4AGZE reset issues

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mhiscott
Helpful MS/Extra'er
Posts: 39
Joined: Mon Mar 27, 2006 11:04 am

4AGZE reset issues

Post by mhiscott »

I figured I'd post up the issue I'm having with my megasquirt resetting to see if anyone had any ideas on what could fix it. My setup is an ae101 4agze with modified cas (12-1) conditioned through lm1815 circuit running two vb921 coil drivers each driving an MSD GM dual tower coil pack. The engine is running pretty well now, and I've sorted out all my tach spikes I was having problems with earlier. Now, however, I'm getting resets under heavy acceleration. Mainly under boost at over 1/2 throttle. During these resets, the car will misfire and backfire super loud. Sometimes I even have to shut off the ignition and turn it back on to get the car to start again.
Anyways, I've got NGK resistor plugs, and I went through all my grounds when I was troubleshooting my tach spikes I had earlier this season. I decided I'd hook my multimeter up to the +12 and ground wires at my relay board to see if anything was up with the voltage when the car resets. I found that each time the car resets, the volt meter would go from ~14v or so down to "I" on the meter which means no readout avail, and then when the voltage would cut back in, it'd be higher than normal like 17v or so, then settle back to 14v. I decided to try a new alternator regulator, and it raised my charge voltage from 13v or so to 14v but didn't really have an impact on the resets.
I can't figure out what could be the problem with my power system to be causing these voltage drops on acceleration. I tried adding a voltage regulator thingy in line with the megasquirt's +12, one of those ones princess auto sells, but it made no difference. My power system consists of a redtop optima in the trunk, grounded in the trunk, and with the power wire (also 4 awg...maybe not thick enough) running to the front where the battery would normally connect. Perhaps something to do with the way the relocated battery is set up could be causing this. Any ideas?
mhiscott
Helpful MS/Extra'er
Posts: 39
Joined: Mon Mar 27, 2006 11:04 am

Post by mhiscott »

Oh, I forgot to mention, the car is a 92 corolla so the 4 awg wire running to the trunk is about 18-20 feet in length. Also, the MS is a v2.2 using the relay board and running 29q2
mhiscott
Helpful MS/Extra'er
Posts: 39
Joined: Mon Mar 27, 2006 11:04 am

Post by mhiscott »

Also, if the voltage is dropping outside of the megasquirt, can the ms/ignition system/etc be ruled out all together? I know my plug wires are a bit sketchy, but if the voltage is dropping before it gets to the relay board, it doesn't seem possible that plug wires or the like could be a contributing factor. Does it seem like this symptom would be caused soley by a bad electrical system regardless of how the standalone ecu is configured?
mhiscott
Helpful MS/Extra'er
Posts: 39
Joined: Mon Mar 27, 2006 11:04 am

Post by mhiscott »

Just an update, I upgraded the 4 gauge wire to 0 gauge (both power and ground) and there's no difference...
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