BIP knocks MS1 silly

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AGDrake57
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BIP knocks MS1 silly

Post by AGDrake57 »

Using MS1 version 2.2 pcb, I ran my jaguar with small block chevy TPI for several years, in next cylinder mode, with HEI 8 triggering MSD spark amplifier.

I recently rotated VR pickup coil backing plate 30 distributor degrees in advance, to give tach pulse at 60 BTDC, and installed BIP 373, triggered by squirt LED, using BIP 373 kit, with 330 ohm base resistor.

Using megastim, I got it configured, and emitting spark, though not before running some minutes with spark output not inverted - coil was warm to touch. At any rate, spark seemed consistent and reliable.

When installing, I acidentally reversed polarity to BIP373 ( connected coil plus to ground, connect ground to BIP373 to +12). In this configuration, BIP triggered coil directly. After fixing reverse polarity, car would start, but barely.

Next, I tried moving BIP373 signal from coil minus terminal to trigger MSD6a spark amp, and it runs quite nicely.

So, back to bench, to investigate. Triggering coil directly results in erratic running on megasquirt for a few seconds, then all pulsing ceases.

During checking this process, somehow code got clobbered, and was necessary to load 29Y4. After loading 29Y4, pulsing with stim all looks good, TS instruments work nicely, etc, if and only if BIP373 coil triggering disconnected.

I can start MS with stim, it runs pretty as you please, then connect BIP373 base signal, coil begins to emit, then MS1 runs in fits and starts, then pulsing stops, until MS power is removed and restored.

Bottom line is, direct coil triggering seems to knock MS1 silly. Is this familiar to anyone?

Thanks, Drake

Thanks, Drake.
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Re: BIP knocks MS1 silly

Post by Matt Cramer »

Try redoing the BIP373 grounding so the left leg ground is routed out of the board and to the block or head.
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AGDrake57
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Re: BIP knocks MS1 silly

Post by AGDrake57 »

bip 373 is mounted inside top case, squirt signal is inside case, ground and coil minus leads extend an inch or two from BIP373, then are strain relief and routed outside case, twisted together.

The goals of this rework are:

1) To get away from next cylinder mode, which is accomplished, and
2) To get away from MSD6A spark amplifier, which is so far, elusive.

When I first ran w Single Coil Driver (SCD) triggering (trigger bip373 w/squirt signal), spark was consistent, pulse timing good, I ran it for 10 minutes or so with megastim, all good.

Now, with SCD coil triggering, spark and fuel pulsing is erratic, then ceases after a few seconds. This is after temporary reverse polarity to SCD during installation.

With proper polarity, there is no DC voltage present at the base signal to bip373, triggering by hand (disconnecting base signal fr ECU, momentarily touching SCD base signal to +5 w causes coil to emit, so from that respect, SCD seems good. I can start MS with stim, injector pulses are good, then touch SCD base signal to squirt signal, and it misfires, and crashes.

Thanks, and have a good weekend!
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Re: BIP knocks MS1 silly

Post by AGDrake57 »

The plot thickens -

I had really inconsistent results, after loading 29y4 - Tuner studio converted and burned settings, settings that were saved from 29q configuration. As mentioned, I ran 29q for several years, but it seemed to get clobbered when running on bench with megastim and BIP373, with coil, on bench.

So, TS seemed to convert and reload output settings, spark settings, etc.

Car did start, but seemed waayy rich, I had to cut fuel back to about 1/3 of calculated basic fuel setting, then had trouble getting it to start and run consistently. I played with fuel, spark, etc, and at times would run, at times would not.

All output and settings look correct, and at times car seems to run decently, but next try it won't, it just seems flaky.

The last configuration that ran consistently well was 29q. I've looked, but did not find a download.

Is there any reason 29y4 won't do everything that 29q did, if not better?

I'm beginning to wonder if I've damaged my processor chip, or BIP373. As mentioned, I cannot run system with BIP373 firing coil, which I was able to do before reverse polarity.

Thanks again for any thoughts.
AGDrake57
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Re: BIP knocks MS1 silly

Post by AGDrake57 »

Well, most of latest round of difficulty was due to my allowing Tuner Studio to attempt to reload settings saved to laptop, after loading version 29Y4. Settings were saved when ECU was running version 29Q.

When I reloaded 29Y4 and declined to allow TS to reload offline saved settings, things got much better in a hurry. Most of 29Y4 defaults are close for my setup, really only had to tweak required fuel and TPS calibration, and it started and ran nicely.

I have not again attempted to run with BIP373 driving coil, as it is, BIP373 triggers MSD6A. So things are looking up.
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Re: BIP knocks MS1 silly

Post by dragbug »

Just so I can understand, are you saying that some of the problem went away when you loaded default settings instead of your saved settings? I have been having some odd issues with the BIP driver and how my injection is working. So far I have not really had a chance to determine if its a hardware issue or a software issue. I have been thinking about just loading default settings for my current firmware version and manually input settings correct for my application. That sounds like what you have done and it worked?
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AGDrake57
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Re: BIP knocks MS1 silly

Post by AGDrake57 »

That's just about the size of it.

I think I also damaged my MS1 cpu, when I accidentally connected BIP373 coil positive to ground, and BIP373 ground with to +12 volts, with BIP373 base connected to squirt- signal, which is a net (conductive trace) directly to CPU.

