b16a1 fluctuating idle 200 rpm . HELP
 

my idle fluctuates 200/300 RPM
COLD don't fluctuates
hot engine fluctuates 30 seconds after starts running ( the first 30s when is hot don't fluctuates )

I've done:

-IACV-
clean 2 times, i close the IACV and engine still fluctuates

-FITV-
clean 2 times, i close the FITV and engine still fluctuates

-vacuum system-
the vacuum system was verified with proper gun, and check the tubes, tube are like new
check with proper smoke equipment (smoke will emerge on leaks)
test it with carburettor cleaner

-TPS-
tested 3 - all tuned to 0.45v open , 4.55V closed

-TB-
clean and tested 2

-IAT-
temperature sensor admission was clean

-Bleeding Air In Cooling System-
done several times

-ECU-
tested 2 stock ECUs

-valve lash-
in 0.15mm
ex 0.20mm

-ignition timing-
15 deg.

-engine timing-
its ok ( set properly )

-cams are proper in alignment

-compression check-
cylinder 4 - 11.5
cylinder 3 - 12.5
cylinder 2 - 11.5
cylinder 1 - 12.5

-spark plug wires-
3 sets tested (2 used, 1 new NGK)

-spark plug-
tested 2 sets (NGK BKR6E-11 || 5304 Denso Iridium IK20)


TESTS with STRANGE results

if i unplug the TPS idle stops fluctuates
if i unplug a spak cable (any one) and plug again idle stops fluctuates


what more can i do ?





i decide to change my ecu pw0-x00(obd0) to obd1
so, i made this changes.

-b18c4 exhaust manifold
-p28 ecu (chipped with p30 map)
-td-86u dizzy with obd1 plugs
-4 wires o2 sensor

and now with o2 sensor enable i dont have fluctuating idle

THANKS TO ALL !!! for helping

Re: b16a1 fluctuating idle 200 rpm . HELP
 

did this today, and didn't solve my idle problem :(

-valve lash
in 0.15mm
ex 0.20mm

-ignition timing
15 deg.

-engine timing
its ok ( set properly )

-cams are proper alignment

-compression check
cylinder 4 - 11.5
cylinder 3 - 12.5
cylinder 2 - 11.5
cylinder 1 - 12.5

Re: b16a1 fluctuating idle 200 rpm . HELP
 

why 15 degrees ignition timing?
it should be same as your engine timing
which should be 16.5

Re: b16a1 fluctuating idle 200 rpm . HELP
 

have you checked your fpr they do go out sometimes

check coil it gets damaged by heat and looses charge sometimes and then slowly dies and wont start
one sure sign is rpm drop at the traffic light

Re: b16a1 fluctuating idle 200 rpm . HELP
 

what is FPR ?

my engine manual / service says the ignition timing is 15 +-2 ( 13 , 14 ,15, 16 , 17)

tried on 16º .. didnt solve idle problem

Re: b16a1 fluctuating idle 200 rpm . HELP
 

the td22u distributor is one thing i couldn't test, because i have no access to other one :(

Re: b16a1 fluctuating idle 200 rpm . HELP
 

test the coil and ignitor

u have a chipped ecu or stock?

its idling at 1100 rpm when it should be at 750-850rpm
your coolant temp looks like only1/4 if that's as high as it goes that means your thermostat is stuck open(failsafe)
which means the engine is not at full operating temp

high idle can also mean vacuum leaks and they are sometimes not very easy to find

Re: b16a1 fluctuating idle 200 rpm . HELP
 

the vacuum system was verified with proper gun, and check the tubes, tube are like new
check with proper smoke equipment (smoke will emerge on leaks)
test it with carburettor cleaner

i have no vacuum leaks

sorry about the coolant ( to use s2000 cluster it needs a converter for speed ans coolant, i sent the converter to tuned the speed to have the REAL GPS speed, so the coolant is working good, but without the converter the coolant dont work )

Re: b16a1 fluctuating idle 200 rpm . HELP
 

i made other approach...

i decide to disable the first oxygen sensor on the ECU ( on BRE )

idle problem solve, with 1st o2 sensor DISABLE and 2nd O2 ENABLE

(i think thats why the idle start after 30s, because is when ECU starts making adjusts on AFR)

do i have the 1st o2 sensor defective ?
my ECU gives me NO errors

is normal to have a defective sensor with no ECU error ?
could be a exhaust manifold leak ? a leak on 1st o2 sensor hole ?

just cleaning solves the problem ?

https://dl.dropboxusercontent.com/u/...t_manifold.jpg

unless the magic idle adjustment fairy came and turned the idle adjustment screw while you were sleeping, ignore what this guy said and fix the actual problem instead of creating another one

Re: b16a1 fluctuating idle 200 rpm . HELP
 

@mfreeman

isnt the idle screw, that was the first thing i did, and i tried 2 TB, so 2 screw ;)

Re: b16a1 fluctuating idle 200 rpm . HELP
 

do you think is the 1st o2 sensor of a 1 , 4 injector ?

i would replace the upstream oxygen sensor with a Denso ... it helps to know what your exact year, make, and model

after replacing the oxygen sensor you will need to reset your base idle if you fiddled with the idle adjustment screw already

Re: b16a1 fluctuating idle 200 rpm . HELP
 

my car is CRX EE8 EDM 1991 b16a1

Re: b16a1 fluctuating idle 200 rpm . HELP
 

found out that the second o2 sensor had the wire cut

replace the second o2 sensor (for a used one), and didnt solve my problem

Re: b16a1 fluctuating idle 200 rpm . HELP
 

i decide to change my ecu pw0-x00(obd0) to obd1
so, i made this changes.

-b18c4 exhaust manifold
-p28 ecu (chipped with p30 map)
-td-86u dizzy with obd1 plugs
-4 wires o2 sensor

and now with o2 sensor enable i dont have fluctuating idle

THANKS TO ALL !!! for helping