Drop in fuel economy
12-08-14, 03:36 AM
#16
Pit Crew
Thread Starter
No, and it was running fine last summer, winter, and most of the spring.
No on both accounts.
Everything is hooked up correctly. I did clean the MAF sensor this past weekend. One side was a bit dirty.
Nothing comes to mind, but I'll check today. Thanks for the feedback!
The primary sensor used by the ECM to determine the correct amount of fuel to be "delivered" is the MAF sensor. Because of the obvious range of operation (the large changes in the amount of engine intake air) of the MAF sensor is one sensor that can start producing readings (when contaminated, for example) that may not be "seen" by the ECM as erroneous and the ECM does not set a fault code (with the associated illuminated Engine Check Light). Is the intake ducting between the air filter housing and the throttle body connected correctly?
Nothing comes to mind, but I'll check today. Thanks for the feedback!
12-08-14, 03:44 AM
#17
Pit Crew
Thread Starter
No doubt its the fuel, usually around October the stations carry the winter blend gas that causes a decent drop in fuel economy. Most people have no idea. Trust me this is it
http://www.ehow.com/info_12071245_lo...-blending.html
http://www.ehow.com/info_12071245_lo...-blending.html
As such, using winter-blend gas will result in a maximum 1.7 percent reduction in fuel efficiency.
What I have been experiencing is an average drop from 27 down to 23 or so, which is more like 15%. I use the same gas stations and drive the same route as I have since I got the car in 2009. It has always given me consistent readings on the display. They may not be totally accurate, but they have been consistent.
12-08-14, 01:53 PM
#18
A couple thoughts:
a) - many report about a 10% mpg hit with winter blend. Which could have been in the pumps months ago. Don't rule it out. There are stations that pump "real" gas - find a website that lists them and find some in your area. Try that for a tank. The political nature of arguments regarding the efficiency of ethanol do not match the real world results, so I would trust actual field numbers vs. that fluff piece linked. The thermal content alone of two liquids does not equate to a straight-line mpg translation. Incredibly sloppy thinking there, or just plain ignorance. I'm going with plain ignorance as it also makes this statement:
Which is wrong by not a little, but a whole order of magnitude. "Average" motor oil is 30 weight. kinematic viscosity at 100C is 11 cSt. Tap water at room temp (20C) is 1cSt. So this guy is about as credible on cars as I would be on neo-Marxian feminist literary theory.
b) If you are not actually averaging metered fuel pumped/odo readings shown, it's not a reliable thing to go on. I do so, and the ES's computer is not usually within 10%, and often much more off than that. You are trusting that the sensors/inputs the computer uses have not aged, become dirty, etc. The equation the computer uses is the same and consistent, but only so much as the inputs have not varied. We don't know that.
c) With your mileage, you can consider cleaning your ISV in addition to your MAF, and changing or cleaning the PCV valve and blowing out the line - they clog, too. I saw a 4cyl toyota owner recently baffled at a mpg drop. Hunted and hunted and finally found a clogged pcv line, not the valve. Run some Seafoan through the intake, too, - not a bad idea.
d) Don't rule-out other ideas. Jack up the car and spin each wheel, see if they are spinning very freely. Bad bearing,cv, or sticky brakes can do it.
On d), I was hunting for months for some "missing" mileage on my SUV. Could not find a cause. Finally when a rear brake started to squeal, I examined it and the caliper bolts were sticking a bit, causing the pads to drag. I replaced with new pads and lubed it all correctly - mpg now back. The funny thing was, the drag on the driveline was enough the vehicle is now much smoother and peppier, and I should have noticed. Lesson: things can change so incrementally, you don't notice it. If I'd jacked it up and spun the wheel, I'd have caught it months ago before the squeal.
You are smart to monitor mpg and take it as a hint of something. I am very consistent about that myself.
a) - many report about a 10% mpg hit with winter blend. Which could have been in the pumps months ago. Don't rule it out. There are stations that pump "real" gas - find a website that lists them and find some in your area. Try that for a tank. The political nature of arguments regarding the efficiency of ethanol do not match the real world results, so I would trust actual field numbers vs. that fluff piece linked. The thermal content alone of two liquids does not equate to a straight-line mpg translation. Incredibly sloppy thinking there, or just plain ignorance. I'm going with plain ignorance as it also makes this statement:
At 220 degrees, the average motor oil has all the viscosity of tap-water
b) If you are not actually averaging metered fuel pumped/odo readings shown, it's not a reliable thing to go on. I do so, and the ES's computer is not usually within 10%, and often much more off than that. You are trusting that the sensors/inputs the computer uses have not aged, become dirty, etc. The equation the computer uses is the same and consistent, but only so much as the inputs have not varied. We don't know that.
