GODDAMNMOTHERFUCKINGSHIT. (I fixed my misfire)
 

I am so amazingly pissed off right now I'm temped to drive my car into the Pacific Ocean. :vash: :vash: :vash: :vash:

Since the initial install, I've been plagued by misfire under high load. Seems like it only happens when I'm in high boost- if I'm just accelerating slowly in 1st or 2nd I can take it to redline with no problems. So I don't know if it's rate of change of if it's really related to boost.

When it happens, the tach drops momentarily (tach is driven by the ignitor) and in the logs it registers as a seemingly random RPM value- sometimes a dip, sometimes a huge spike.

I've tried:
1- Upgrading to HR10G
2- Downgrading to 028y4
3- Replacing coils, wires, and plugs (gapped to .028")
4- Laying a .1uf car across JS8 and GND
5- Replacing said cap with a .47uf
6- Replacing the CMP input circuit with an optoisolator
7- Replacing both the CMP and CKP input circuits with a dual comparator circuit that Abe designed
8- Installing a 1k resistor between +12 and the black/white wire at position 2I of the stock harness

About the only thing I haven't done is install a PCPro...

[/rant]

Is nobody else having this problem?

I had the same issue until i gapped my plugs down to .025. Not sure if it is just the '99 coils or the BKR7E's i'm running but without gapping them down from .035-.028-.025 I was having issues.
I take it you don't have this issue when running the car to redline staying out of boost?
Are you running COPs yet?

Gap plugs to .020 and log it again, bet your problems disappear.

Throw your MSQ and a datalog into a zip file and post it... we'll take a look and see what we can see.

I had the same problem and it ended up being my ACCEL ENRICHMENT was kicking in and throwing an extra shit-ton of fuel. You could quick-like post a screenshot of you ACCEL ENRICHMENT PAGE4 in the BASIC SETTINGS window so I could rule it out.

I had this issue as well. Over time, I have done 3 things to try to address it, but didn't keep track of what helped, unfortunately. It's gone now though.

1.) Raised over boost protection a bit higher. I was getting brief boost spikes that put me close to the over boost I had input, which was causing issues. I now put over boost protection at ~5-8kPa above my peak anticipated boost.
2.) Ran an extra ground from the MS to the grounding point on the engine. This helped many issues, including noise in signals, and some misfires under rapid entry into boost
3.) Swapped stock plugs for the BKR7Es, but haven't seen a need for gapping them lower quote yet, as I'm only running 9psi.

I'd suggested pulling out the caps in the OEM circuit I'd posted, which I imagine will do the trick - but while for me it SEEMED boost dependant, I'm not sure it was.

That's a good point, I've had SO many problems which turned out to be accel enrichment which I thought was something else each of the times....

1) Yeah, though that's obvious from the logs. This isn't that, if it's what I've seen, since the tach will do funny things, the logs will do stuff like read 18,000 RPM
2) I did this two, tons of wire. Didn't help me, so I took it out.
3) I'm running 7's now. How would that help you, though??

Anyway, I had gapped mine small long ago when I doubted my coils, as usual, having 5 problems it wasn't obvious what fixed what, then.

When the toyo COP set up, I went back up to 0.35, and I have little doubt I could run 40 or 45 without issue, those things are amazing, even at 15 psi.

1) While if boost does cross the boost protection limit, it would be obvious. However, I saw odd things happen as I got close to the over boost limit, both while driving and in the log, including rpm drop-offs and spikes. I think I remember Jerry writing somewhere that the boost protection algorithm was in some way anticipatory, but I don't know more than that.
2) The later cars have more grounds to begin with. The 1.6 cars are sorely lacking, and can benefit from more grounds.
3)The 7's I run now are factory gapped slightly lower than the stock plugs, IIRC, which would help.

Did you try tweaking the coil dwell? Cranking 8 ms, running 5.5 ms?

Ok, lots and lots of ideas here...

1- It ain't accel fuel. First, I'm on TPS accel and second, accel fuel wouldn't cause my tach to drop out.

2- During the original install I ran two additional 16ga grounds direct to the head. Trust me, it's well-grounded.

3- Overboost... Interesting- I'll try disabling it.

4- Dwell- I've tried between 4.5 - 5.5ms running, no difference. (stock igniter and coils)

5- Plugs: Tried BKR7E at .035" and IFR8H at .028" with no difference. Again, a genuine misfire wouldn't affect the tach. I guess I can re-gap my 7Es to .02" before I re-install 'em.

