Fast Idle Cam, high idle help (coolant hose removed)
08-23-13, 01:44 AM
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Fast Idle Cam, high idle help (coolant hose removed)
I had a high idle and was trying to figure it out. I asked "arghx" for help and he was nice enough to do so so. Here is our convo, maybe it can help someone else in the future.
You with an assistant get your commander out and go to etc--> sensor/switch check. Look at VTA1 and VTA2, the throttle position sensor voltages.
With the engine cold, take the fast idle cam and rotate it around with your finger. If the throttle voltages drop (more than like .01, basically noise or lash in the sensor) then your fast idle cam is affecting your cold idle. Do the same with the engine warm, and you'll see if it's affecting your warm idle.
What I do, if aesthetics aren't a big issue, is ziptie the fast idle cam away so that it can't affect the idle. That's on engines with the coolant hose removed.
I wouldn't mind using a ziptie to move the fast idle cam away Im just not quite sure what you mean by that. Here is a pic of the fast idle cam, do i ziptie it and pull it to the right or to the left?
https://www.rx7club.com/attachments/...eded-fd_tb-jpg
Thanks for all you help. Sam
In that pic you'll see that the fast idle cam rests on the wax rod. As the wax rod expands from hot coolant (when the hose is hooked up), it makes the cam rotate away. So you want to rotate it away and secure it with a ziptie, just to make sure it's not interfering with the idle. Or put the hose back on.
Ok I just took a look at it and yea I will pull it back and ziptie it and I'll let you know what happens. Fixing something else on my car so can't start it for a few days.
TO BE CONTINUED
Originally Posted by arghx
Originally Posted by supak111
Originally Posted by arghx
Originally Posted by supak111
Hey arghx I just read your "make your PFC basemap safer" AMAZING READ, thanks for posting it.
As you clearly know your stuff I was wondering if you could answer a few questions I had about my high sticky idle. First I had a lumpy idle but after reading your above post I did some tweaking and the car idles ok, doesn't surge. Thanks
But now I get a sticky high idle when the car is warm. It idles lower when the car is cold. Cold still idles higher then PFC settings but it gets even higher when it warms up. PFC idle set at 1000rpm, cold idle is 1300/1400rpm, warm idle is 1700/1800rpm.
Now I read what you said usually causes sticky high idle. My FD doesn't have coolant running through it so can the "fast idle cam" and themomax still cause high idle?
Also I notice that my fast idle cam is screwed all the way in pushing really hard on the thermomax, I just wasn't sure if it mattered since I have no coolent in there
As you clearly know your stuff I was wondering if you could answer a few questions I had about my high sticky idle. First I had a lumpy idle but after reading your above post I did some tweaking and the car idles ok, doesn't surge. Thanks
But now I get a sticky high idle when the car is warm. It idles lower when the car is cold. Cold still idles higher then PFC settings but it gets even higher when it warms up. PFC idle set at 1000rpm, cold idle is 1300/1400rpm, warm idle is 1700/1800rpm.
Now I read what you said usually causes sticky high idle. My FD doesn't have coolant running through it so can the "fast idle cam" and themomax still cause high idle?
Also I notice that my fast idle cam is screwed all the way in pushing really hard on the thermomax, I just wasn't sure if it mattered since I have no coolent in there
With the engine cold, take the fast idle cam and rotate it around with your finger. If the throttle voltages drop (more than like .01, basically noise or lash in the sensor) then your fast idle cam is affecting your cold idle. Do the same with the engine warm, and you'll see if it's affecting your warm idle.
What I do, if aesthetics aren't a big issue, is ziptie the fast idle cam away so that it can't affect the idle. That's on engines with the coolant hose removed.
I wouldn't mind using a ziptie to move the fast idle cam away Im just not quite sure what you mean by that. Here is a pic of the fast idle cam, do i ziptie it and pull it to the right or to the left?
https://www.rx7club.com/attachments/...eded-fd_tb-jpg
Thanks for all you help. Sam
In that pic you'll see that the fast idle cam rests on the wax rod. As the wax rod expands from hot coolant (when the hose is hooked up), it makes the cam rotate away. So you want to rotate it away and secure it with a ziptie, just to make sure it's not interfering with the idle. Or put the hose back on.
TO BE CONTINUED
08-23-13, 11:23 AM
#3
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If you're removing that fast idle cam, do it the right way and remove the whole assembly from the throttle body. A few screws and you take the whole thing off.
A zip tie will get you over the hump but, in theory, you can have it bind up or have other weirdness. It's best to totally remove it.
Actually, a better method to temporarily disable it is to put something in between the adjust screw and the thermowax rod. A cap type nut works awesome.
Dale
A zip tie will get you over the hump but, in theory, you can have it bind up or have other weirdness. It's best to totally remove it.
Actually, a better method to temporarily disable it is to put something in between the adjust screw and the thermowax rod. A cap type nut works awesome.
Dale
08-23-13, 02:20 PM
#5
I just did this to my throttle body... you can just remove it completely with no possible leak. You'll need to remove the TPS assembly to slide the Fast Idle Cam assembly off. I also removed the small shaft that's pressed in the side. Also, this is a good chance to change the TPS bolts to allen head since the stock phillips bolts are a bitch to take off and usually get stripped.
08-23-13, 03:19 PM
#6
I just did this to my throttle body... you can just remove it completely with no possible leak. You'll need to remove the TPS assembly to slide the Fast Idle Cam assembly off. I also removed the small shaft that's pressed in the side. Also, this is a good chance to change the TPS bolts to allen head since the stock phillips bolts are a bitch to take off and usually get stripped.
Thanks,
Ryan
08-29-13, 03:39 PM
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Ok guys I finally figured out my lumpy idle and high idle. First off I replaced the alternator, my alternator was going out. I started looking at the Volt gauge on my PFC and the alternator would charge one minute be at 14.1-14.5volts, then bit later not charging and the voltage would be as low as 11.5v. Good working charging alternator should be above 14v when car is ON and alternator spinning. I replaced it and now its always at 14.1-14.5v. PS this was also causing my battery and ABS lights to come ON and OFF (see my other thread)
After the alternator all I did was unscrew that throttle adjustment screw all the way out so that the butterflies close all the way and now my car idle AMAZING. Now my idle control valve & PFC do the idle adjustments.
I can now put the idle at 800RPM and the engine still runs super smooth even that low. I did not mess with the fast idle cam, mine at least wasn't the problem. I personally can't believe that I could get it to idle this smooth seeing how EVERYTHING unnecessary was removed from my engine (all vacuum lines, no coolant lines, no solenoids...) I'm :-)
So a quick recap, make sure that on your PFC: O2 sensor is OFF, Idle Control is ON, and that fuel cut is around 200rpm higher then what you set your idle at. (this worked for me)
After the alternator all I did was unscrew that throttle adjustment screw all the way out so that the butterflies close all the way and now my car idle AMAZING. Now my idle control valve & PFC do the idle adjustments.
I can now put the idle at 800RPM and the engine still runs super smooth even that low. I did not mess with the fast idle cam, mine at least wasn't the problem. I personally can't believe that I could get it to idle this smooth seeing how EVERYTHING unnecessary was removed from my engine (all vacuum lines, no coolant lines, no solenoids...) I'm :-)
So a quick recap, make sure that on your PFC: O2 sensor is OFF, Idle Control is ON, and that fuel cut is around 200rpm higher then what you set your idle at. (this worked for me)
Last edited by supak111; 08-29-13 at 03:43 PM.
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