X-90
• Suzuki Twin
• Suzuki Mighty Boy
• Suzuki Kei
• Suzuki Ignis
• Suzuki Fronte
• Suzuki Esteem/Cultus Crescent
• Suzuki Cultus
• Suzuki Cervo
• Suzuki Cappuccino
• Suzuki Aerio/Liana

free? google for it
or join a suzuki forum and ask there.
H20?
2.0L V6
google that. google the H20.
its simular to ours, we dont have the 2.0
h25
http://www.fixkick.com/engine/2.5L%202004%20Tracker/25L-2004-engine.pdf

this is free.
buy a real FSM from suzuki, thats not free.
but is near free. why must it be free?
i find my books called FSM off ebay, used, for like $25
the whole deal. and is less than floor mats.
you do get what you pay for in this world.
you need data on the H20
and its unique, EFI system. both.
we have it on Chevy Trackers and on Grandvitara's

try these guys - http://www.rebuiltautoengines.com/suzuki-vitara-used_engines.html

A typical Mazda RF Diesel Engine requires approximately 5.5litres of engine oil if the engine oil filter is replaced as well.

your catalitic converter has gone bad.

I will assume you have the same thing as in a Suzuki Grand Vitara :
N : Neutral : use this when you tow your vehicle.
4H : Use it in normal road conditions, highway, etc.
4H Lock : Use it on offroad, snow, sand, ... etc
4L Lock : Use when you are stuck on snow or sand, BE CAREFUL, this mode is only for difficult situations, do not exceed 25 MPH, and do not use it in normal conditions.
Hope this help.

It could mean that some emission-control device has failed or is due for replacment. Common items would be oxygen sensor (not too expensive) and catalytic convertor (pretty expensive).

escudo 2.0 V6, the idle is ok and the rpm quite ok, but smoke is so heavy when start in the morning, it dosent run smooth. can you help me to, i already change the spark plug but same stoyr, any solution?