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Forum nameTurbo/Nitrous Tech
Topic subjectS-AFC sensor check
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=32744
32744, S-AFC sensor check
Posted by Dave_FL, Oct-14-02 06:59 AM
What do you guys get at idle for the throttle sensor and what do you get when its floored? I am curious to see if my TPS is messed up.
32745, RE: S-AFC sensor check
Posted by fabry827, Oct-14-02 07:12 AM
I get 0 @ idle and 100 @ full throttle.
32746, RE: S-AFC sensor check
Posted by mcgyvr, Oct-14-02 08:09 AM
I get .685-.715 at idle and approx 3.85 at full throttle

did you do the blue wire mod??
I only get may .83 at WOT on IN-2
only once in a while it is .97
maybe im just not reaching WOT but the gas is all the way to the floor.
I think the s-afc induces too much resistance into the circuit
32747, RE: S-AFC sensor check
Posted by BoostedGS, Oct-14-02 08:22 AM
Hey Dave. I had the same problem that I think you're having. My TPS was all messed up, it read like 35% at idle, and 77% at WOT. I replaced my TPS ($55 at Autozone) and it immediately read 0% at idle, but still only read 77% at WOT.

What you'll need to do is put the key in the ON position, but don't start the car. Then floor the gas and hold it and you'll see your throttle position slowly rise until you get to 100%. After that it reads correctly.
32748, RE: S-AFC sensor check
Posted by Dave_FL, Oct-14-02 09:15 AM
My throttle percentage is fine. I am just wondering if the TPS is workign right because I have a lumpy idle and I think it is a sensor. After my first rebuild I suspected the timing was off a hair but it isnt. It has to be a sensor and I think it may be the TPS. And it only started after my first rebuild and now after the new set of pistons went in it still idles weird. Its almost like cams but a little faster liek a rotory engine. I think one of the sensors after my first rebuild went bad.
32749, RE: S-AFC sensor check
Posted by MrSlick, Oct-14-02 09:39 AM
What do you have for the In and OUT sensor settings?

If you have them both on 7 try setting them to 6. I had a similar problem to you wiht mine set to 7.... went away when I went to 6.
32750, RE: S-AFC sensor check
Posted by Dave_FL, Oct-14-02 02:17 PM
It did it beforte I had the S-afc hooked up. I get only .49 at idle and only 3.6 at WOT. I guess my TPS sensor is dieing?
32751, RE: S-AFC sensor check
Posted by mcgyvr, Oct-15-02 01:09 AM
You TPS is fine, it can be anywhere from like .35 to 1.0 at idle
You can do the TPS modification to bump it back up to like .75 at idle

The TPS is a variable resistor and it wont just slowly die.
It just needs adjustment
You just drill out the metal sleeve that the two torx screws go into and move the TPS around checking voltage until it gets where you want it

closest to 1.0v as possible at idle
and closest to 4.0v at WOT

I think my settings are perfect .75 idle 3.85 WOT
32752, RE: S-AFC sensor check
Posted by Dave_FL, Oct-15-02 06:13 AM
So I guess that isnt what is causing my lumpy idle. Maybe its the CAM sensor or crank sensor.
32753, RE: S-AFC sensor check
Posted by mcgyvr, Oct-15-02 07:31 AM
I would bump the voltage up like i said in the post above, maybe the voltage is low enough to cause problems in your idle but not bad enough to be considered out of range/broken.

Try the TPS mod it takes a couple minutes and if after you reset the ECU its still a problem then I would check your other sensors or even try cleaning out the TB maybe its super dirty causing problems

Im getting a crappy idle now cause the CEL is on for the EGR system not detecting adaquate EGR flow.
You still got the EGR system
32754, RE: S-AFC sensor check
Posted by Dave_FL, Oct-15-02 02:02 PM
I am going to do that TPS thing and see what happens. It did it before I had the egr block off on the car and after it too.