Before I did the reverse polarity, my MS1 drove BIP373/coil, pretty as you please. After the reverse polarity incident, MS1 staggers when attempting to drive BIP373/coil, car will run, but barely.

Using the BIP373 to trigger MSD6A spark box, car ran fine, even after reverse polarity, but I somehow clobbered the code attempting to run BIP373/coil on bench, which necessitated loading version 29Y4.

I had tuned with MS tuner, while running version 29Q. After loading version 29Y4, I allowed tuner studio to restore 29Q saved settings, and this was a *VERY BAD IDEA*. It *WILL NOT WORK*! Tuner studio seems to do a block copy of settings, apparently the memory map is different between the two versions.

The car would sometimes start, sometimes not, I tried all sorts of different settings, it was totally hit or miss, just really flaky.

I then reloaded Version 29Y4, which starts out with default settings, then created a new TS project, and modified 29Y4 default settings for my installation.

29Y4 default settings seem to be for a V8 in same cylinder mode, with 60 BTDC (30 degrees at distributor) trigger angle, all set up for single coil driver like BIP373. I don't think I had to modify ignition settings at all. As mentioned, I'm triggering MSD6A white wire with the coil minus lead from BIP373 - this signal looks just like what points would, with the exception of more consistent dwell.

I think if I had not damaged my CPU, I could drive coil directly with BIP373. Before the reverse incident, using megastim, I fired coil directly w BIP373, ran it for 15 or 20 minutes, no problem, after a while I got tired of listening to the sound of the spark. Now, if I try the same thing, it runs fine until connecting squirt signal to BIP373, then it staggers and crashes within a second or two.

So, yes, just starting with version 29Y4 default settings, the car went from barely running, to a nicely running configuration.

The car runs nicely now, much the same as it did all those years with version 29Q. I ordered replacement CPU today. 'Hope this helps!
dragbug
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Re: BIP knocks MS1 silly

Post by dragbug »

Thank you! I might try totally starting over with the project and settings once I get my COP wired in.
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AGDrake57
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Re: BIP knocks MS1 silly

Post by AGDrake57 »

Well it turns out that BIP373 mounting tab was shorted or arcing to Megasquirt 1 case when coil emits - while testing BIP373 on MS1 setup for another car, I noticed that playing with the spark gap could knock MS1 silly - a very close gap seemed to resonate badly. In automotive coils, secondary and primary are connected at coil minus terminal, there's a 300 volt or greater spike on BIP373 mounting tab when coil emits.

Also while testing I found that it is very easy to short mounting tab to MS1 case. When mounting BIP373 to case it is *critical* that:
1) Diameter of hole for mounting screw be just greater than plastic insulating shoulder washer that comes with mounting kit; and
2) Mounting hole *must* be deburred using either a countersink, or larger drill bit, then finished with emery cloth;
3) Screw hole in mica insulator must be centered over shoulder washer - shoulder washer is deep enough to protrude through tab, this is by design to keep mica mounting hole perfectly centered. To do this, get nut started, and run down close, but not tight, then fine tune insulator position to center, then tighten, but not overtighten.

If you do not observe these practices, you are asking for headaches, flakiness, and unreliability. Please ask questions, if this is not clear.

Heat sinking BIP373 is mandatory, during high RPM testing I drove BIP373 that was in free air (not mounted, just hanging by wires) to overheat shutdown, melted a scope probe clip. Mounting BIP373 to Megasquirt case is well sufficient, *provided* insulation/isolation is proper.

So after paying careful attention to BIP373 insulating mounting, my MS1 with BIP373 is sparking happily, I've run this setup on bench for hours.
dontz125
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Re: BIP knocks MS1 silly

Post by dontz125 »

If you're experiencing thermal shutdown / melting of scope probes, you're overdwelling your coils. The guys at DIY have run torture tests, and for most 'civilised' coils and dwells, the BIP gets warm, not melting-things hot.
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AGDrake57
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Re: BIP knocks MS1 silly

Post by AGDrake57 »

You must not have read the part where I mentioned the chip was in free air, not heat sinked. Dwell is set to 1.5 ms, this is not out of order. Also this was at high rpm, the chip is active much more often than at low rpm. It matters.

When chip is heat sinked, by mounting to the case, it is only slightly warm to the touch, not an issue. After running an hour, the coil itself is only slightly warm.

The only point in saying so is that heat sinking BIP373 (mounting to case is fine) is not optional. Ask the DIY guys if you don't believe me.
DaveEFI
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Re: BIP knocks MS1 silly

Post by DaveEFI »

The shoulder on the mounting bush as supplied with BIP kits is a bit marginal in length IMHO, so does need careful fitting. Longer ones are easily available, though.

However, I always check for shorts after fitting any insulation kit.
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AGDrake57
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Re: BIP knocks MS1 silly

Post by AGDrake57 »

DaveEFI wrote:'''...However, I always check for shorts after fitting any insulation kit.
Yep, lesson learned here. The informative part of this little waltz is, with the mica and shoulder washer misaligend, at testing voltage levels, BIP373 was not shorted, but at running levels it arcs, and the arcing is what knocks MSnS 1 into the weeds. So anyone fitting BIP373 to MS beware! Take extra care to be sure shoulder washer properly aligns mica, or you will regret it. In my case it took a fair bit of trial and error to sort out what was wrong, and a BIP373 was damaged. So, I live and learn, and hope anyone else may benefit.
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