Last post on Nov 19, 2012 at 7:45 AM
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Car Safety, Exterior, Fuel System, Performance Mods, Auto Body, Engine, Fuel System, Oil, Paint, Transmission, Alternative Fuels, Diesel, Hybrid Cars, Fuel Efficiency (MPG), Car Warranties, Coupe, Convertible, Hatchback, Truck, Sedan, Wagon, SUV, Van
#108 of 117 Re: OBD-II Interface and SW to improve Engine Fuel Economy [Mr_Shiftright]
Sep 26, 2005 (5:24 pm)
this isn't my domain, but yeah, when someone says they are getting 17HWY, and the vehicle is supposed to be getting 25 (and everyone else is), and there are no codes, yeah, i think the sensor is "bad", but still providing a within-range measurement that is being acted upon to the detriment of the combustion cycle.
really, i don't think sensor validation is as critical in a vehicle, nor do they want tight tolerances, because of the false positives and desire for running reliability...this then comes at the detriment to detecting loss of efficiency due to the transducer measurement itself.
am i totally duped? i don't know...this isn't my domain of expertise, but I got a sneaky suspicion that the car makers are using adaptive control within limits, and are diagnosing transducer failures within limits, but in the realm of possibility are vehicles runnning needlessly derated. they ain't tossing codes (till something like the CAT is fully gone), or the wires are falling off the 02 sensor. meanwhile, the person is just burning gas faster than necessary.
can you catch this during emissions testing time? i don't know - can you and have the vehicle not pass?
#109 of 117 Re: OBD-II Interface and SW to improve Engine Fuel Economy [user777]
by MrShift@Edmunds HOST
Sep 27, 2005 (7:02 am)
Well I don't know, except to say that gas mileage is subject to SO MANY variables that have nothing to do with the engine management system per se.
#111 of 117 Re: Automotive Science or Voodoo? [dialm4speed]
Oct 06, 2006 (3:37 pm)
Yes in fact I distribute the product. I have used BlueSky in every car I own every time I fill up. I have been doing this for the past six years. I have spent thousands of dollars testing BlueSky here in California and in Mexico, Japan, Europe and Sri Lanka. It was originally developed for diesel fuel and we found it to work very well in gasoline as well as bio-diesel, ethanol & methanol.
It is not a device but a liquid fuel additive one adds to your fuel every time you fill up. Use about 1-ounce for every ten gallons of fuel. It will clean your fuel system & combustion chamber. The theory behind all this is that you will have an even dispersement of fuel in the combustion chamber which has been cleaned. This clean combustion chamber, free of carbon build-up will provide the best environment for a 'complete burn' of the fuel. This means the more fuel gets burned=less pollution and more power! If you have a dirty fuel system or combustion chamber this will maximize your fuel consumption and may improve it substantially. Thank you for the opportunity. If you have any more questions please feel free to contact me.
#112 of 117 Re: Automotive Science or Voodoo? [dmcvickar]
Oct 10, 2006 (11:49 am)
Sounds like you really believe that stuff makes a difference.
Blue Sky? I think I would find another product line!
#113 of 117 Re: Automotive Science or Voodoo? [dmcvickar]
by MrShift@Edmunds HOST
Oct 11, 2006 (7:17 am)
This seems counter-intuitive, since a light carbonization of the fuel chamber would increase compression and hence power. I don't see the relationship of carbon to a "complete burn" one way or the other.
I could see where a fuel injector CLEANER would give a better spray pattern but this has nothing to do with the combustion chamber.
If the claim is that the additive changes the chemical composition of gasoline itself, I'd like to see the science behind that claim and what molecular changes have occurred.
#114 of 117 Cavalier Diagnostics
Jan 19, 2011 (5:14 am)
Hello, I am having idle problems with my 1998 Chevy Cavalier Z24. The car runs great when I first start the vehicle but after it warms up it will start running poorly. It is most noticable after it warms up and then I shut it down for a few minutes (like running into the store), after I re-start the car it accelerates terrible. Idles fine but won't accelerate.
I borrowed a Actron Autoscanner from a buddy of mine and ran diagnostics on the vehicle, this is what I got:
Trouble codes, ignition on, engine off:
Diagnostic codes, Engine running:
ABSLT TPS(%) 0.0
CALC LOAD(%) 19.2
MAP ("HG) 8.9
IAT (F) 63
IGN ADV(DEG) 17 TO 26
LT FTRM1(%) 21.9
ST FTRM1(%) -9.4 TO -14.8
FUEL SYS1 CLSD
FUEL SYS2 N/A
ST FTRM11(%) -10.9 TO -14.1
O2S12(V) .000 TO .005
From what I've been able to read into this is that my map sensor isn't working correctly and my downstream O2 sensor is faulty. I'm clueless regarding the other information. Are they normal or not?
Thanks in advance!
#116 of 117 Re: Cavalier Diagnostics [smonday]
Nov 19, 2012 (5:48 am)
I don't think the P0171 code means that the downstream O2 sensor is bad. Just that it's detecting an excess of oxygen on the exhaust flow. Which could be caused by a bad MAF sensor.
All the rest of the codes could be a result of the excess oxygen in the exhaust.
#117 of 117 Re: Cavalier Diagnostics [srs_49]
by MrShift@Edmunds HOST
Nov 19, 2012 (7:45 am)
yep P0171 is tricky. Many a good 02 sensor has been replaced because of that code.
MAF sensor is a good guess; also coolant temp. sensor can throw this code; perhaps even a vacuum or exhaust leak.