RX300 2003 1MZ V6 engine engine hunting when hot n dies off

at what RPM?,sure the 2wd has no tachometer,

Sidekick, with what engine? sure 5speed and 2wd,
but what engine.?
in 1995 they (last year this) 2 engines
the 8v and 16valve,
both, night and day different, EFI.
TBI and MPI injected, 8v is black top, 16v says 16 valves on top.
but both engines, will fail ISC controls like that if there are problems.(idle speed controls)
the surging (hunting) is one of 2 things.

1. (too lean, or air leaks)
2. or ISC lost control)
   

the ECU on the car will in fact hunt the ISC if it can not attain
800 RPM hot IDLE, that is its JOB, to do that, endlessly.
in fact 200 times a second.!
but is not working. (this control, its out of control for sure)
to find this can be easy or hard.? (luck and true causes)
depends on true cause.
I cant do both engines here, be like 10 pages.
The 8v engine races with all air leaks. and hunts. (races)
the 16v goes lean with all air leaks, (air density system is unique)
and goes slower, RPM and may hunt. no RPM stated so cant wax smarter...sorry.

so its a dirty ISC? cant close fully, ? clean it? first.
the 8v has air leaks. caused by vast reasons.
cracked hoses. leaking diaphragms, even the brake booster can leak. lots of leakage patch possible
or some one fiddled the idle air bleed screw making it fail.
try closing that valve (screw) turn it CW directly clock wise.

this page covers both systems.

http://www.fixkick.com/fresh-air/idle-air-supply.html


this ISC cleans just like the EGR that leaks.
egr leaking cause, low RPm and it too, can make the ISC go nuts.
so, but no RPM stated. so.....
eg: hunting from 1000 to 1500RPM
or hunting from 500 to 700 rpm?

i pinch all hoses first.
if RPM drops the hose is cracked or the other end is leaking air.
every 50k miles?

http://www.fixkick.com/sensors/cleaning-egr-isc/double-trouble1w.JPG

does RPM go below 800 RPM HOT engine?
yes ./no
this a is key factor.

HOt engine, or cold engine or both???????????????
Gas or Diesel? what engine>? 4 speed A/T right?
first off the CEL only glows for smog fails, many other DTC errors
all important , only show up on a real scan tool. even a $9 tool this old car.
is it the tranny or the engine hunting, that takes, skill to know.
any mech , can tell you ,easy.
ENGINE:
does the engine run prefect , get to 180F + temp and hold?
does the enigine hold 800 RPM steady hot idle in park.
then select Drive, foot on brake pedal and still hold this normal idle spee?d. , yes, then good.
this hunting, i cant understand that.
does it upshift to all gears, correctly?
and down shift.?
and does it not hold one gear. at cruise? flat ground.
does it not down shift with fast deep throttle.
does not down shift on hills.
exactly when does it hunt, you doing what?, in drive, im guess.
tell driving conditions, and right foot actions.
steady foot.
flat ground,
accel?
decel.
hills.
coasting?

my FSM has over 50 A/T symtoms. the A/T is complex.
a driver (mech) will do many tests driving to see what works and what dont.. (both)

BTW2: i never pay any attention to any CEL lamp, I SCAN all cars.
ALL.
The newer the car , the more DTC's , the key is to NOT MISS THEM.
and win.

Your A/T may be electronically shifted, and if yes, it's got a TCM
(either the TCM box or is part of the PCM )
either why. ,make sure the TCM never sees errors, ever.
there are many inputs to any TCM and all must be correct or the tranny will shift wrong, or go to limphome mode.

what tranny,????
here is the wiki.
Transmissions for the Ram

• A500/42RH-RE lower geared light duty applications found behind the 3.9 L V6,
• A518/46RH-RE for more heavy duty applications found behind the 5.2 L and 5.9 L V8 engines.
• A618/47RH-RE for heavy duty use behind the V10 gasoline and Cummins diesel engines. The 47RH was used in 1994 and 1995 model years, while the 47RE was used from 1996 through 2002.

NV3500 and up are manual trans,
so by wiki I see all 3 are electric, SCAN it now , with a full scan tool.



each tanny ending in "E" is a TCM shifted "E"lectronic shifted trans.
so post what you have, as i can not guess.

my guess is 46RH

fuel issue possibly MAP sensor or tps sensor? any check engine light?? transmission not shifting??

sounds like your automatic transmission is stuffed, take it to a mechanic for a second opinion but it seems to me like you'll need to either rebuild or replace the transmission

DId the Check Engine light ever come on?? Normally with such a major problem the check engine light should of activated in which case you can take it to a Autozone or most auto parts stores adn they can plug a Code reader into your system download the codes/messages and it should pinpoint or at least point you in the correct direction as to what is causing your issues.
I have had to do that a couple times with my 2005 Chrysler T&C due to a O2 Issue, and a Catalytic convertor issue.

this sounds like an external voltage regulator issue..when it gets hot or shuts itself off the battery is whats running the vehicle..until the operating voltage drops below minimal.. then it all stops..get the charging system checked at a parts store.. they do it for free..

check your cooling system & ck for vacuum leaks. Try to get an emissions test or PC scan to get live readings of the emissions

Sounds like a bad/large vacume leak.

check for a vaccuum leak this is where i would start if it rolled into my shop. possibly a PCV valve sticking or a hole in the hose, this hose should run from the valve cover, or crank case and then to the intake, or carb.

i had the same problem on my 95 pajero 3500 andafter all my troubles my car produced an occasional airfilter blow back from running on gas before it finally would'nt run my problem turned out to be my crankshaft sensor was failing then died.