MPGuino release one workspace

[dcb]

rmccomiskie, can you unplug an injector and measure the ohmage of it? It did not show this behavior in .74?

Coyote, which car (and any circuit mods?)? You have like 50 cars

I ask because .75 looked a lot better when I tested it.

[Coyote X]

I ran .75 in my Astro today. When it is reading proper looking numbers it does seem more stable. I need to change some variables on the custom screen to see if I can figure out where things aren't working right. But it seems like if the pulse width is a certain range the gallons per hour goes way up and it takes a while to settle down and read properly again.

I will probably just run .74 tomorrow and Thurs just to make sure my simple opamp circuit is working 100% with both types of injectors. If it seems to stay consistent on both types. I think it might be worth going to maybe a V1.1 hardware revision with the op amp built in. Just 1 pot and 1 8 pin dip so it isn't much to add to the design. I am messing with some other stuff right now trying to get the opamp to output ttl voltages so it can do away with the zener and resistor. That way it is just swapping 2 parts for 2 bigger parts

[rmccomiskie]

Originally Posted by dcb

rmccomiskie, can you unplug an injector and measure the ohmage of it? It did not show this behavior in .74?

I ask because .75 looked a lot better when I tested it.

The injectors are 16 ohms. The behavior was the same in v0.74.

[dcb]

rmccomiskie, can you maybe post a pic of the scope picture?

You are tapped into the switched positive side of the injector circuit?

[rmccomiskie]

Originally Posted by dcb

rmccomiskie, can you maybe post a pic of the scope picture?

You are tapped into the switched positive side of the injector circuit?

There are 2 connectors on the injector. I checked each with the scope. One had no pulses, just noise. I tapped the other one that has the pulses shown below.

Single pulse from ECU @ 30mph (approx. 660uS):

Single pulse from injector @ 30mph (approx. 550mS):

Note the timescale differences. Does that look like a proper injector signal?

Multiple pulses from ECU @ 30mph: (3 inj pulses per rev, 1000/(28mS*3)*60 = 1428rpm)

Multiple pulses from injector @ 30mph: (1 inj pulse per 2 revs, 1000/(90mS/2)*60 = 1333rpm, close enough)


ECU, coasting @ 30mph with throttle closed (flat line):

INJ, coasting @ 30mph with throttle closed (very narrow pulses):


Because of the timescale differences, I assume that the ECU scales the pulses down so they don't overlap when all 6 injector pulses are merged in the same signal.

I have only run the MPGuino off the ECU signal. I have not tried the injector signal directly.

[2003protege]

Fascinating stuff.

[Coyote X]

mine on 0.74 still shows strange readings when coasting down with no throttle. Once it gets to idle it reads correctly.

Guess I smoked another opamp trying stuff out

[dcb]

Thanks for the update Coyote, didn't think .75 was a downgrade

rmccomiskie, you have to tell me what equipment you are using (especially if it's affordable). That is a nice suite of data. Also, I wondered if you can (or have) try changing:

attachInterrupt(0, processInjOpen, FALLING);
attachInterrupt(1, processInjClosed, RISING);


to:

attachInterrupt(0, processInjOpen, RISING);
attachInterrupt(1, processInjClosed, FALLING);

and using an injector tap. That injector signal looks good, but inverted. It might take a little more tweaking than just swapping the edge processors (i.e. funny business when engine is off) but hopefully it will be an improvement.


The ecu signal might be an "area under the curve" thing, don't know. but the decel ECU graph would not be detected correctly certainly.

[americasfuture2k]

Originally Posted by americasfuture2k

so what fuel injector low do i go after on my 08 since its obd ii and that has individual injector control? of course that is just at low rpms, which is what i will be in most of the time. or is it individual control in low like idle low rpms?

EDIT: also, what do i need to change to have my greeting message stay on a bit longer??

.....-_-.....

[dcb]

any injector you want, don't care about the message