c) With your mileage, you can consider cleaning your ISV in addition to your MAF, and changing or cleaning the PCV valve and blowing out the line - they clog, too. I saw a 4cyl toyota owner recently baffled at a mpg drop. Hunted and hunted and finally found a clogged pcv line, not the valve. Run some Seafoan through the intake, too, - not a bad idea.
d) Don't rule-out other ideas. Jack up the car and spin each wheel, see if they are spinning very freely. Bad bearing,cv, or sticky brakes can do it.
On d), I was hunting for months for some "missing" mileage on my SUV. Could not find a cause. Finally when a rear brake started to squeal, I examined it and the caliper bolts were sticking a bit, causing the pads to drag. I replaced with new pads and lubed it all correctly - mpg now back. The funny thing was, the drag on the driveline was enough the vehicle is now much smoother and peppier, and I should have noticed. Lesson: things can change so incrementally, you don't notice it. If I'd jacked it up and spun the wheel, I'd have caught it months ago before the squeal.
You are smart to monitor mpg and take it as a hint of something. I am very consistent about that myself.
Last edited by Oro; 12-08-14 at 01:56 PM.
12-09-14, 03:56 AM
#19
Pit Crew
Thread Starter
A couple thoughts:
a) - many report about a 10% mpg hit with winter blend. Which could have been in the pumps months ago. Don't rule it out. There are stations that pump "real" gas - find a website that lists them and find some in your area. Try that for a tank. The political nature of arguments regarding the efficiency of ethanol do not match the real world results, so I would trust actual field numbers vs. that fluff piece linked. The thermal content alone of two liquids does not equate to a straight-line mpg translation. Incredibly sloppy thinking there, or just plain ignorance. I'm going with plain ignorance as it also makes this statement:
Which is wrong by not a little, but a whole order of magnitude. "Average" motor oil is 30 weight. kinematic viscosity at 100C is 11 cSt. Tap water at room temp (20C) is 1cSt. So this guy is about as credible on cars as I would be on neo-Marxian feminist literary theory.
b) If you are not actually averaging metered fuel pumped/odo readings shown, it's not a reliable thing to go on. I do so, and the ES's computer is not usually within 10%, and often much more off than that. You are trusting that the sensors/inputs the computer uses have not aged, become dirty, etc. The equation the computer uses is the same and consistent, but only so much as the inputs have not varied. We don't know that.
c) With your mileage, you can consider cleaning your ISV in addition to your MAF, and changing or cleaning the PCV valve and blowing out the line - they clog, too. I saw a 4cyl toyota owner recently baffled at a mpg drop. Hunted and hunted and finally found a clogged pcv line, not the valve. Run some Seafoan through the intake, too, - not a bad idea.
d) Don't rule-out other ideas. Jack up the car and spin each wheel, see if they are spinning very freely. Bad bearing,cv, or sticky brakes can do it.
On d), I was hunting for months for some "missing" mileage on my SUV. Could not find a cause. Finally when a rear brake started to squeal, I examined it and the caliper bolts were sticking a bit, causing the pads to drag. I replaced with new pads and lubed it all correctly - mpg now back. The funny thing was, the drag on the driveline was enough the vehicle is now much smoother and peppier, and I should have noticed. Lesson: things can change so incrementally, you don't notice it. If I'd jacked it up and spun the wheel, I'd have caught it months ago before the squeal.
You are smart to monitor mpg and take it as a hint of something. I am very consistent about that myself.
a) - many report about a 10% mpg hit with winter blend. Which could have been in the pumps months ago. Don't rule it out. There are stations that pump "real" gas - find a website that lists them and find some in your area. Try that for a tank. The political nature of arguments regarding the efficiency of ethanol do not match the real world results, so I would trust actual field numbers vs. that fluff piece linked. The thermal content alone of two liquids does not equate to a straight-line mpg translation. Incredibly sloppy thinking there, or just plain ignorance. I'm going with plain ignorance as it also makes this statement:
Which is wrong by not a little, but a whole order of magnitude. "Average" motor oil is 30 weight. kinematic viscosity at 100C is 11 cSt. Tap water at room temp (20C) is 1cSt. So this guy is about as credible on cars as I would be on neo-Marxian feminist literary theory.