6- Abe, I just nixed the capacitors, and will retry after I get HR code re-loaded.

Ain't it time for our hourly update?

Update: I started drinking with a very nice Barleywine Ale at about 4pm when I gave up for the day (just after you called me.) I continued drinking until I became drunk (there was some Porter, and then a couple IPAs), and then I drank some more. We're on Rum & Coke at the moment.

During this time I have removed the MS, desoldered the capacitors from the comparator circuit, resoldered the five other wires that accidentally popped off when I did that (hopefully in the same places). I then came inside and started going through my MSQ one screen at a time, making various adjustments like raising the overboost limit, going back to earlier, more conservative fuel and ignition maps (just in case) and making a few other tweaks that I've already forgotten but must have seemed logical at the time.

In other words, it will be a miracle if the car starts tomorrow morning.

If it does, we still on for around noon? That beer ain't gonna bottle itself, and I'm dying to taste how it came out. You guys already racked it into the secondary, right?

Ignore this post; I can't read.

Joe, please post your MSQ and a datalog. Without something to look at, we're all just guessing.

Yeah, sorry. I was debating which one to post, over the past few days I've been blowing through a lot of 'em.

Here's an example from the 11'th. This was after I built the opto-based second trigger circuit, I was running HR10f at the time. If you're wondering why the Spark1 table looks so strange, this one has map-switching enabled for the spark- this is a safety feature. When the WI system turns on, the pressure in the line switches the system to Spark2 which is more aggressive in boost.

The RPM spike at 461.5 is pretty obvious. There's another at 926.4, another at 1106.5, and some little ones from ~760 - 801.

I've done so many test drives the past few days I can't remember exactly where each tachometer dropout / misfire occurred. I ought to hook a button up to one of the inputs so I can hit it to insert a marker in the log every time something odd happens.

I used to get those spikes, and Mr. Hoffman advised that grounds needed to be beefed up. He was correct. We ended up running a couple more 18 (or was it 16?) gauge grounds from the MS' board to the back of the cylinder head. Fixed 'er up.

start hijack

That barleywine wouldn't happen to be the illustrious Gnarlywine, of Lagunitas Brewing Co., the barleywine of all barleywines, would it? Safeway has 24oz bottles for $3.19. A true gift from the Beer Gods. Maybe your swilling SN Bigfeet?

end hijack

Another member of the "slight misfire sometimes" club. I usually have a misfire to 0 RPMs on datalogs every 15minutes. I have found one thing oddly strange though. I can push a particular button on my car and the problem goes away. If I run the A/C, it will never misfire. Weirdest thing ever. Have no clue why and how but I guarantee it will occasionally misfire about every 15 minutes, but NEVER with A/C on.

No, I managed to snag a bottle of Stone Old Guardian a few weeks ago, and today seemed like the right time to crack it open. And now that I think about it, their 2008 Imperial Stout was just released- I need to get off my ass and track some down pronto!

But the one I'd really like to find, and call me fucking crazy, is an Oskar Blues Old Chub. A few years ago I was in Denver just after the big annual huzzah, and on the way to the airport I dropped by to see a friend who lives there. He took me to a place called the Falling Rock, where they had about two gallons left from the competition of what may be the most divine oak-casked Scottish Strong Ale I have ever consumed. It was one of OB's entries that year, and from what I can piece together it was essentially just off-the-shelf Old Chub that they aged for 18 months in a whiskey cask. Granted, I'll never experiance that particular beer again, but I'd like to at least see what their "regular" stuff is like.


Already done as part of the original install.

Yeah, you'd think that, but the MS works in mysterious ways. My car had the same issue (high-load misfires), and the tach would drop away (sometimes all the way to 0). Gapped the BKR7Es to .024 and the misfires are gone.

Update:

The coffee stout spent a total of three weeks in the primary and a week and a half in the secondary. Yesterday afternoon we bottled. Due to the fact that we failed to properly inspect the bottles prior to sanitizing them, we ended up with a large number of sanitized yet very yucky bottles, which fortunately we caught and set aside during the filling process. As a result, we ran out after 39 bottles and put the remainder into a 2 liter growler.

I forget what the final gravity was- Abe wrote it down, but I recall that it worked out to just over 5% expected ABV. We tasted the sample from the hydrometer tube, and despite what might have been called "questionable" sanitizing procedures during the initial brew (Abe, you have to *wash* your hands, with soap, to get all the Miata grease off before you dunk them in the solution) it was wonderful. Just a few more weeks to go as our beautiful little yeast perform their final duty.



