Can a CPS output be dependent on temperature?
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jetjock said:
Ah, I see that now. Makes sense.
jetjock said:
Well, I covered the intake with a plastic bag, and at idle, it stayed at 4.9 (it says 4.9 when the engine is not running, btw)...0.00V as soon as I raise the RPMs, even slightly. Then once I let it return to idle, it will return to 4.9 after a couple of seconds. Does this mean it is running in open loop? Wouldn't it throw some kind of code?
jetjock said:That it doesn't, along with the normal Vf you reported when T isn't grounded, implies not only that the sensor is working but the misfire isn't mixture related. Hard to tell from here though. I dunno about you but I'm going to sleep on it
Well, when I first started this test (Vf, T not grounded), it showed around ~2.2, and after i increased the RPMs, it went to ~3.5 and then stayed there, even when I let it go back to idle.
Not sure it that is normal.
A lack of fuel pressure will make you go lean, but you would probably notice a lack of power before you hit a misfire. As JJ already indicated.
1) Forget the 5 volts on Vf at idle. It's not relevant if T is grounded.
2) Yes, 0 volts off idle means open loop. If the O2 sensor is good the engine is lean. If it's bad the engine is slightly rich because the ECU will ignore the bad sensor and default to slightly rich when it sets the code. You won't get the code right away because the only codes associated with mixture are two-trip O2 codes. That you haven't gotten any even though you've cycled the ignition key several times is further indication your sensor is working.
3) Yes, a Vf of 2.2-3.5 is normal during steady state conditions (idle or cruise). The "problem" is you wouldn't be getting that if the O2 sensor wasn't working and the engine was in open loop.
Centech? Ugh. Still, it should be able to see O2 sensor cross counts at idle when looking at OX or slightly off idle on Vf because they happen so slowly. An led and resistor connected to Vf should do the same. Let us know what Aaron finds but I'll be surprised if your misfire is mixture related.
2) Yes, 0 volts off idle means open loop. If the O2 sensor is good the engine is lean. If it's bad the engine is slightly rich because the ECU will ignore the bad sensor and default to slightly rich when it sets the code. You won't get the code right away because the only codes associated with mixture are two-trip O2 codes. That you haven't gotten any even though you've cycled the ignition key several times is further indication your sensor is working.
3) Yes, a Vf of 2.2-3.5 is normal during steady state conditions (idle or cruise). The "problem" is you wouldn't be getting that if the O2 sensor wasn't working and the engine was in open loop.
Centech? Ugh. Still, it should be able to see O2 sensor cross counts at idle when looking at OX or slightly off idle on Vf because they happen so slowly. An led and resistor connected to Vf should do the same. Let us know what Aaron finds but I'll be surprised if your misfire is mixture related.
Damn! I am asleep at the wheel on this one, and there goes my rep! :cry:
Okay, its not running rich, and pulling the booster hose will not help anything. Disregard my post, it is worthless advice.
Okay, its not running rich, and pulling the booster hose will not help anything. Disregard my post, it is worthless advice.
jetjock said:I was referring to your acceptance of 3p's suggestion. He's confused. Since I've never seen him wrong about anything before he's entitled once in a while. We all are. That said you should answer the man's question about your meter. He's trying to help you, as am I. (God only knows why
Centech, yuk! I got one of those as a freebie at a conference I went to. I compared it to my Fluke and it was way off on current measurements. Its probably okay for voltage though. In any case, its good enough for seeing cross counts.
Its an interesting problem.
The Vf shows all is normal and the MIL light is off after multiple trips, yet the system is apparently not cross-counting and is hard over lean. Something doesn't add up! Keep us posted on what Aaron finds out.
Its an interesting problem.
The Vf shows all is normal and the MIL light is off after multiple trips, yet the system is apparently not cross-counting and is hard over lean. Something doesn't add up! Keep us posted on what Aaron finds out.
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Lol, I can assure you your rep is safe my friend...your record stands on it's own merit. Vf is not often used in other than the normal way. I had to look it up myself to be sure I was getting it right.
Maybe I have my meter set wrong when I am testing for cross-counts? I have the dial set to 200, the decimal looks like this: 0.00...is that right?
I am thinking this could be a wiring problem? I really want to get this new problem fixed as well as the misfire problem.
Also, something interesting I noted, was that while driving the car last night (it was a cool night, ~50F) the car barely was misfiring at all, it was very slight...but it seems like when it is hot out 75+, it misfires much worse. This leads me to believe that the AFM may have something to do with it?
Also, the trip to Aaron's shop has been postponed, because it will be raining all evening going in to tomorrow, and I don't want to drive my Supra in the rain, in rush-hour LA traffic...lol.
I am thinking this could be a wiring problem? I really want to get this new problem fixed as well as the misfire problem.
Also, something interesting I noted, was that while driving the car last night (it was a cool night, ~50F) the car barely was misfiring at all, it was very slight...but it seems like when it is hot out 75+, it misfires much worse. This leads me to believe that the AFM may have something to do with it?
Also, the trip to Aaron's shop has been postponed, because it will be raining all evening going in to tomorrow, and I don't want to drive my Supra in the rain, in rush-hour LA traffic...lol.
Well, I decided to go to Aaron's anyway...
You guys are going to hate me, but Jose checked my timing, and it was WAY off, according to him it was closer to 20 degrees advanced than it was to 10.
I have no idea how that happened...I think it's time for me to invest in a timing light. He set the timing to 10*, and the miss seems to have gone away completely.
BUT...strangely enough, the situation with the o2 sensor and the grounded Vf signal is the same!
You guys are going to hate me, but Jose checked my timing, and it was WAY off, according to him it was closer to 20 degrees advanced than it was to 10.
I have no idea how that happened...I think it's time for me to invest in a timing light. He set the timing to 10*, and the miss seems to have gone away completely.
BUT...strangely enough, the situation with the o2 sensor and the grounded Vf signal is the same!
Nah no hate here johnathan...been there done that
Timing was one of the 1st things I thought of
Glad it was simple!
Timing was one of the 1st things I thought of
Glad it was simple!
What, that Centech doesn't have a built in timing light? What kind of steaming pile of a meter is that?
jdub said:
LOL... didn't even think that would cause my problem...+1 to you!
jetjock said:What, that Centech doesn't have a built in timing light? What kind of steaming pile of a meter is that?
Ah, the Centech...A fine multimeter.
If your Centech is like the fine one I just pulled out of my drawer :aigo: , then set it to 2000m, that should read in millivolts from 0 to 2000. Your OX should be swinging from 200 to 800 on the meter.