SuperMID installation - help needed!

[GasSavers_Yoshi]

Hi Matt,

Sorry for my late response. I was out of town these days...
Thank you very much for you detail testing.

* Speed sensor circuit
I agree the circuit-A works best.
But, I guess it got some noise too, which means a single pulse recognized multiple pulses.
I wrote it "noise", but you can refer it switch bouncing or chattering.
Please refer to the attached figure.

You wrote your speed sensor probably sending 2 pulses per revolution. If the number is correct, the distance parameter' should be about 5144, twice as 2572(4 pulses/rev).

I'll try to make another interface circuit including the noise cancelling capability.

* Injector pulse
I think the 0.0 msec number is caused by overflow of the counter value.
Usually, the injector pulse goes to 0V when the injector is ON state.
But, I think your injector pulse is opposite, 0V-OFF/12V-ON.

I'll try to program of the processor to meet the signal above.
Please give me about two weeks and I'll send them to you.

Regards,
Yoshi

[landspeed]

Thank you very much

Is it possible to expand the range of distance parameters, just in case? It seems I needed to enter a correction value of '960' on superMID, but, as you say, once the noise is removed from the circuit, it might end up needing a much higher value!. The reason I say this is because:

(1) My speed sensor states (in the manual) that it switches on/off two times per revolution
(2) On my speedometer, it says '60MPH = 1024rpm', so... At about 96km/hour, the speed sensor will be switching on/off 34.133 times per second, which is therefore the same as 0.78m travelled per cycle of the
speed sensor output. Is this OK for SuperMID? I write all this because my car is so old, the outputs might be very different to more modern cars!

Thank you very much for all your help

Matt

Edit : tonight, I will scan + post the diagram of the fuel injector wiring, in case it helps, and to make sure I have indeed done it correctly!

[GasSavers_Yoshi]

Originally Posted by landspeed

Thank you very much

Is it possible to expand the range of distance parameters, just in case?

Sure! The next program will have the expanded range.

It seems I needed to enter a correction value of '960' on superMID, but, as you say, once the noise is removed from the circuit, it might end up needing a much higher value!. The reason I say this is because:

(1) My speed sensor states (in the manual) that it switches on/off two times per revolution
(2) On my speedometer, it says '60MPH = 1024rpm', so... At about 96km/hour, the speed sensor will be switching on/off 34.133 times per second, which is therefore the same as 0.78m travelled per cycle of the
speed sensor output. Is this OK for SuperMID? I write all this because my car is so old, the outputs might be very different to more modern cars!

Thank you for clarification.
The '60MPH = 1024rpm' specfication is same as Japanese standard, '60km/h = 637rpm'.
The 10m unit measurment will be done at the 16 bit accumulator is overflowed at 65536 value.
We need 10m/.78m=12.8 pulse to overflow, then the parameter becomes 65536/12.8=5120 in theory.

Edit : tonight, I will scan + post the diagram of the fuel injector wiring, in case it helps, and to make sure I have indeed done it correctly!

Yes. I think the diagram will help a lot.

Regards,
Yoshi

[landspeed]

This is the diagram. The ECU (the box near the bottom) is also connected to ground at several points elsewhere, not shown on this bit of the diagram.

Thanks

Matt

[GasSavers_Yoshi]

Thank you for the diagram.
It looks nothing strange, then only the symptom is strange.
Anyway, I'll send you another chip and interface board.

Yoshi

[landspeed]

Old thread resurrection - to let anyone reading this thread in the future know what the problem / outcome was

(1) Yoshi was very helpful throughout - and helped solve the problem
(2) The problem with the injectors was that my car uses a bizarre pulse-width modulation system (which is rare), due to having low-impedance injectors which would burn out if left switched on all the time.
(3) The speed sensor on my car is just a bit dodgy but improved with the circuit change.

Outcome:

(1) SuperMID will now work (with an additional small circuit) on cars with PWM fuel injectors - meaning that the problem discussed in this thread won't happen again, and SuperMID should now work on practically any injection vehicle
(2) I am beginning to obtain unbelieveable MPG (for my car) with the SuperMID!

[CO ZX2]

Originally Posted by landspeed

Old thread resurrection - to let anyone reading this thread in the future know what the problem / outcome was

(1) Yoshi was very helpful throughout - and helped solve the problem
(2) The problem with the injectors was that my car uses a bizarre pulse-width modulation system (which is rare), due to having low-impedance injectors which would burn out if left switched on all the time.
(3) The speed sensor on my car is just a bit dodgy but improved with the circuit change.

Outcome:

(1) SuperMID will now work (with an additional small circuit) on cars with PWM fuel injectors - meaning that the problem discussed in this thread won't happen again, and SuperMID should now work on practically any injection vehicle
(2) I am beginning to obtain unbelieveable MPG (for my car) with the SuperMID!

landspeed. How unbelievable is it? Do you have a calculated fillup to try and verify your SuperMID figures? Do not make any more 2 gallon fills, that is hard on me. Go GasMisers5.

[landspeed]

Unbelieveable for me (not compared to your MPGs, unfortunately). I have currently got 375 miles for slightly over half a tank. I got to the 0.5 tank mark at 330 miles, usually this is at 240-270mpg when doing highway drafting (my best MPG) but this tank has been lots of cold-start short journeys. It may be as high as 58MPGus, but, I have to wait a few more days, as I am still calibrating the SuperMID (noting down the figures after each journey)

RE the 2-gallon fill - that was a mistake, because, I thought the limit was 2 (not 3) gallons. But I remembered wrong!.

I did manage to get a (roughly) 68mpgUS segment today - this was over 25 miles with a few hundred feet elevation drop (with a 62mpgUS segment on the journey 'uphill' before that). These figures depend on the accuracy of the 2-gallon fill - which I think was quite accurate due to same method, very slow filling each time, same pump).