Vf signal
04-28-2018, 04:51 PM
#22
Relatively sure mine are or were, BPR5ES flat top electrode..
I will agree the book says V and U grooved plugs, but I recall discussion about them (grooved plugs, iridium)..
Definitely 5ES, these are part store ones..
Don't seem to find images of what I got from Toyota..
*shrug*
05-02-2018, 07:47 PM
#23
Confused
So I’m confused about how to interpret my results and probably more importantly how exactly to read the Vf signal.
Here was my dates, procedure & results.
4/27: drove 5 miles or so warmed up the engine. Stopped and connected my voltmeter to the Vf signal and a know good ground (on the fender) while idling the voltage bounced back and forth (1 or 2 times a second) between .100 and .900V. Then I shut the engine off and measured again (ignition in “on position”) got a steady .020v
5/2: drove 5 miles or so warmed up the engine. Stopped & pulled the EFI fuse. Got my daughter at preschool. About 10 minutes later I put the fuse back in and drove about 1 mile (got engine back up to temp) and measured Vf signal as above. While idling I got a steady reading of .900v. Then I shut the engine off and measured again (ignition in “on position) and got .020 volts.
Then drove home about 5 miles and tested again. Idling = fluctuating between .500 and 900 engine off .020V.
So what is the correct way to measure Vf, idling or engine off? (Directions in the link above indicate T and E1 disconnected, run the engine and measure. They don’t specify running or not)
Why is it fluctuating at idle?
What is my actual Vf reading?
Thanks for your help, I’m just a noob and confused about how to read the signal.
Winky
Here was my dates, procedure & results.
4/27: drove 5 miles or so warmed up the engine. Stopped and connected my voltmeter to the Vf signal and a know good ground (on the fender) while idling the voltage bounced back and forth (1 or 2 times a second) between .100 and .900V. Then I shut the engine off and measured again (ignition in “on position”) got a steady .020v
5/2: drove 5 miles or so warmed up the engine. Stopped & pulled the EFI fuse. Got my daughter at preschool. About 10 minutes later I put the fuse back in and drove about 1 mile (got engine back up to temp) and measured Vf signal as above. While idling I got a steady reading of .900v. Then I shut the engine off and measured again (ignition in “on position) and got .020 volts.
Then drove home about 5 miles and tested again. Idling = fluctuating between .500 and 900 engine off .020V.
So what is the correct way to measure Vf, idling or engine off? (Directions in the link above indicate T and E1 disconnected, run the engine and measure. They don’t specify running or not)
Why is it fluctuating at idle?
What is my actual Vf reading?
Thanks for your help, I’m just a noob and confused about how to read the signal.
Winky
Last edited by Winky29; 05-02-2018 at 07:52 PM.
05-02-2018, 09:21 PM
#24
You are using a digital meter presumably, it's sample rate could be giving a discrepancy.. With a analog (moving needle), per the manual, you should see atleast eight fluctuations. If you don't see eight it (iirc) says to replace the sensor (there might be a step or two for confirmation)..
05-03-2018, 06:36 PM
#27
So I ran 2 wires into the cab, one ground and one connected to Vf, and connected them to an analog voltmeter. I pulled the EFI fuse for a while and went for a drive. Here's what I got once it warmed up.
While driving in closed loop the voltage would oscillate between .1 and .9 volts
With T and E1 connected I held the rpm at 2500 and got 10-12 oscillations in 10 seconds.
I pulled the jumper out and got a voltage right around .900V.
Here are my answers to the questions I posted earlier (correct me if I'm wrong);
Measure Vf with engine idling
It was fluctuating at idle because it was in closed loop and acting normally
My actual Vf reading is 1V which is ~1.25v (they said that the voltages can be off of the specific numbers)
Additionally, based on my results; the O2 sensor is good. My Vf value is on the rich side of normal (engine is adjusting the fuel down by 4-10%) but the ECU can handle it.
.
At this point I think it's safe to install a catalytic converter without it burning up right away due to running rich. I'm hoping that the cat will help with the hot garbage smell coming from the exhaust (real bummer with the soft top).
Any thoughts on these conclusions?
Thanks,
Winky
While driving in closed loop the voltage would oscillate between .1 and .9 volts
With T and E1 connected I held the rpm at 2500 and got 10-12 oscillations in 10 seconds.
I pulled the jumper out and got a voltage right around .900V.
Here are my answers to the questions I posted earlier (correct me if I'm wrong);
So what is the correct way to measure Vf, idling or engine off? (Directions in the link above indicate T and E1 disconnected, run the engine and measure. They don’t specify running or not)
Why is it fluctuating at idle?
What is my actual Vf reading?
Why is it fluctuating at idle?
What is my actual Vf reading?
It was fluctuating at idle because it was in closed loop and acting normally
My actual Vf reading is 1V which is ~1.25v (they said that the voltages can be off of the specific numbers)
Additionally, based on my results; the O2 sensor is good. My Vf value is on the rich side of normal (engine is adjusting the fuel down by 4-10%) but the ECU can handle it.
.
At this point I think it's safe to install a catalytic converter without it burning up right away due to running rich. I'm hoping that the cat will help with the hot garbage smell coming from the exhaust (real bummer with the soft top).
Any thoughts on these conclusions?
Thanks,
Winky
Last edited by Winky29; 05-03-2018 at 06:37 PM.
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