MPGuino stopped suddenly working..

[Quezacotl]

Hello!

I installed e85 fuel-box. The MPGuino did work before that, and during that.
I removed it, and then MPGuino does not display any info from injector.

I have several MPGuinos and all tested, so it can't be that.

At idle, the injector gives around 70Hz signal(Measured with Hz meter, i dont have oscilloscope).

I tried by adding some kind of lowpass-filter just to test what happens, 4k7 and 100n, and it brought some kind of signal to MPGuino, but it's very distracted.


Any thoughts what could be?

[AndrzejM]

I think that it's a disconnection somewhere between injector and guino, or maybe there's no proper ground connection to it.

[Quezacotl]

Yea that popped in my mind too when i was reading your other post,

Strange indeed... I presume the issue was based on some bad contact and it could disappear with different humidity, road bumps etc. Or it can be just noise from high voltage wires and that could disappear in dryer air, or again some road bumps.

I gotta check the injector wiring if there is something wrong. Was going to yesterday, but the weather was terrible. Today it is going to be sunshine

EDIT: I checked the wiring from the injector, but no luck.

[Quezacotl]

Now finally i managed to get it working!

The issue was umm.. well i dont know what the issue was, but i got it working again by moving the signal wire from next to injector to next to ECU.

Why i did'nt think that before? Well because it did work before too with the same setup...

[AndrzejM]

I think there was just a bad contact... When you hooked the cable to new point of the injector's harness it started to work again.

[Quezacotl]

No it was'nt that. I soldered it to the wire previously, and after new try, i moved it to another point, into the connector going to the injector. And after another try, i hooked it to the point where it first time did work. And this time, just near the ECU.
So i'm sure it was not a bad contact.

[WD40]

I was on a road trip back to Canada from California, and about halfway back my mpguino suddenly stopped working as well.
Then about the time I hit the border it suddenly started working again.
My guess.. maybe it over heated?
My GPS did a similar thing in the hot California heat on my next trip down.

[Quezacotl]

My issue was not on MPGuino itself, it was the car. I think the wiring harnesses are worn here and there and something just created a disturbance to the signal.

Maybe we should start an FAQ thread here concerning these kind of things. If someone could sticky it also.