Guess I should give an update on the car too...

Yesterday was much improved. I got the misfire only twice (out of a 50+ mile round trip).

Unfortunately, I changed about ten different things, and so I don't know what the fix was. I am hoping that it was the somewhat different cap values that I installed in the CMP/CKP pickup filter. I finally got off my ass and breadboarded that part of the circuit so I can swap values at will. There's something amazingly geeky about driving around with a protoboard taped to the floor of your car next to the case-less ECU with wires criss-crossing between the two. I'm going to try some different values this afternoon at lunch time, and see whether moving lower or higher makes a difference.

It still astounds me that people aren't screaming like hell about this sort of problem. I can't believe that every single one of you either hasn't experienced it, or was content to just fiddle around with random capacitors until it worked right.

Gonna be out of town tomorrow and Wednesday, so that leaves only today, and Thursday through Saturday to get this all figured out and put back into soldered form before the big run on Sunday. The dyno trip will have to wait- I'll be happy if my ECU is fully re-assembled in time. Guess I'll just have to turn down the boost a bit and run towards the rear of the pack...

I had pure hell for 3 weeks dealing with it, ask Abe. .020 gap helped a ton. Now I get a misfire every 15 minutes. However, it comes and goes with the weather it seems now a days. I "can't believe" after 2 or 3 people said to gap down your plugs, you didn't try that first.

I did. First try was gapping my set of IFR8Hs (which were on the shelf) down to about .028". That made no difference.

Yesterday, I gapped a spare set of BKR7Es down to .020" exactly. Not .019", not .021". (I've never in my life spent so much time dicking around with a set of plugs.) Unfortunately, I made several other changes at the same time, including some capacitor values. Anyhoo, with that setup I got the misfire twice yesterday, once on the way down to Abe's place, once on the way back.

The plan from here on out is to start "de-modifying" the setup, and see which factors if any affect it. I need to put my old (aka new) VE table- the one where I spoofed the "Req Fuel" number down to 3.5 to increase useful resolution in the VE table itself. Gonna do that at lunchtime, along with some larger caps in the filter- right now I've got .001uf on the CKP and .01 on the CMP. I wish I'd have made them both the same yesterday but I didn't have two of either value on hand... Gonna try .033 first probably, and I've got some .0005s on hand if it turns out I need to go down instead of up.

I would piss and moan about a missfire, if I had one anyway. I never deviated from the DIYautotune mods whatsoever. Wouldn't everyone be having this problem, including MSPNP owners if it was in the input circuits?

That's what is driving me absolutely batshit about this whole affair. I initially build the MS exactly to DIY specs, plus the .1uf capacitor across JS8 and GND.

After having the problem initially, I figured that the CMP signal being totally non-isolated (the CPU pin 11 going straight to the sensor itself) might be causing some issues. So I built a circuit using a opto-isolator (similar to the primary input) and replaced the "DIY" CMP circuit with it. No real improvement. For those who care, this was the circuit:
http://img137.imageshack.us/img137/1...circuityg8.gif


Then, I built a copy of the circuit Abe is using, which replaces both the CKP and CMP input circuits. This is what I built originally, the IC is a dual comparator, NTE943M (LM393):
http://img365.imageshack.us/img365/6419/abeszh3.gif

It still had the problem. Abe suggested removing the caps altogether, which made it far worse. I replaced C2 with a .01, and that seemed to help somewhat- gonna try upping both C1 and C2 a little and see what that does.

Let me ask you this- is your CAS an optical or hall-effect type? Mine, curiously, is a hall-effect sensor (I'd thought all the 1.6s had optical sensors) and I'm wondering if there's some correlation- ie: Are the Optical CAS's more stable for some reason?

I'm using a 94-97 magnetic type CAS. The 1.6s should all be optical. I think you can clean the internals of a 1.6 CAS, swear I read that somewhere.

I have had random misfires. Adding grounds took care of damn near all of them. I still get one occasionally, typically at high speed cruise. There does not seem to be any rhyme or reason to when, it's all completely random. The tach wiggles during the misfire event.

I don't have the cap filter installed. I was assuming that it would take care of the remaining, occasional misfires. But I haven't had one misfire since going to HR a couple days ago.

Yeah, that's what I thought. Last time I had the CAS out, I pulled the cover and inspected it. It's definitely a magnetic type. I wonder if there is some correlation here- could the optical sensors be cleaner somehow? (Anybody got an optical CAS they wanna loan me?)

