Yes, once again an idle problem...
#1
Weight Watcher
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Join Date: Aug 2007
Location: France
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Yes, once again an idle problem...
Hi fellows,
on my S4 Turbo:
I had an Oxygen Sensor error code, did change the sensor.
Then wanna adjust idle for it has always been around 1200 rpm, sometimes lowers to 700 and then goes back to 1000/1200.
Today I warmed up the engine,
removed IC, fitted leds on connector and tuned TPS screw. I wish I had read the FC3S pro DMM check then...
The one led tuning is easy but within half a turn of the screw, quite not precise. If I have to tune it again I'll go for 1K ohms DMM tune.
Then settled back the IC, started the Zenki, turned the BAC adjusted screw to lower the idle... wich was impossible coz the screw was almot fully screwed!!! Unscrew means here higher RPM idle.
Then messed with the idle mixture resistor: the same! It's full anticlockwise - lean - to reach the 850 rpm not so stable! clockwise also rise RPM...
Beside the fact the idle is high the engine runs smooth and have power all the revband. Someone have an idea where to check?
And the O2 sensor still makes error code, maybe the wire is cut somewhere... is the O2 sensor used for idle? I don't think so as there's a mixture edjustable resistor...
on my S4 Turbo:
I had an Oxygen Sensor error code, did change the sensor.
Then wanna adjust idle for it has always been around 1200 rpm, sometimes lowers to 700 and then goes back to 1000/1200.
Today I warmed up the engine,
removed IC, fitted leds on connector and tuned TPS screw. I wish I had read the FC3S pro DMM check then...
The one led tuning is easy but within half a turn of the screw, quite not precise. If I have to tune it again I'll go for 1K ohms DMM tune.
Then settled back the IC, started the Zenki, turned the BAC adjusted screw to lower the idle... wich was impossible coz the screw was almot fully screwed!!! Unscrew means here higher RPM idle.
Then messed with the idle mixture resistor: the same! It's full anticlockwise - lean - to reach the 850 rpm not so stable! clockwise also rise RPM...
Beside the fact the idle is high the engine runs smooth and have power all the revband. Someone have an idea where to check?
And the O2 sensor still makes error code, maybe the wire is cut somewhere... is the O2 sensor used for idle? I don't think so as there's a mixture edjustable resistor...
#2
Takahashi Ryosuke
The O2 sensor don`t work to the idle speed......
precisly yesterday I wok in my car and see the TPS, knock my O2 sensor, maybe this be a Cut Circuit or something.
the idle speed is behind of Alternator... you can turn a little butterfly!
Is graduate the throtle
sorry x my bad english
precisly yesterday I wok in my car and see the TPS, knock my O2 sensor, maybe this be a Cut Circuit or something.
the idle speed is behind of Alternator... you can turn a little butterfly!
Is graduate the throtle
sorry x my bad english
#4
Passenger
Location: So. CaL
Posts: n/a
my FC's getting smart with me!!
i didn't want to start a new thread, and since we've got the same problem (high idle), my input isn't necesarrily "high-jacking" this thread
so my TPS is "out of spec". i adjust it to 1 ohm after driving for about an hour (it's fully warmed up)... and WALLA!! my throttle response it ALOT BETTER!! the powerband through the RPM's just feels great, HOWEVER!! my idle is now, WAY TOO HIGH @ 2500 RPM with a fully warmed up engine... and that's UNTOLERABLE for me to be idling that loud in my quiet neighborhood/police enforced town.
so i'm like.... DAMN! how can i lower the idle? turning the screw on the BAC and the boost sensor (is it safe to turn that boost sensor screw?) did very little to lower the idle, so i thought.... OH YEAHHH!! THE IDLE STOP SCREW!!
so i go ahead and loosen the idle stop screw so that it would close the throttle as much as possible:
..... and after doing so, my idle is now around the 750 RPM mark (right where i want it!!)... BUT NOW!! my throttle response feels like it did prior to adjusting the TPS... LIKE ****! what gives?! it feels like the TPS reset back to the previous setting
as a summary, with the 2500 rpm idle, i get: JOYRIDE, BACKFIRES at will , with the low "factory" 750 RPM idle, i get: sluggish performance (as if the ECU's in safe/limp mode or something [i have a Rtek 1.7 ECU]), can't backfire for **** (3" full exhaust)
things i am aware of:
¹ i never jumped the intial set coupler (i BARELY read up on that right this minute). could that contribute to this? being "electronically challenged", how do i "jump" it? i know it's that green plug by the driverside fender, on top of the leading coil... what do i do with that green plug? stick a fork in it?!