b) If you are not actually averaging metered fuel pumped/odo readings shown, it's not a reliable thing to go on. I do so, and the ES's computer is not usually within 10%, and often much more off than that. You are trusting that the sensors/inputs the computer uses have not aged, become dirty, etc. The equation the computer uses is the same and consistent, but only so much as the inputs have not varied. We don't know that.
c) With your mileage, you can consider cleaning your ISV in addition to your MAF, and changing or cleaning the PCV valve and blowing out the line - they clog, too. I saw a 4cyl toyota owner recently baffled at a mpg drop. Hunted and hunted and finally found a clogged pcv line, not the valve. Run some Seafoan through the intake, too, - not a bad idea.
d) Don't rule-out other ideas. Jack up the car and spin each wheel, see if they are spinning very freely. Bad bearing,cv, or sticky brakes can do it.
On d), I was hunting for months for some "missing" mileage on my SUV. Could not find a cause. Finally when a rear brake started to squeal, I examined it and the caliper bolts were sticking a bit, causing the pads to drag. I replaced with new pads and lubed it all correctly - mpg now back. The funny thing was, the drag on the driveline was enough the vehicle is now much smoother and peppier, and I should have noticed. Lesson: things can change so incrementally, you don't notice it. If I'd jacked it up and spun the wheel, I'd have caught it months ago before the squeal.
You are smart to monitor mpg and take it as a hint of something. I am very consistent about that myself.
01-30-15, 04:08 AM
#20
Pit Crew
Thread Starter
So I have continued to look into this problem. There is nothing dragging on any of the wheels, they all seem to rotate freely. The computer seems to be doing a fairly accurate job of calculating the MPG for each tank, as I have been using the same pump and stopping at the first shutoff over several fill-ups. Running my own calc gets me within about 0.5 MPG.
I'm wondering if there is something wrong with the fuel delivery, and perhaps that could be causing an issue. I think I talked about this at the beginning of this thread, but it happened again the other day.
While going to work, I was heading down an on-ramp to the highway. I was accelerating at about 50% throttle when there was abrupt loss of engine power. The best I could describe it was like hitting a rev-limiter, only this was at just about 2500-3000rpm. It lasted no longer than a second and I was off and moving again. Although I didn't feel as much this time, when this has happened before, I could feel some hesitation, like a slight miss, as it continued to move through the power band.
Unfortunately, there has been no check engine light to help me out. Any thoughts on what could cause that type of behavior?
I'm wondering if there is something wrong with the fuel delivery, and perhaps that could be causing an issue. I think I talked about this at the beginning of this thread, but it happened again the other day.
While going to work, I was heading down an on-ramp to the highway. I was accelerating at about 50% throttle when there was abrupt loss of engine power. The best I could describe it was like hitting a rev-limiter, only this was at just about 2500-3000rpm. It lasted no longer than a second and I was off and moving again. Although I didn't feel as much this time, when this has happened before, I could feel some hesitation, like a slight miss, as it continued to move through the power band.
Unfortunately, there has been no check engine light to help me out. Any thoughts on what could cause that type of behavior?
01-30-15, 06:15 AM
#21
So I have continued to look into this problem. There is nothing dragging on any of the wheels, they all seem to rotate freely. The computer seems to be doing a fairly accurate job of calculating the MPG for each tank, as I have been using the same pump and stopping at the first shutoff over several fill-ups. Running my own calc gets me within about 0.5 MPG.
I'm wondering if there is something wrong with the fuel delivery, and perhaps that could be causing an issue. I think I talked about this at the beginning of this thread, but it happened again the other day.
While going to work, I was heading down an on-ramp to the highway. I was accelerating at about 50% throttle when there was abrupt loss of engine power. The best I could describe it was like hitting a rev-limiter, only this was at just about 2500-3000rpm. It lasted no longer than a second and I was off and moving again. Although I didn't feel as much this time, when this has happened before, I could feel some hesitation, like a slight miss, as it continued to move through the power band.
Unfortunately, there has been no check engine light to help me out. Any thoughts on what could cause that type of behavior?
I'm wondering if there is something wrong with the fuel delivery, and perhaps that could be causing an issue. I think I talked about this at the beginning of this thread, but it happened again the other day.
