Idle issue

[JMT]

I have a Sidekick Sport 1.8 Standard. Recently the engine idle hasn't been holding and not all the time. Sometimes the idel will drop 200 rpms for a while and then go back to normal. This can last a while and it might not happen at all. Any suggestions, thanks

[jtgh]

can be 3 things, and are random.

EGR sticking open. main valve. (yours is stepper motor driven and is stronger)
but can be cleaned. (carb cleaner, or TB cleaner, or FI induction cleaner.......)

TPS idle switch bad ( or out of calibration) ,mine just failed last night. (1.8 is diffr read on)
last:
ISC dirty or bad.
dies at every stop sign.


the 1.8L does not have an idle switch.
it only has a 3 pin TPS throttle pot.

connect VM to pins2 gray and gray/yell pin 1 and set tps for .5v. (key on , not started and must be connected and back probed !!)

thats 0.5v or 1/2 volt exactly.

then monitor this pin with VM (volt meter) and blip throttle.
it must return to .0.5v each time. or it is bad.
my guess is if it sticks above 1v its bad on any BLIP.

BLIP ,flip, or bump throttle bell crank on side of TB. (throttle body.)


TPS has screws and slots , it is ADJUSTABLE and you set it to 0.5v for idle, KEY ON, not running.

i will see if i can find full procedure later

cheers.

[jtgh]

excerpted from pages.....

the procedure fails to state KEY position.

key on ,no start should work best.
and you must back probe connector at TPS because the ECU powers the ECU.
no connection equals no power to TPS.

I use leather sewing needles for back probing , when i dont have my fancy dancy backprobing , probes at work ( Pomona leads)

1 of many you can use.

6262-2


or
here

Pomona 6530A > Deluxe Automotive Test Lead Kit 6530A Pomona Test Equipment
a full set.


blow up of pins.
Fluke- Pomona Back Probe Set of four FREE S/H - eBay (item 370217981436 end time Jun-26-09 21:40:24 PDT)

[noisey jack]

Do you have air conditiouner ?

[jtgh]

thats correct.

if ECU see A/C switch ON, for any reason, idle is raised.
same with P/S over load switch.

200 rpm is not a symptom of that. 1000 is.

The 1.8L has a hard to clean EGR (but has a 1 part EGR system) no VSVS, tubes and other junk, ECU is vastly smarter and runs EGR valve all by its self.
and NO STinking MOD VALVE.
I suspect 1.8L will allow exhaust changes. to a greater degree too.

if the tps switch ( and will be intermittant at first) fails, the ecu is never signaled
that you are idling ,
when that happens, the ISC is shut down.
the ecu , thinks you are cruising.
so the only air you get is leakage around the all most closed, throttle plate.


the 1.8L has a electric IAC/isc valve , this valve can stick closed.
it is the primary source of air at idle , HOT.

if you think compressor is overloading motor. just drop the belt.
why guess. drop it.
make sure you dont have a serpentine belt that runs them all.
most kicks have PS/AC belt. is see same on 1.8L pl, just diff. routing.


Id have the hear motor , and listen to bearing with my stethoscope.
ive see bad alterator bearings do , amazing things.

one has to keep an open mind, but hands on , there is no subs.

cheers.

[JMT]

Here are some observations regarding my idle problem -

1. Engine cold - after starting rpm is slightly elevated as in winter time and slowly drops to normal idle.

2. For a period of time the engine idles properly and can use the a/c without having an impact on the engine.

3. For no particular reason other than possibly engine has warmed up the idle will drop when vehicle not moving and will drastically drop if a/c turned on almost causing vehicle to stall.

4. BUT, the #3 issue doesn't always happen and I can turn the vehicle off and sometimes a few minutes later start again and the idle is fine for period of time.

It was suggested that I just replace the EGR valve??

Haven't tried suggestions of jtgh of june 22 yet hopefully tomorrow

[jtgh]

its mostlikly
TPS , bad spot in end of range , glitching high, wrongly.
ISC sticking.
EGR leaking when should be closed at idle.

I had bad tps and sticking EGR.
cleaned my EGR, and replaced my tps.

it is not easy to find which it is.
but cleaning the EGR good and the ISC , will leave a
TPS , naked in the flood...

[jimllfixowt]

That sounds like bad spark plugs or cam chain sensor

[jtgh]

1.8 , new spark plugs.
new fuel filter and air filter.
does CEL lamp go out , after running, if not then pull the DTC trouble codes with any scan tool.

is cam chain quiet , or is it trashing away up front, do not Ignore chain noise on any chain cam motor.


random idle drop.

EGR leaking , just clean it so it closes everthing you release the diaphram.
(in hand)

ISC remove it , leave hoses in place, and clean it too .

use carb cleaner and plastic stick to gently tickle it while cleaning it.

The car has TSP , this device has a TPS switch ,
if the switch is bad or no calibrated, the switch may fail to close.
if at any time (any car with one) fails to close this switch the ECU will never enter IDLE control mode, or if it fails to close at every stop sign or traffic light (RED)
then the ECu will no enter IDLE control mode.

when this happens all regulation of idle , ends and idle becomes random.

[jtgh]

one thing nice on 1.8L the tps can be had vastly cheaper.
its only got 3 pins and fits Esteems too. and other cars.

saw one for $33 . ( the 1.6L is $125 to $300 )


the Idle on this car
holds a constant idle , regardless of the following loads (as applicable)

FAN on
Defrost on
From Park/Neutrral into DRIVE (A/t) shift change.
Head lights on. all above hold idle at 800 solid. (ISC action)

that is the test , right out of FSm, the acid test. if that dont work somethings wrong.

in addition
it raise idle when A/C is switched on.
or
you over load P/S , eg; crank wheel to the stops. (P/S olver load switch does that)