rennycornelius

ha ha ha !!!!!!!!!!!
nice one.......

__________________
The Magician"

sam9s

Nope I know what ignition timings are......what according to you is fuel mapping????........according to me (experts correct me if I am wrong) as I said in my earlier post as well "Fuel mapping is a theoratical graph that displays the optimum fuel enrichment at a given RPM. This fule map is used as an input for regulating air/fuel mixture"
Now that regulation can be controlled by a sophisticated system call EFI or not so sofisticated else wise but regulation has to happen which is what fuel mapping is.........

sankar

I had to look up the earlier post.

Fuel mapping happens, yes you are correct. Carburetor does the fuel mapping in a non FI bike. But electronic fuel mapping does not happen in a non injected bike. So in short TPS doesn't help in fuel mapping. GS150R does not have electronic fuel mapping.

sam9s

Arrre I quoted what I said in my earlier post...no need to look up...may be you missed it ....i have removed the quots and made the statement bold to make it more clear.......


yep that is what I meant.....with EFI fuel mapping does not happen electronically but it does happen......BUT I would still differ from you last post TPS doesn't help in fuel mapping........NOPE It does according to me (experts correct me if I am wrong again )......

The TPS sensor signal is used by the Engine Controll Unit (ECU) as an input to control/alter various parameters including fuel mapping.
The ECU computer needs this information to change the air/fuel mixture.....
Do not underestimate TPS in front of EFI.......

TPS senser is also used an as input to controll ignition timing and fuel injection timing as well...(Which EFI does electronically I know......) and I am sure TPS signals must be used for quite a few other parameters as well.....

sankar

Ok if you say TPS helps in fuel mapping could you tell me how that is done? Could you tell me how the amount of fuel fed into the engine is altered according to the signal from the TPS?

sam9s

lol....I am not an engineer, neither an expert (Though I hope few from xbhp come forward and help clearing things out as well)..... but since you seems to defy its my pleasure to dig further as that enriches my own knowldge as well....... :-)
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The sensor is usually a potentiometer, and therefore provides a variable resistance dependent upon the position of the valve.

TPS converts electrical resistance (zero to 5,000 ohms scale, ±25%) to a voltage that the computer interprets when setting ignition timing, fuel mixture and idle speed. It's mounted on the end of the throttle arm that's opposite where the throttle cable hooks up, and has 3 wires (5V, signal and ground). 5V are supplied to the TPS from the VC terminal of teh ECU. The TPS voltage signal is supplied to the VTA terminal. The ground wire from TPS to E2 terminal of teh ECU completed the circut.

The TPS uses a three pin connection to the wiring harness



.To detect the position of the throttle plate, 5 volts DC is applied to pin one, which is at one end of the potentiometer; the other end is grounded, and the wiper of the potentiometer reads the voltage resulting from the resistance.

• When the throttle is closed, the output voltage is between 0.4vdc (volts DC) and 0.7vdc.
• At Wide Open Throttle (WOT), the throttle is opened the output voltage is between 2.60 vdc and 3.00 vdc.
• Between closed and WOT the voltage ranges between 0 vdc and 2.60 vdc.

When the logic module senses the throttle position wide open throttle(WOT), the logic module exits closed loop and richens the fuel mixture for the engine. This will provide more power at wide open throttle while protecting the engine at higher boost levels by providing more fuel.
While at partial throttle positions, the logic module uses the TPS sensor signals to improve reaction times of air/fuel mixture adjustments........

If you want the exact voltage setting and how the TPS is mapped I can dig that as well but I am too tired and I guess I have given enough to give you a start from some more digging.....

Andante

I hate to burst your bubble, but on a carburetted bike no kind of electronic control can be exerted over the amount of fuel entering the engine. A carburettor is driven purely by the laws of physics.

That is leaving out those complex carburetters that have been developed in the past which had some sort of motor driven mechanics to change the mixture, they turned out to be more expensive, complex and prone to failure than EFI in the end.

The only system currently in the market that can actually actively change the amount of fuel entering the engine is a closed loop fuel injection system, which requires a lambda sensor in the exhaust to sense if the engine is running rich or lean. None of the indian bikes currently comes with this kind of FI. (SBKs have it since they are expensive imports.)

What you find on indian bikes is open loop FI, and it has no way of knowing if an engine is getting the right amount of fuel. That is why the service centers need to do CO setting on those bikes. (See the P220 thread for example, even the R15 needs the same treatment.) What open loop FI does do is measure the manifold pressure and throttle position to determine the expected amount of fuel to feed to the engine (using fuel maps build by the manufacturer).

So the only thing that a Throttle Position Sensor is good for in a carburetted engine is to help control the ignition advance to be used. This is because a larger throttle opening causes the carb to feed more fuel into the engine and that in turn needs a larger ignition advance to make the most of it. And ignition advance is one of the most important things to get right. An engine would run very very bad without it.

As for carbs vs FI, it turns out carbs are also surprisingly good at fuel metering, given the right carb for the engine. So nothing is really lost in having a carb, except a bit slower throttle response and the need to use a choke to keep a cold engine running. Power on a carb can be as good as with FI, just that FI would generally be a bit more efficient, due the fact that it can actually do things that a carb cannot. (Like inject fuel when a carb would normally not provide any.)

sankar

Man, I do know what a TPS is and how it works. But tell me how TPS does what i have highlighted in bold in your post. Leave the part where TPS sends a signal to the logic module (where does it sit?), but the rest i would like to know.

What's a logic module? Is it electronic? How does it richen (supply more fuel) the fuel mixture?

sam9s

I love when bubbles are burst....lol we are just have discussions, not a contest.....and I love discussions........ so we continue,,,, the carburrator itself maybe drawn by physics but the the valves could be controlled electronically.... TPS only used for ignition is something I doubt, that means there is no control over fuel map in these bikes........if that is the case the entire meaning of TPS changes and we should not even call these "things" as TPS......they may be just a small circuitry that helps the ignition is all we should say.....

sam9s

Oh man as I said I am not an engineer, the last post was almost dug out, which even you can do.......use uncle google, and if you find any info that clearly states that TPS does not help in fuel mapping...share with us.....As I said I might be wrong............

you can read about more technicalities about position sensors including TPS at this link.... its a pdf file.....

http://www.autoshop101.com/forms/h33.pdf