² my throttle plates CAN be dirty/sticky. with the idle stop screw not making contact with the butterfly (as pictured above), my DMM readings on the TPS are INCONSISTENT!! example: I would turn the throttle screw (screw behind alternator) until i can set it to 1 ohm. i then go to WOT (the TPS then reads inbetween 4-6 ohms), and when i let go of the throttle i expect the DMM to read back to 1 ohm, but it DRops down to about 0.6 ohms NOW.... when i tighten the idle stop screw so that it touches the butterfly, i then get CONSISTENT DMM readings. i know i DON'T NEED a new TPS because it hasn't gone "haywire" on the DMM (as per the FC3Spro.com's "warning").
³ my car can use some type of electrical inspection. the idiot lights barely work, and when the car sits under the sun for a few hours, some of the lights on the idiot cluster come on out of nowhere! it's very annoying to know that i've got electrical "gremlins" lurking.... i just want my FC to be normal damn it!!
i'll be following up on this thread and will continue to try to do as much as i possibly can to get my car running the way it's supposed to!!
so my TPS is "out of spec". i adjust it to 1 ohm after driving for about an hour (it's fully warmed up)... and WALLA!! my throttle response it ALOT BETTER!! the powerband through the RPM's just feels great, HOWEVER!! my idle is now, WAY TOO HIGH @ 2500 RPM with a fully warmed up engine... and that's UNTOLERABLE for me to be idling that loud in my quiet neighborhood/police enforced town.
so i'm like.... DAMN! how can i lower the idle? turning the screw on the BAC and the boost sensor (is it safe to turn that boost sensor screw?) did very little to lower the idle, so i thought.... OH YEAHHH!! THE IDLE STOP SCREW!!
so i go ahead and loosen the idle stop screw so that it would close the throttle as much as possible:
..... and after doing so, my idle is now around the 750 RPM mark (right where i want it!!)... BUT NOW!! my throttle response feels like it did prior to adjusting the TPS... LIKE ****! what gives?! it feels like the TPS reset back to the previous setting
as a summary, with the 2500 rpm idle, i get: JOYRIDE, BACKFIRES at will , with the low "factory" 750 RPM idle, i get: sluggish performance (as if the ECU's in safe/limp mode or something [i have a Rtek 1.7 ECU]), can't backfire for **** (3" full exhaust)
things i am aware of:
¹ i never jumped the intial set coupler (i BARELY read up on that right this minute). could that contribute to this? being "electronically challenged", how do i "jump" it? i know it's that green plug by the driverside fender, on top of the leading coil... what do i do with that green plug? stick a fork in it?!
² my throttle plates CAN be dirty/sticky. with the idle stop screw not making contact with the butterfly (as pictured above), my DMM readings on the TPS are INCONSISTENT!! example: I would turn the throttle screw (screw behind alternator) until i can set it to 1 ohm. i then go to WOT (the TPS then reads inbetween 4-6 ohms), and when i let go of the throttle i expect the DMM to read back to 1 ohm, but it DRops down to about 0.6 ohms NOW.... when i tighten the idle stop screw so that it touches the butterfly, i then get CONSISTENT DMM readings. i know i DON'T NEED a new TPS because it hasn't gone "haywire" on the DMM (as per the FC3Spro.com's "warning").
³ my car can use some type of electrical inspection. the idiot lights barely work, and when the car sits under the sun for a few hours, some of the lights on the idiot cluster come on out of nowhere! it's very annoying to know that i've got electrical "gremlins" lurking.... i just want my FC to be normal damn it!!
i'll be following up on this thread and will continue to try to do as much as i possibly can to get my car running the way it's supposed to!!
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