Well, mine definitely are not random. It never happens in cruise, only in boost. I cannot for the life of me figure out how this makes a difference. And when it happens, my tach needle doesn't just wiggle, it drops like a stone. I honestly did not know the needle could move that fast!

I've been running HR since the beginning. Started at 10d2, ran 10F for a while, and now I'm at 10G. A few days ago I installed 029y4, and it made no difference whatsoever. That reminds me, time to update the sig.

No you didn't. You said you run .028 in your first post. Then patsmx5, cjernigan, and Savington suggested running less gap and that in all 3 cases it helped with their random misfires.

In the post I quoted and shortened above, you now say you tried .020, along with several other mods and the situation improved:eek5:, but you can't pinpoint what helped because you changed several variables at once. So indeed you did not(try gapping to .020 first).

Ok, you win. I'm an idiot.

I'm not arguing with you- seriously. I just can't get my head around how too large of a plug gap can cause the MS to think I'm spiking to 43,000 RPM for one sample...

Sorry, just been feeling really frustrated with all this. Believe me, I will ultimately take the time to go through each variable one by one- I'm just feeling really pressed for time right now as I *need* this to be working perfectly by Sunday. I've spent too much time slacking off and not addressing the problem, and it's now biting me on the ass. :mad:

2 minute explanation: Suppose you ran .100 gap. It would be hell on the coils. They use more power and sink more heat. It would put more strain on the output circuits of MS. (I think, Abe or someone smart confirm/deny this). Gotta go to Cal3.

one acronym: cops.

Shouldn't. Inside the igniter, the output of the MS drives the gate of a FET. The drain/source junction is what carries the load of the primary coil winding.

Besides, the primary current should, in theory, be purely a function of dwell time, without any regard whatsoever for what's happening on the secondary winding.

I failed miserably at my first attempt to build a COP setup. Just couldn't get the damn things to spark. If anybody has four known-working COPS they want to sell me, with a guarantee, I will pay you $100 for the set. I'm tired of the eBay crapshoot.

Joe, if you're getting insane RPM spike readings, it's not grounding, gaps, or filters. That's the ignitor on its way out. The symptoms of a failing ignitor include misfires with tach drop out.

If you want to send me your COPs, I'll run them in my car for a while.


Ben

First, an update:


:yippee:


Today at lunchtime I replaced C1 and C2 with .033uf, turned up the boost, and went for a drive. Made a solid 180-185kPa (with onset over-shoot to 203) and not a single misfire!

Gotta do some more driving to really convince myself that we're solid, but this is the first time I can recall it not giving me a single misfire- I'm really leaning towards calling this one resolved. There is much rejoicing.

I believe tonight I shall re-install my IFR8H plugs, set to .030", and see what, if anything, that does.

I was going to throw them in the trash anyway, so PM me your address. Unfortunately, not having the proper connectors I first soldered directly to the pins and then, like a total idiot, assumed that everything was perfect and poured epoxy into the shells before actually testing them. Still want 'em? :cool:

I've got a spare igniter shell, maybe I'll try building one. Should be just a couple of N-channel FETs...


I'm serious, though. $100 for a set of COPs with the caveat that the seller guarantees me they will work when properly installed.

Yea, I started to say your caps were huge.(probably should have, but I got off on a tangent about plug gap instead.) I run a 1 pico farad. I did run a 1 micro farad per Abe's suggestion, but had bad misfires. While back Abe argued with others on a ms forum that .1 micro wasn't too big, but now he say's they are.

Damnit, I keep forgetting the glue thing. Nonetheless, bring them over - and I'll knock them into mine, with aligator clips if I have to. Make sure they work and work well. My feeling is the odds are really low there's something wrong with your coils. It took me forever to get my wiring sorted, and I've seen other people have similar issues.

And for the love of god, don't run a 030 gap! You're only making it worse, and you ARE damaging the coils the harder they have to work (though not the MS). The 0.4 hp you'll get out of a bigger gap isn't worth one misfire per pull or a shorter lifetime. Small gap, work on COPs, drink beer.


Two things, 1) Yes, I think it's too big! Live and learn. Two you're in a parallel set up, so you already have a werid filter on your signal (through truthfully not that big a deal, it's there. 3) If I were you, I'd try 10 pf. Or 2.2.

I'm just having a hard time getting my head wrapped around the idea that a bunch of people are apparently very happy with the .1uf cap between JS8 and GND (ok, the resistors in that scenario are very different, but it's still .1uf) and that he's now very happy with no caps at all. With no caps, mine barely ran at all (it was misfiring at idle) and with .001uf before that, I had pretty regular misfires under boost.

