Yet Another Guino Help Thread

[Nevyn]

Wow, makes me feel better. I put mine on, tapped directly at an injector. Wouldn't power up from the 12V source I had (got backlight, but no display), so I gave up. Wife went to use car, wouldn't start. So, I ripped my wire off the injector and cranked the engine while pumping the gas til it caught......stank like gas something terrible for a bit, and ran really rough for about 30 second until it got its brain back in order. I'm going to look for a different spot to tap the injector line, and move the 100k resistor to the engine side indtead of the guino side.

Turns out in my car, the ECU is UNDERNEATH the engine coolant tank in the engine bay - they just HAD to make my life difficult.........

[dcb]

I suspect you managed to ground out the injector (IT was stuck open)

[dcb]

I forgot about this page, it is referenced on the main wiki page:
Mpguino tests - EcoModder

[Intrigued]

Originally Posted by wagonman76

It must have burned some fusible link because it didnt blow any fuse.

OOOOHHHH I Hate fusible links!!! Look just like a regular wire, but when they burn out YOU CAN'T TELL IT!!!

You have to check voltage at the terminal and after the link to tell if the stupid things are burned out or not. We used to pull on them to see if they stretched a lot... which meant the wire inside was burned out...

[i_am_socket]

After many tense hours of me going "ohcrapohcrapohcrapohcrap" and my fiance giving me the stink-eye, we called an old co-worker of hers that does automotive and industrial electronics for a living.

One Might Mouse theme song later, he shows up and says it's just a blown fuse. An hour of laying upsidedown under the dashboard and testing all the fuses in the engine compartment (why have one fusebox when you can have three?) we find the blown fuse. I have spares of that amperage but they're too big and the spares they provide are a little high so he swapped in a 30 for the 20.

So now he's all interested in how and why I decided to fry my car and he helps wire in everything correctly and without destroying the wires with the clip-in taps. Now everything is wired up and connected and very nearly working.

Turns out I really did have the wires connected to the phone box backwards and should have just followed the installation instructions first before deciding I knew better. The Guino was actually powering itself off the fuel injector line and using the VSS as the ground. I'm surprised the whole thing didn't explode.

Anywho, so now I have a 3/4 working MPGuino. Speed is now pretty darn dialed in, power and ground are solid, but I'm not getting the fuel injector signal. It's definitely tapped into the ground side of the injector and there's voltage coming across but it's not pulsing that I can tell from the multimeter and the Guino thinks I'm EOCing and showing 999999 Tank MPG. If only it were true

Maybe I'm just a bit slow these days, but I'm not quite understanding the screen descriptions on the wiki. Big X and status I get, but the default custom and the instant displays I'm having issues translating the description to the one or two letters I see on the screen. Here's what I saw driving in to work this morning on the custom screen:

MG 999999	S.....57.30
GH 000000	C...999999

I'm guessing MG is MPG and GH is GPH, S is fairly obvious, but what is C? Right now I think it's just telling me the speed of light...

[dcb]

C is the "current" mpg, the average mpg for the current trip.

The current trip resets after 7 minutes of no speed or injector signal or button activity.

[i_am_socket]

Ah. I think the wiki needs some more clarification in details and formatting. If it'll help my dumb @$$, I'm sure it'll help others

*edit* i'll just add to this post....
the backlight has issues. i turn it up and as soon as the backlight level text disappears, so does the backlight.

current status: power is good, vss is good, no injector pulses, wonky backlight.

*edit2: the revenge*
Backlight issue fixed by unplugging and plugging back in. Hooray! Next issue, which i think might require slightly more work (ie programming flash), is that the Guino resets when shutting off the engine; either for EOC or just turning the car off. I'm guessing it's the brownout voltage problem?

Also, anyone have any thoughts on the lack of injector data? The solid 12-13 volts coming from the ground wire is kinda throwing me.

[Intrigued]

Originally Posted by i_am_socket

Also, anyone have any thoughts on the lack of injector data? The solid 12-13 volts coming from the ground wire is kinda throwing me.

You've lost the ground on that wire, or else it isn't the ground wire to begin with. No ground wire will show batt voltage... Maybe it's been cut by a previous attempt to tie into it...

You might check a schematic again to make sure on the colors of the wires...

[i_am_socket]

So I'm reading the other help threads and come across dcb's comment in the Guino KIT thread:

any injector will work, it's just a question of which wire (of two possible wires). If you unplug the injectors and turn on the ignition (not start), you can probe an injector harness plug, you want the lead that doesn't have 12 volts on it when measured to ground.

What do I do when both wires have 12 volts (power on, engine off)?

[dcb]

unplug all injectors that are ganged together. I'm guessing that some of your injectors fire at the same time. Got a link to a schematic?