While going to work, I was heading down an on-ramp to the highway. I was accelerating at about 50% throttle when there was abrupt loss of engine power. The best I could describe it was like hitting a rev-limiter, only this was at just about 2500-3000rpm. It lasted no longer than a second and I was off and moving again. Although I didn't feel as much this time, when this has happened before, I could feel some hesitation, like a slight miss, as it continued to move through the power band.
Unfortunately, there has been no check engine light to help me out. Any thoughts on what could cause that type of behavior?
01-30-15, 07:27 AM
#22
You guys should buy a Techstream mini VCI and with it you can do everything the delaer does. They work flawlessly.
If the fluel consumption is too high then you should check O2 sensors, vacuum leaks, air filter, spark plugs...
If the fluel consumption is too high then you should check O2 sensors, vacuum leaks, air filter, spark plugs...
02-09-15, 01:37 PM
#23
Pit Crew
Thread Starter
Thanks for the feedback guys. I have replaced spark plugs and air filter recently (within last 20k on the plugs).
So here is another interesting tidbit.
This morning this little stumble happened again. I was trying to take off quickly from a light (it was very early, no one around). The car took off, and all of the sudden, the car acted like it hit a rev-limiter. I mean zero response from the gas pedal for about a second. Once I crossed the intersection, I put the pedal down again and it happened. I then slammed the pedal to the floor trying to draw out some kind of CEL or something. The car accelerated like crap. Did the same thing on the way home if I get into the throttle. No CEL.
The car has 120k on it and I've never serviced the tranny. Could this be symptomatic of it slipping out of gear? Sure doesnt seem like it, but never hurts to ask.
Could the ECU need to be reflashed? It just seems like the engine/tranny go stupid.
Any thoughts appreciated.
Thanks guys!
So here is another interesting tidbit.
This morning this little stumble happened again. I was trying to take off quickly from a light (it was very early, no one around). The car took off, and all of the sudden, the car acted like it hit a rev-limiter. I mean zero response from the gas pedal for about a second. Once I crossed the intersection, I put the pedal down again and it happened. I then slammed the pedal to the floor trying to draw out some kind of CEL or something. The car accelerated like crap. Did the same thing on the way home if I get into the throttle. No CEL.
The car has 120k on it and I've never serviced the tranny. Could this be symptomatic of it slipping out of gear? Sure doesnt seem like it, but never hurts to ask.
Could the ECU need to be reflashed? It just seems like the engine/tranny go stupid.
Any thoughts appreciated.
Thanks guys!
02-09-15, 05:27 PM
#24
Unplug the battery, leave it overnight and start from there.
02-10-15, 04:01 AM
#25
Pit Crew
Thread Starter
Thanks for the reply.
What is the point of unplugging the battery? Is it to clear the ECU memory? Is there a way to do that (fuse or something) w/o disconnecting the battery?
Also, the techstream device you mentioned seems interesting, and not all that expensive. Does the one you linked work for the 07 ES350?
What is the point of unplugging the battery? Is it to clear the ECU memory? Is there a way to do that (fuse or something) w/o disconnecting the battery?
Also, the techstream device you mentioned seems interesting, and not all that expensive. Does the one you linked work for the 07 ES350?
02-10-15, 04:59 AM
#26
Yeap, works flawlessly.
Disconnecting the battery will reset your ECU.
Disconnecting the battery will reset your ECU.
02-10-15, 09:15 AM
#27
Pit Crew
Thread Starter
I will give that a try this evening.
Additionally, I just ordered one of the TIS Techstream units. Seems like a handy device to have around. I have an old XP laptop that should work perfect.
Do you think there would be any benefit to waiting to hookup the Techstream BEFORE I unplug the ECU? Perhaps there is some info/history that might be useful.
Additionally, I just ordered one of the TIS Techstream units. Seems like a handy device to have around. I have an old XP laptop that should work perfect.
Do you think there would be any benefit to waiting to hookup the Techstream BEFORE I unplug the ECU? Perhaps there is some info/history that might be useful.
02-10-15, 11:31 AM
#28
There would be some benefit, that's for sure.
02-11-15, 10:39 AM
#29
Pit Crew
Thread Starter
Does pulling the ECU-B fuse under the dash accomplish the same thing as disconnecting the battery when trying to reset the ECU? Trying to avoid having to re-do a bunch of settings if I can avoid it.
Thanks!
Thanks!
02-11-15, 12:36 PM
#30
Not sure about the ECU B fuse.
The only thing you have to set up after is the seat memory.
The only thing you have to set up after is the seat memory.