Yesterday I put a .01 in C2 (CMP) and that seemed to improve things somewhat, then today I put .033uf in both C1 and C2 and didn't get a single skip.

This evening on the drive home I'm going to try .0047 in both positions and see what that does. I've also got some .0088s, some .001s and some .022s to try.

Well, first of all I'm running MS II with stock 99 sensors. I tried running about 20 (no joke) different input circuits Abe thought would work. I later find out he didn't actually run them, but they were all variations of what he used, and he thought they would work or be better in some way. After 2 weeks I talked to Arga and he sent me a very simple schematic of his input circuits. I've been running them since.

I am a very happy panda.
 

I believe we have success. Perhaps a title change would be in order. :D

This evening before leaving work I removed the .033uf caps and installed .0047uf in C1 and C2. These are the J-code high precision ones, no more ceramic disc -20/+80 BS. Took the very long way home, hammered the piss out of it again and again (175-180 kPa all the way to seven grand up some long hills) and it was simply perfect- not so much as a hiccup and no log abnormalities.

In the interest of being perfectly scientific, I stopped about a mile short of home and replaced the .0047s with a pair of .00047uf caps, keeping in mind that I originally had trouble with .001s when I first built the current input circuit last week. As expected, I hit a hard misfire between 4000-5000 RPM every single time I got into boost, and the log claims that I peaked at around 32,000 RPM.

Didn't have any .0022 or .0033uf caps with me, but tomorrow just for kicks I may try to find a pair and run them at lunchtime to see what happens. Or I may not- I'm actually very happy with I've got now, and having a comfortable margin away from my closest known failure point (.001uf) pleases me.

While the .00047uf caps were in, I also made sure to make a few runs past the "misfire window" while not in boost, and I didn't have a failure. So there's no question that whatever is happening is somehow related to being in boost. That above all else has been driving me nuts, and I finally had an idea that may explain it.

We're all familiar with the tendency of inductive devices to create a big voltage spike when they are de-energized, right? I mean, that's how ignition coils work. Well, what the heck are fuel injectors, then? They are really big inductive devices, wired in parallel, and connected directly to the MegaSquirt

Think about it- if you want a "hotter" spark out of your coils, you increase the dwell time. Well, how do you get a bigger kickback out of your injectors? Increase the "on" time. And that, for any given RPM, is the primary difference between boost and not-boost. Yes, there is a clamping circuit, but all that power still had to travel through the harness and halfway across the PCA in order to get clamped in the first place. 4000 RPM at 60kPa = ~3ms, but 4000 RPM at 160 kPa = ~9ms. More dwell time!


patsmx5, I'd be curious to see the circuit you ended up with. I suspect there are a lot of running around very happy with undocumented mods.

Can't find the schematic. I have it somewhere. I know it's on this computer, but it's hiding. I'll send it to ya or post it when I find it.

psst joe: capacitors in series?

C = 1 / ( 1/C1 + 1/C2 + 1/C3 ... 1/Cn )

so did you like stop on the road and bust out a soldering iron to change the caps on C1 and C2?

Unfortunately I wasn't carrying an entire sample kit with me, just a few pairs of different values in a bag. All I had on-hand at the time were two each of .0047, .00047, .033 and .001.

edit: Actually, I take that back. I also had a pair of .0082 on hand, since I was half expecting the .0047s to fail. Well, I'll stick 'em in tomorrow morning before I drive to work and have an equivalent .003uf

No. After asking myself "What would Chuck Norris do?" I focused the intense power of my mind onto the circuit and the solder melted out of fear.

:jerkit:In other words:

http://img178.imageshack.us/img178/8273/protoqx0.gif



On a more serious, I gotta say a big thanks to Abe for taking the time to reverse-engineer the Mazda OEM input circuits, sharing them, and then hounding my ass until I actually fixed the problem.



BTW, patsmx5, the reason I was being so stubborn about the plug gap is that I ran .030" for a very long time with my EMU and never had ignition issues.

that is neat. NB owners dont have that nice wide space to do things like that

And there is much happiness.
 

Drove to work this morning with an equivalent .003uf on C1 and C2 (.0047 + .0082) and it felt fine. I compared this morning's log with yesterday afternoon's, and it seems like the .003 gave me just a tiny bit more "jitter" in the RPM readout than the .0047 did. So with that piece of data in hand, I've settled on the .0047 and will be permanently installing them and closing up the MS for what might hopefully be the last time for a while.

