O2 Sensor on Aspire

[boydg1]

.... The intent of my thoughts and suggestions here is this. To run the fuel injection system on the Aspire without ANY modern emissions control other than straight pipes, resonator and muffler like we used to many years ago on other engines. Now, how to go about this in a practical way is the question. That's what I am trying to put forth here. How to go about controlling the fuel injection system independently, either mechanically, electrically, or perhaps by its' own on-board computer without any modern day sensors other than perhaps a sensor to tell the injectors when to fire?:scratch:
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.... By replacing the carburetors on Festie's with the Weber 32/36 DFEV we have simplified the operation of Festie's engine with a number of benefits and less headaches. And, this is the way it used to be before emissions control came along.:thumbright:
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[htchbck]

or perhaps by its' own on-board computer without any modern day sensors other than perhaps a sensor to tell the injectors when to fire?

Let me first explain that yes, it would be easy to tell the injectors when to fire without a comp. What you can't really do without the other sensors is tell them how long to fire, which is just as important. What is boils down to is that you need a metered amount of fuel entering the engine. A carb does this by way of floats, jets, diaphragms, needles, etc.. An EFI engine uses sensor inputs and analyzes them to produce an output, which is how long to leave the injectors open which equals how much fuel goes in.

Therefore, when the carb guys switch to webers, they eliminate the tangled mess of vac hoses under the hood that help catch gas vapors and stuff for emissions purposes, but they still have the fuel metering system which is the internal workings of the carb. On an EFI car you could get rid of the cars factory fuel metering system (comp and sensors) but you would need to replace it with another metering system (megasquirt, for example). But having injectors firing random amounts of fuel, even at the right time, is hardly going to make an engine run efficiently, if at all.

As a side note I would like more info on these "fuel injected cars without computers"... not saying they don't exist, just not familiar with them. Closest thing I can think of was maybe the TBI stuff, but even that has a lot of sensors and a comp. And at any rate, I doubt any of the EFI type stuff they were running in the 80s is going to be any simpler or more efficient than what the Aspire has.

[Pu241]

Ok, you want less clutter and a simpler functional design.
You may well get that, but in converting an Aspire to a carb your going to do a lot of work.
And even then, I'm certain your not going to make it any more efficient.
What is the issue with EFI that you feel it needs replaced.

As far as emissions, specifically EGR, it also reduces peak cylinder temps which can cause over heating, burnt valves, and reduced exhaust component life.

[FestYboy]

AND a proper working EGR system INCREASES fuel milage... (i don't care if you don't believe it, it's true).

[boydg1]

…. Ok, once again I agree with you wholeheartedly in all here that you have said. And now that we all are on the same page, apples and apples and oranges and oranges, we can really discuss this. Perhaps in being somewhat brief I was a little too brief. I should have add: “ or perhaps by its' own on-board computer without any modern day sensors other than perhaps a sensor to tell the injectors the (metered amount) and when to fire? “. I can see now, I am going to have to do is some HOMEWORK. I do NOT recall right now how that fuel regulation was accomplished. I do know it was done and it worked well and was prized at that time and I believe it was on the Corvettes first in this country. There are people I can have a serious talk with and I would think resolve this question, And I will share the outcome with all of you. . ….To answer your other question “ As a side note I would like more info on these "fuel injected cars without computers". I think this question may very well resolve itself when I find out more information about the first question. . …. Now, this thread is turning into a good exploratory, informative discussion and to me that is what this forum is all about. .... I hope all that I have written comes through and is comprehensible because NONE of the sidebar "SMILIES" and editing menu above other than just typing is working, everything is running together. .

Let me first explain that yes, it would be easy to tell the injectors when to fire without a comp. What you can't really do without the other sensors is tell them how long to fire, which is just as important. What is boils down to is that you need a metered amount of fuel entering the engine. A carb does this by way of floats, jets, diaphragms, needles, etc.. An EFI engine uses sensor inputs and analyzes them to produce an output, which is how long to leave the injectors open which equals how much fuel goes in.

Therefore, when the carb guys switch to webers, they eliminate the tangled mess of vac hoses under the hood that help catch gas vapors and stuff for emissions purposes, but they still have the fuel metering system which is the internal workings of the carb. On an EFI car you could get rid of the cars factory fuel metering system (comp and sensors) but you would need to replace it with another metering system (megasquirt, for example). But having injectors firing random amounts of fuel, even at the right time, is hardly going to make an engine run efficiently, if at all.

As a side note I would like more info on these "fuel injected cars without computers"... not saying they don't exist, just not familiar with them. Closest thing I can think of was maybe the TBI stuff, but even that has a lot of sensors and a comp. And at any rate, I doubt any of the EFI type stuff they were running in the 80s is going to be any simpler or more efficient than what the Aspire has.

[FestYboy]

i got it, you want to convert an aspire to hilborne injection (mechanical). it uses a variable jet size that's opened via the distributor or other crank signal and there is variable fuel pressure via a vaccum signal averaged from several runners.

IT TAKES FOREVER to get these tuned right and they're not good at elevation changes.

i've found the most simple injection systems are TBI systems like from the GM iron duke 2.5L. look into those for a symple system. (hint: look for Metro LSi systems as well)

[boydg1]

As a side note I would like more info on these "fuel injected cars without computers"... not saying they don't exist, just not familiar with them. Closest thing I can think of was maybe the TBI stuff, but even that has a lot of sensors and a comp. And at any rate, I doubt any of the EFI type stuff they were running in the 80s is going to be any simpler or more efficient than what the Aspire has.

.... Here is a link, which should answer your 2nd question in part or completely and give you some insight were I am coming from especially in reference to the Chrysler's Hemi and the Corvette.

http://en.wikipedia.org/wiki/Fuel_injector

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.... It won't be until another week or so before I get to talk with the people I mentioned in POST #20 of this thread about the first question. Which I think will pretty much be answered by the second question above in the link. But I still will have a talk with them for my own satisfaction if nothing else.
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[htchbck]

That was a fascinating read! I knew about the Hilborne system being used in race cars (dirt track, etc.) but didn't realize it was ever available on street vehicles. While I don't think you'd see any efficiency gains or really simplicity gains either, I do think that it would be a very cool experiment to try out. Sounds complicated though