I will reply piece at a time. It's a good photo -thank you- but I can't zoom in close enough to see what's happening on your TB without going blurry.
Blocked IAC? how did you compensate? by readjusting the throttle idle stop screw? If so, did you also adjust (if possible) your throttle position sensor to reflect that change?
check and see what that's (TPS) telling your computer - that may be the source of overfuelling. a few degrees may make for enough of a voltage change to get the computer thinking it needs to increase injector pulse duration.
Yes I compensated with the idle screw, yes I adjusted the TPS at least the same amount. Now I asked you to only make suggestions based on experience and preferably referencing specific gain that you have seen in MPG. I also did a lot of research on how the TPS functions, I also fitted an air/fuel ratio gauge for probably 2000kms after this modification. The ratio was always in the lean range, the TPS causes the fuel ratio to temporarily flare into a rich status when pedal is depressed for an acceleration phase, the further you press the pedal the richer it will flare to. It then returns to normal airfuel ratio. I discussed this at length with a guy who truly understands computer programs and basically the TPS doesn't do that much to ECU fuel delivery, as I saw by watching the gauge. I don't know what impact there would be turning the TPS the other way but I think I have checked and double checked that it is not causing me any problem.
Another thing I need to have you reconsider is that in your equation, Pressure is NOT irrelevant. (Why bother with converting to Kelvin if you're not going to take all the units involved in the published equation into account? just because you can show a bigger number with your use doesn't mean you're correct; you can't prove what that number MEANS because of the lack of reference to units) Remember, this is chemistry...and there are physics involved before the pistons can move turning a crank and transmission and differential and wheels.
Let's walk through a theoretical calculation using Standard Temperature and Pressure (16 degrees C - 29.92inHg) and one liter (or gallon or Sh!tload...doesn't matter) on one side of that equation :
P1 times V1 over T1 is (29.92 times 1) / 16. that works out to 1.87 ignored Units.
Now, we've got a running engine making 20" of vacuum in the manifold, so P2 is 9.92inHg, and there's still one volume of air, but if it's 70 degrees because you warmed it in a hot box, the numbers now work like this:
9.92 times 1 / 70, which works out to 0.1417 ignored units.
The equation doesn't balance. 1.87 does not equal 0.1417, regardless of the units
You'd need a LOT more air, a lot LESS vacuum (when was a vacuum leak a good thing?)
Ok Greg, I have no idea what you are doing here, either you've gone off on a tangent or you will need to explain further. I only said pressure is irrelevant because it is unchanged; and when both sides of the equation stays at the same value I can leave it out of the maths. A hot air box changes temperature of the air, the air always stays at atmospheric pressure- same pressure. I see that you have done the calculations with vacuum figures, I don't think what happens after the butterfly is relevant - but even if it could be argued; Where did you get the vacuum values from? If you are just going to assume values then you can pretend the density of air changes to whatever you want by "guessing" whatever vacuum values you want.
Also you must use Kelvin, because Kelvin is the zero point for temperature. Zero degrees Kelvin is the point at which zero heat exists. Your calculation is not correct when using degrees celcius, Nor with the guessed vacuum values. My calculation was correct. More science: Vapour point and Boiling Point are NOT the same thing. Read for yourself Note: it mentions pressures.
Again Greg. You don't know this about me but I know a lot about this field. Not saying that I can't learn some new application of it. I red the link you put up. But what is vapor point? I googled the term vapor point and it searched for vapor pressure and I did not find any definition of vapor point. Boiling point of water is 100 degrees C, So what temp is vapor point? You have mis-read (or misinterpreted) what I said about intercoolers. I said, "Intercoolers are used to cool the increased air charge from the turbo." Jamming more air into a container of a fixed size will change its pressure, because the Mass of air is increasing, so it's temperature must react to keep another equation balanced...and again, units matter here are we talking kilos or litres or what?
Again Greg, I am not sure what you are saying here. Please clarify. Your previous thread was clear that you do not want to try hot air induction due to the loss of density. Example you gave was turbo motors needing to intercool to gain density. I just pointed out that a lot of turbos dont worry about intercooling. Intercooling for density increase is only part of what the intercooler does for the motor. Therefore the intermittent use of intercoolers on turbo applications doesn't prove hot air induction will kill an engines performance. There will be a loss, which MUST be compared to the gain (better vaporisation) before an outcome can be stated. Don't change your engine - change your mind. Please. I'm trying to help you here. Start by looking at your throttle position sensor.
it has to agree with what the computer has been ingrained with (before we can teach it a new normal for the groove), and by doing what I suspect because of the IAC mod you've made, they are out of whack, and that'll make the oxygen sensor work in not-right ways...
I don't plan to change my engine and Im happy to change my mind and try any mod you recommend following any good experience you have had. I think I have ruled out ; by my comments any need to worry further about the TPS causing my motor to run rich.
Thankyou for your thoughts and I look forward to further ideas with a hopeful economy increase on this car.
Best regards, Neil
You guys seem to be digressing, and not considering the entirety of the equations. Vaporization point IS the boiling point, but that is determined by BOTH PRESSURE AND TEMPERATURE. (Ideals Gas Law or Law of Standard Temperature and Pressure)
Regarding moving the TPS, I wouldn't have. You must make your changes few AND INCREMENTAL. Don't change more than one variable, or it becomes impossible to know which mod caused whatever changes you notice. Takes TIME, but it must be invested up front to get a reliable result at the end.
One other thing is on the MASS of a substance in relation to it's BTU content (temperature). Warmer stuff is less dense. The only exception is water.
So, let's stop this back and forth arguing finer points of equations that are voiced incomplete. Consider the ENTIRE equation to get an ENTIRE answer...
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Ron - Neil would've had to move the TPS because he closed off the IAC (remember? You even commented on that back a few posts) and has now admitted he adjusted the idle stop screw on the TB as I guessed. I'm just not sure he moved it enough, if that's possible.
Neil - you said "For density of air the calculation is P1 times V1 over T1 equals P2 times V2 over T2." That's a balance equation - one side has to equal the other, so the variables have to be adjusted accordingly. That's what I was demonstrating. or trying to. We know atmospheric pressure and can infer the relative pressure (or measure the difference), we can assume a volume of air, we know the air temperatures. all my math proved is that the density of the air warmed to 70degrees in the hotbox was significantly (13 times!) LESS dense than the theoretical intake air at Standard Temp and Pressure, the point being you CANNOT take pressure out of the equation...and that it's probably the wrong equation to be using. Like Ron has pointed out, it fails to take Mass into account. I think PV=nRT (the Ideal Gas Law) might be the better one...n is molar mass. Mass Air flow sensors "measure" Mass of air in grams/sec, and some of them measure temperature too. Manifold Absolute Pressure sensors help the computer use that equation, and then it's reaction and instrumentation error get tweaked by the result from the oxygen sensor
Another thing Ron is right about - changing too many things too quickly. If you plugged the IAC valve and adjusted the idle stop screw to compensate and the TPS sensor to compensate for the previous compensation, you didn't give us a chance to diagnose how to get the groove to work on that engine if it didn't right out of the gate. Opening up the spark plug gaps only made it tougher, as did unplugging the oxygen sensor and adding a potentiometer to the MAF. Things that WILL work, as you've requested: put it back to stock, with just the groove and we can go from there. You've done a bunch of things that haven't worked - now let's take a step or 3 back to course correct and get moving in the direction you wanted to be headed originally.
Deal? This is about finding the right setup to save on fuel, correct?