Intermittently Losing Hall Trigger Signal

[fakename]

I removed the capacitor on pin 6 and it that seemed to solve most of my problems. Out of the circuit it had no continuity from one lead to the other. It did still reset a couple of times so I think I'll replace it with a new one. I know that these are band-aids rather than cures but even after all the research I've done, I'm not really sure what else to do as my grounds and power all seem to check out.

Any more suggestions are appreciated but I'd like to thank you guys for your help. I learned a little more about my circuit in the process.

[kjones6039]

Out of the circuit it had no continuity from one lead to the other.

Not surprising, depending on what scale you meter is set on.

Ken

[fakename]

Not surprising, depending on what scale you meter is set on.

Ken

Sorry but can you clarify, are you not surprised because that would imply that it's bad, or because that's consistent behavior for good capacitors? I was just going off google threads that said impedance should begin low and then climb to infinity if it's good.

[fakename]

Replaced the capacitor and I'm getting no resets, runs much smoother too. Can't find the source of the noise so this will have to do.

These updates are primarily for my own archiving but I'm still very open to any and all suggestions.

3.2.16: started missing past couple of days and today left me stranded. When it won't run, ecu is getting no trigger from hall sensor during cranking.

[fakename]

Car is not starting, I'm seeing trigger and spark leds on ecu during cranking, I get a weak intermittent spark holding plug wire from coil close to ground during cranking. I get no spark to plugs when it's back into distributor. Tested with different rotors/caps, I'm suspecting it's too weak overall. 12v to both sides of coil. Grounding tach in wire, voltage on negative terminal at coil drops to 3v and returns to 12v after a second or two, voltage on positive terminal drops to 9v then returns to 12v. Coil impedance is within spec, plug wires are too. Dwell is set at 6.0 crank, 2.5 run, 0.1 min. I've tested with 3.5 run with no change, not currently running...

Feels like whack-a-mole, this gremlin keeps popping up with different scenarios I'm wondering if it's processor problems.

Getting 12.5v on center pin of Q12 (batt voltage), getting 11.5v on left pin of U5

[fakename]

Any other suggestions to test? I'm drawing blanks here. Recap:

IRQtrigger and spark output leds flash during cranking with intermittent/weak spark direct from coil, no spark at spark plugs. Voltage in ecu checks out with the exception of 11.5v at left pin of U5 (is that normal?), coil/wires are within spec and coil fires when wired directly to battery. This has developed from my initial issue of having no hall signal to ecu which appears to be fixed.

I'm at the point where I might just start throwing parts at it but if I fix it like that, I'll still feel like I failed. i wouldn't even know what parts to throw! Everything tests in working order. Have a feeling my issue is somewhere in the ecu.

[slow_hemi6]

You can expect half a volt drop across D10, that is normal. What ignition module do you have driving the coil?

[fakename]

It's a bip373, ground is solid, 60kohms between tab and heatsink, pin 1 has continuity to pin 7 on the processor and resister inline is still good (330).

[fakename]

I've found this thread :http://www.msextra.com/forums/viewtopic ... 01&t=50833 about a firmware update not being compatible with a previous tune and showing inconsistent dwell times in TS compared to the ecu's code (?). I updated my firmware to 029y4 last week (don't remember what it was before) and am wondering if I may have a similar issue, low dwell time would be a cause for my symptoms. I can't figure out how to access the source code to see if I have a similar problem.

[fakename]

Issue resolved, it's twofold:

Firmware update did have an impact on my spark so I started a project from new and imported tables. This gave me a spark but was still very intermittent and weak.

Also, despite all my testing showing continuity and no shorts, I unsoldered, cleaned around, and reinstalled the bip373 and it sparked stronger than it has in a long time. Shocked the S*** out of myself when I accidentally ground my tachin while holding a plug wire.

Car is back on the road. Thanks everybody for all your help.

[fakename]

[slow_hemi6]

Good job.

[fakename]

Well, it drove great for about a week. Wouldn't start today trying to leave campus (after my last final exam as an undergraduate, I bombed it...), no trigger, no spark. Trying to clean around the contacts of the bip373 with a screwdriver, forgot I had the key on and shorted the center pin to the ground pin, then I tried turning it over and it fired right up. What?!? A few feet away it died again, no trigger/spark. Shorted those pins quickly and it fired up again. I made it home and have been messing with the bip since. That part of my circuit is has gotten pretty mangled (the metal inserts in the board for the center and ground pins came out) but I have each pin isolated as shown below. It fires up, but if I drive it, it will die. But short those pins and it fires up. Weird!

Questions:
1. What the hell?
2. Should the center 12v pin on the bip373 have continuity with the tab for the bip?
3. The bip doesn't get hot but could it's auto shutdown function be short circuiting and killing it? If the bip does shut itself down, would it keep my hall trigger led from flashing?

[slow_hemi6]

The answer to 2 is yes. The tab and pin2 are both the collector. I don't know what could be going on inside the BIP but shorting pin2 to ground is switching coil current around the BIP. Maybe try another BIP driver. Is the led the only thing not working? Is the 5v line crashing when you have the BIP issue?

[fakename]

I did order a new bip driver so that will be in the mail shortly, along with a jimstim kit, tired of running to and from my car to test this thing.
Not sure what you mean about the 5v line crashing, but I am seeing 5v to my hall sender.

I'm now getting spark/trigger leds but weak intermittent spark to my plugs (still won't start) just like it was doing before. I've got to assume there is a problem with the bip, particularly something like it isn't allowing enough dwell before it drives my coil, maybe? Don't know how though, that's the part I really want to figure out!

[slow_hemi6]

Yeah just asking if the bip was causing a problem with the 5v which it isn't going by your reply.

[fakename]

Last week I wrecked my bike on the freeway. Slammed into the back of a corvette and flew into the guard rail. Amazed that I'm still alive and appreciative for yet another chance at life. Plus, bike seems like it's still in good enough shape to make a pretty sweet streefighter. Who knows, I may go big-time and microsquirt a snail on it while I'm having fun...

Update on the car:

I replaced the bip and got a spark. Fingers crossed that it will continue. That part of my board is officially mangled though so I need leads wired directly from each pin of the bip to their respective circuits in order for it to work. Not a very pro looking board but I'm going for 'go' not 'show' so it's good enough for me.

It is my experience that the BIP373 is NOT indestructible as otherwise perceived to be. However, I also admit that my board may also have a ghost or two here and there affecting my results.

Thanks again to all those who lasted this long helping me with my anomalous spark issue. Cheers!

[fakename]

Issue continues. I'm bench testing it with the jimstim and was able to get rpm signal to the ms. Once I passed about 175 degrees with CLT I lost tach signal/rpm essentially recreating my problem. Now I can't get rpm signal back with the jimstim. But if I plug the ecu back into my harness and crank, it gives me signal. With the jimstim I have no voltage to the center pin on my bip but even when I jumper 12v to it (like it gets when plugged into my harness), I still get no rpms. I just can't figure it out, it worked a second ago with the stim, now doesn't work but works in the car? Any thoughts? Since my last post I tried a new CPU as well which didn't change my results.

Am I running the stim wrong? Pin 25 is my tach in, it sees 4.3V. I can ground pin 25 and get signal. Then jump it to the 'square wave' pin on the set of 3 primary tach pins but I can't get signal with the rpm pots.