I have a little issue with knock after installing a MAF translator/LS1 MAF when my stock MAF failed. my O2 volts on the scanmaster bounces all over the place from 010 to 850 or so. Is it supposed to be constant? I just got the car and not sure what all the different values mean, but I do not think the O2 volts bounced around with the stock MAF.
Question about O2 volts
- Thread starter novi331
- Start date
Dan SS2471
Active Member
- Joined
- Dec 12, 2008
Do you mean while at idle, cruising? If so that's normal although seeing #s that high under those circumstances is not right. Meaning 800s.
If you mean it's doing it when ur in PE mode IE when ur going WOT for a few seconds, then no, that's not normal. You should be seeing numbers consistently in the mid 700s to mid 800s at WOT depending on how lean or rich it's running.
Did you make sure the translator settings are set correctly?
Dan
If you mean it's doing it when ur in PE mode IE when ur going WOT for a few seconds, then no, that's not normal. You should be seeing numbers consistently in the mid 700s to mid 800s at WOT depending on how lean or rich it's running.
Did you make sure the translator settings are set correctly?
Dan
I have same MAF set up as you...... mine only stays constant when at WOT you want to be in the 800's to be safe..... I like it between 800-815 or so... I feel safe . you can go down to high 700's but you need to understand what going on and understand the tune...... or you will be replacing head gaskets
When cruising it really goes all over from 010 to 780 but seems to stabilize under boost. It registered 18 degrees of knock once on the scanmaster once and 3.2 once and 7.7. Sometimes it doesn't register any knock. It runs perfect I just don't want to hurt anything! It is an e85 car so maybe I got some bad fuel on the last fill up. Too bad I got 20 gallons!
blackdeathtrap
smoking six barrel
- Joined
- Apr 1, 2010
tell us more about the car ei mods whats stock whats not how do the motor mounts look how control arm is to the down pipe what is the blm and int readings what are switches set at on the translator
i had that much knock for a bit but my car was a train wreck
i had cracked headers broke motor mount down pipe knocking on control arm faulty maf and faulty o2 and bent shaft on alternator
i had that much knock for a bit but my car was a train wreck
i had cracked headers broke motor mount down pipe knocking on control arm faulty maf and faulty o2 and bent shaft on alternator
that can be considered waaaaay rich
Mods are: TE44 turbo
power plate
reds volt booster
precision flow matched 60lb injectors
3 1/2 down pipe,dump.no cat.have gutted oem cat with parts.
cold air setup.oem airbox and related componets comes with car.
streatched stock location ic
torque strap.
two red xp pumps
custom 8 ga fp hot wire kit
new cam,timing set,roller cam button,lifters,springs.new oil pump and mods done by Richard Clark.
PTC 10" L/U torque converter...2800 stall
Thanks for all the feedback!!
power plate
reds volt booster
precision flow matched 60lb injectors
3 1/2 down pipe,dump.no cat.have gutted oem cat with parts.
cold air setup.oem airbox and related componets comes with car.
streatched stock location ic
torque strap.
two red xp pumps
custom 8 ga fp hot wire kit
new cam,timing set,roller cam button,lifters,springs.new oil pump and mods done by Richard Clark.
PTC 10" L/U torque converter...2800 stall
Thanks for all the feedback!!
I put a wideband on my car when I started pushing 11's and at the same 10.8-11.0AFR that I run with a little alky injected, my narrowband sensor will show anything from 720's to 810's depending on the day and its mood. 800's on the narrowband is probably safe, but you're probably leaving horsepower on the table as long as you are guessing at the true AFR which is what you are doing with the narrowband.
When your car is running in closed-loop mode, where the ECU is fine tuning the fuel mixture based on the oxygen (O2) sensor reading, it's voltage will rapidly change back and forth between about 0.1 to 0.8 volts (give or take). Why? Please see the link below for a little oxygen sensor 101...
http://www.aa1car.com/library/o2sensor.htm
(It's amazing what you can find on the internet if you take a second to look)
The times when your car is operating in closed-loop depends somewhat on who made your chip, but generally it would be at the following times:
1. When the car is cruising at constant speed or slowly accelerating, only after the car is "warmed up" (i.e. after the coolant temperature reaches a certain value, usually in the neighborhood of 120F or so, depending on who made the chip).