Thanks for the suggestions everyone, and I do sincerely apologize for being a bit of a dick the past few days.

Honestly- the ECU in the NB is in such a horrible location that I cannot see why you fixed-headlight guys don't all relocate it to the pax side. I can't imagine having to crawl up under the steering column every time I wanted to touch the box- hell, one of my MAP sensors is up there, and even that little thing is a horrible pain in the ass to reach.

I've considered relocating it, just use a 4-6' DB37 and move the MS over to the passenger side. That would require effort though.

Joe, have you sent out your COPs to Ben to test yet? ;)

you know, i might JUST do that. my foot sometimes hits it while it hangs attached to the stock ECU. ill hit frys later today.

i too have been having some misfiring issues (check engine light has been coming on with P0172 (system too rich) and P0300 or P0301 (misfiring), im thinking this might help the problem. ill try out what you have there, using the 0.0047µf, il let you know how it fares on the NB. after tomorrow's exam, im going to also try to increase the amount of grounds coming from the DB harness, hopefully that might solve some problems.

that means i gotta reroute the vac line, hah, more work. oh well.

Still waiting for a PM from him with his address.

Sounds like a plan. The '94-'97 guys really got lucky with their ECU placement. I wish Mazda would have done them all like that...

It doesn't look like a lot on paper, but that darn comparator circuit winds up being a whole lot of parts. I managed to fit mine (barely) into the proto area, where it consumes about 2/3 of the space, leaving just enough room for two relay drivers and a pair of resistors related to another hack.

Euro-spec NB for the win! :)

Jim

Sorry Joe, I thought you wanted to go a different route. PM forthcoming.

Nice install- looks very clean. What is the amazingly large thing to the left of the MS?

[edit] Greece... Left-hand-drive country... Didn't know the LHD Euro NB's had a different wiring harness. Interesting.

hmm, ill look more into it for sure.

Joe. This thread here: https://www.miataturbo.net/forum/sho...hlight=ms+2004 highlights his build. That is a switch box for his parallel wired MSI.

OMG! If anyone does this, I want to know how it works. I have SERIOUS doubts that an off the shelf parallel cable will deal with 15 amps of low ohm injectors running through it! I've thought about it and rejected it on principle several times.

Also, it's not just swapping in a cap into any circuit, it's the combination of caps and a good comparator which does it. Like Pat's set up, you can't just take parts from one circuit and put them in another.


Joe,
Yes I too noticed that there's more jitter (on the scope) with big caps. Ideally you run the smallest caps which never EVER let any noise through. If they are two big the motor won't run above certain RPM.

I'm still really curious why you needed such large ones, I'd love to see your car on the scope. Pulling out the caps entirely and idling in the garage might tell a nice story. Obviously your sensor is very different from my VR ones.

I guess we just work in different industries, but I just don't consider 0.0047uf to be a huge cap. I mean, the "fundamental" frequency of the CKP pulse, at redline, is 240 Hz.

When I ran without any caps at all, it misfired just revving it in neutral.

However, the caps have been soldered in, the case is closed, and there will be no probing.
From the ECUs point of view, your sensor is same as mine. They both contain an active driver with an open-collector output.

But, mine hates me. And yours doesn't hate me. It hates you. :-)

Too bad about the probing, I like probing. You need to mount the MS somewhere easier to get to it, perhaps your forehead.

I should strongly consider sleeping longer at night.

High Load misfire especially under rapid throttle input is generally due to inadequate spark. Basically high cylinder pressure combined with a lean mixture and you get a resisitant too high for the spark to jump, thus the "0" on the tach log, as you got no spark.

Assuming this a 89-97, I strongly suggest running Nology Wires and NON resistor plugs. You will get static on the radio, but who listens to AM anyway?
Adding the Nology Coil amplifiers will also make a difference if you want to run serious boost and are having spark blow out problems.

http://www.nology.com/images/sparkdiag.gif

Doc, see the section you are posting in...it's specially related to his Engine Management.

Ok, thanks for the advice, Doc. :jerkit:


And it turns out that I fail again. I swear that it was working fine earlier this week when I had the breadboard on the floor. I re-assembled the unit, mounting those exact same two capacitors back in the proto area, closed up the case and re-mounted it, and it's doing it again... :vash:

This is really starting to get ridiculous.

I think I'm going to just say "fuck it" at this point and install a pair of .022uf caps. It was working with .033uf on the protoboard, so I know those aren't "too big", and I really just need this thing to be running properly for Sunday.


:ky:

Yeah, I envy the '94-'97 crowd in this regard...