MPGuino rebooting and freezing also... Power issue?

[tygertec]

I'm back at it again

Cleaned the battery posts real good and cut more ventilation in my enclosure. So far it seems to be a lot more stable. It rebooted one time for sure, possibly more. I may cut more ventilation holes in the enclosure. If that doesn't do the trick I'm going to install a power filter to smooth out the dips/spikes.

The only problem now is that I think I shorted out the VSS in my gauge cluster while testing stuff with the multimeter and now I have no speed signal. Doh! It was kind of irritating using the sensor off the combination meter anyway because it didn't put out a signal when the key was off. I'd like to get an aftermarket sensor that runs even with the car off. But I may create a new thread if I can't find any similar posts.

Thanks everyone! You guys are great! (Especially dcb!)

[drbobwoolery]

I am running into the same lockup issue described above. I put another diode from the cathode of the one that supplies +12V to a 9 v battery. This way, the regulator sees the higher of the two, and the 9 volt alkaline battery only supplies current occasionally and for short periods.

First try, I ran it in BIG INST mode driving to a friend's place. Upon restarting, the unit was stuck in BIG INST OOO, even when driving, and did not respond to the buttons. Fully interrupting power by disconnecting both supplies for 30 sec or so reinstated function. I believe the power is bone reliable, at least as far as dipping too low for the regulator.

I have v0.82, so maybe there is a bug in the code that shuts down after a timeout. Locking up has happened when just driving, or perhaps getting the display back to inst mpg when it has reset itself.

The car is my 49state 4door 1991 Metro. All connections are made about an inch from the connector on each of the 4 wires at the ECM. These are led out and spliced to a connector from an old power supply. After I messed up the first crimp, I just went to the junk box for a power supply. the 9 volt battery sits behind MPGuinio in front of the fuel indicator.

Do we perhaps need shielding?

[dcb]

Hmm, I am wondering about the commonality here. You both have old-ish cars with possibly old reed switched vss's. Can you try disconnecting the vss lead (lift the retaining tang at the plug or dyke the lead) and see if it runs more reliably? If you put it on the current screen it will show gallons to the 1/100th and the custom screen has an instant gph reading on it.

[tygertec]

I was reviewing this thread and noticed that one of the posters brought this out:

"One thing I noticed is that my injectors have 12V on each wire with the ignition on. car not running."

He has a 93 Toyota Previa if I remember correctly. I believe my mechanic friend mentioned that there are 12V on each injector lead in my 90 Toyota Corolla. Perhaps that could be our commonality???

My unit hasn't been freezing much at all (Still haven't installed the rcl filter. Super busy!) Since my VSS signal isn't working I've been relying on the gph field, although I do still have the VSS lead connected to the MPGuino. Last night the unit froze with a bunch of random numbers in all of the fields and the weather was pretty cold, so I doubt that was a heat problem in that case.

[dcb]

I might look into scheduled eprom saves for the tank trip and adding a watchdog timer. That way it should restart if it hangs and pick up from the last saved trip. Have to find a balance between eprom update frequency and eprom life (like 1,000,000 writes), maybe update every 1/10 of a gallon or so.

[nickdigger]

dcb, i posted up some save-tank code to the wiki Code Hacks page. If you only want the Save-tank, and not the Archive feature, it should be easy enough to weed it out.

(Also, i used the last "edit" on the page, and somehow it appended my hack onto the end of "Singletree's More Precision". Can you tell me how to fix it, so that ours are separate, and there is a new blank "edit" below mine?)

n/m. i got it. i needed the "== Hack ==" separator.

[dcb]

OK, will look into it.

Maybe update the eprom every mile, if this thing is still in your car after a million miles then I'll be impressed And if you lose part of a mile 3 times in a tank, of 300 miles, you are still pretty accurate on the tank trip.

[drbobwoolery]

Driving around town (potholes galore) I note that the reset, usually the current ? screen (the one that is three left button pushes from BIG INST, my preferred usual setting), about 1 time in 5 I noticed the ver .82 screen, and the changes always came at a jarring pothole. I wonder if bouncing around on the dash is actuating the pushbutton switches. The speed and gph readings in the multi variable screens seem stable. With the hard alkaline backup of power, and behavior consistent with stray switch closures, this seems the most likely explanation.

Are most of us with this problem driving on rough roads with shot shocks?

[steffen707]

i too have v.82 and mine acts weird like this. Freezing and having to unplug it to get it to function again. Mine is on a 97 honda civic. I tested all the connections, which are soldered and heat shrink tubed then taped. Wondering if its v.82 or something else.