2. When the car is idling in Park or Drive, only after the car is "warmed up". Exception: some chips have a feature that idles the car in open loop to help smooth it out. If open-loop idle is enabled, you will see your O2 sensor voltage reading stabilize at a "rich" value (like 0.70 or something).
The times when your car is operating in open-loop, meaning it is NOT using the O2 sensor to tune fuel, are as follows:
3. When you are accelerating quickly, in other words, when you are in power enrichment (PE) mode. Any time you see any significant boost on your boost gage, you are in PE mode.
4. When the car is cold (coolant temperature is below about 120F or so, depending on who made the chip).
5. When the car is idling, only if the chip maker uses an open-loop idle control.
In all of the above cases "3." through "5.", the car is tuned to run rich, so the O2 sensor readings should be above 0.5 volts. The most important case is "3." above. One can very roughly estimate A/F ratio based on how high the O2 sensor reading goes while under boost. Keeping the O2 readings above 0.8 volts (800 millivolts) is a rough way to tell that you are running very rich (11.5 to 1 or lower A/F ratio), which is safe while under boost. As pointed out by others, this is not dead-set accurate. For example, when I'm making a 1/4 mile run, my O2 sensor reading starts at about 820 millivolts, and as I'm getting close to the finish line and the sensor is hotter, it gets down to about 780 millivolts. During my whole run, the A/F ratio is locked and doesn't change. So, using your O2 sensor to tune is more of a guideline, not a hard measurement. Always remember that an O2 sensor is more of a "switch", meaning that it "switches" from low voltage (0.15 or so) to high voltage (0.75 or so) when the A/F mixture switches from lean of 14.7 to rich of 14.7. So, it's a great tool for seeing if you are running very slightly rich or lean of 14.7 to 1 (stoichiometric), but it's not very good at telling you anything else.
Hope this helps...
http://www.aa1car.com/library/o2sensor.htm
(It's amazing what you can find on the internet if you take a second to look)
The times when your car is operating in closed-loop depends somewhat on who made your chip, but generally it would be at the following times:
1. When the car is cruising at constant speed or slowly accelerating, only after the car is "warmed up" (i.e. after the coolant temperature reaches a certain value, usually in the neighborhood of 120F or so, depending on who made the chip).
2. When the car is idling in Park or Drive, only after the car is "warmed up". Exception: some chips have a feature that idles the car in open loop to help smooth it out. If open-loop idle is enabled, you will see your O2 sensor voltage reading stabilize at a "rich" value (like 0.70 or something).
The times when your car is operating in open-loop, meaning it is NOT using the O2 sensor to tune fuel, are as follows:
3. When you are accelerating quickly, in other words, when you are in power enrichment (PE) mode. Any time you see any significant boost on your boost gage, you are in PE mode.
4. When the car is cold (coolant temperature is below about 120F or so, depending on who made the chip).
5. When the car is idling, only if the chip maker uses an open-loop idle control.
In all of the above cases "3." through "5.", the car is tuned to run rich, so the O2 sensor readings should be above 0.5 volts. The most important case is "3." above. One can very roughly estimate A/F ratio based on how high the O2 sensor reading goes while under boost. Keeping the O2 readings above 0.8 volts (800 millivolts) is a rough way to tell that you are running very rich (11.5 to 1 or lower A/F ratio), which is safe while under boost. As pointed out by others, this is not dead-set accurate. For example, when I'm making a 1/4 mile run, my O2 sensor reading starts at about 820 millivolts, and as I'm getting close to the finish line and the sensor is hotter, it gets down to about 780 millivolts. During my whole run, the A/F ratio is locked and doesn't change. So, using your O2 sensor to tune is more of a guideline, not a hard measurement. Always remember that an O2 sensor is more of a "switch", meaning that it "switches" from low voltage (0.15 or so) to high voltage (0.75 or so) when the A/F mixture switches from lean of 14.7 to rich of 14.7. So, it's a great tool for seeing if you are running very slightly rich or lean of 14.7 to 1 (stoichiometric), but it's not very good at telling you anything else.
Hope this helps...
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