AFRs seem bass-ackwards on a stock NA S4.
#1
Hopefully this is the right section to post this.
I've got an NA S4 that I'm fairly new to (it's my first rotary). It came with an AEM wideband O2 and gauge, and they've been working quite well so far (AFRs make sense, in that when I'm cruising, it's 14.7, and when I'm on it, it's closer to 12).
Now, when I'm cruising, the AFRs will stay quite rich 12:1, then when I am at about 1/4~1/3 throttle, they go to 14.7 (as if I'm cruising, when I'm really lightly accelerating), then go back down towards 12:1 when I'm really on it. Driveability seems the same, as does idle.
Is there a common flaw that could be causing this? Is my TPS a likely culprit? It almost seems as if the ECU doesn't know when I'm at part throttle/cruise, and is confusing it with full throttle. What should I check?
Thanks!
I've got an NA S4 that I'm fairly new to (it's my first rotary). It came with an AEM wideband O2 and gauge, and they've been working quite well so far (AFRs make sense, in that when I'm cruising, it's 14.7, and when I'm on it, it's closer to 12).
Now, when I'm cruising, the AFRs will stay quite rich 12:1, then when I am at about 1/4~1/3 throttle, they go to 14.7 (as if I'm cruising, when I'm really lightly accelerating), then go back down towards 12:1 when I'm really on it. Driveability seems the same, as does idle.
Is there a common flaw that could be causing this? Is my TPS a likely culprit? It almost seems as if the ECU doesn't know when I'm at part throttle/cruise, and is confusing it with full throttle. What should I check?
Thanks!
#3
there is also that switch in the bottom of the radiator. its function is basically to turn on closed loop, and the emissions system. the switch doesnt usually go bad, the wires run under the battery tray and usually get kinked/bent twisted
another thing to look at might be the stock o2 sensor, if you still have it
another thing to look at might be the stock o2 sensor, if you still have it
#5
#6
Originally Posted by ilia' post='875422' date='Jun 18 2007, 09:28 AM
Hmm, I'll definitely check that out. Do you know what it's called? You don't have a picture of it, by chance, do you?
easy to find, its on the bottom tank of the radiator, left side, BIG bolt lookin thing with 2 wires
#8
Originally Posted by Henrik' post='875505' date='Jun 18 2007, 08:16 PM
Its not the sensor on the rad - if it was, it wouldn't go closed loop at higher throttle. Check
your TPS.
-Henrik
OK, so my initial hunch might be right... It was really stumping me how it's still entering closed loop mode at all, because I had assumed that a bad O2 or this other sensor would make it go to a default map with no ability to do closed loop.
I'll check TPS tomorrow, and see how it is.
Thanks!
#9
Update:
Disconnected the TPS to check it's readings, reconnected it, now the car really doesn't do anything right.
Runs halfway OK until 1/3-1/2 throttle. At 1/2 throttle, air:fuel goes to 10.0:1, and the car bucks hard.
The TPS was indeed out of adjustment, and after the car started doing this, I adjusted it so that the car showed a reading of 1 volt. That didn't really help anything. Any ideas?
Disconnected the TPS to check it's readings, reconnected it, now the car really doesn't do anything right.
Runs halfway OK until 1/3-1/2 throttle. At 1/2 throttle, air:fuel goes to 10.0:1, and the car bucks hard.
The TPS was indeed out of adjustment, and after the car started doing this, I adjusted it so that the car showed a reading of 1 volt. That didn't really help anything. Any ideas?
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