AustrianVespaGuy

Lol, this all sounds surprisingly familiar, albeit a decade removed in the specific technology involved. . . but still, !

Not that it probably matters at this point as you already seem rather pot-committed, but instead of running Tuner Studio in the car all the time, I use the mobile version Shadow Dash for monitoring and datalogging, and then I can run the autotune in TS on a captured datalog at my desk (instead of on-the-fly) so that I can get a better idea of exactly what (and why) autotune wants to change before I actually implement it.  This mostly helps me keep the tables 'smoothed' from box to box, as the autotune sometimes yields pretty big jumps between adjacent cells.  Just FYI.

http://www.tunerstudio.com/index.php/shadowdashmsmenu

Aww, but it was all ready to roll for Megasquirt with the 02Again trigger wheel and EDIS! Call the guy back and say you want the MS box after all! JK, I'm sure you'll be equally happy (albiet poorer) with a Haltech too.  Good luck with the new high pressure install!!!

Hey glad to hear you've made some good progress on getting things running correctly!  Hope your starting to have fun with things and can't wait to see how the next datalog looks!

9 hours ago, Dudeland said:

I can keep it in open loop based on temp, fuel, TPS, RPM and a couple others.  I am currently using RPM and keeping it at about 1050 RPM.   I am going to let it learn and see where the tune is headed, I can live with the rest, but the stumbling and stalling when coming down to idle is going to be the deal killer. 

Does it still stumble/stall even when you have it switch to open loop at >1000 RPM? If so I would say the next experiment should be to go to open loop at low (<5% maybe) TPS instead, meaning it would kick in sooner, as soon as you close the throttle, and see if that is at all different or still the same.

8 hours ago, Dudeland said:

To answer your question, yes it was working fine, I have talked to some local dyno owners and the problem may be that rpm is getting out of sync with the EFI.  The crank trigger would solve that because the method of sync is much more rigid. 

So on this topic: yes and no - let me explain

A crank trigger would indeed be make the timing signal much more accurate, which would indeed be just what you want to have if Sniper is controlling the spark timing for the ignition.

However, it would NOT make the RPM signal any better.  You can see from the datalog you have a nice clean and accurate RPM signal, and 100 ignition events per second is still 3000 RPM, regardless of whether those 100 ignition events happen at TDC or 50 degrees BTDC.  (100events * 2revs/event * 60s/min / 4 plugs = 3000 revs/min). We're not talking direct injection here, so the timing of the injectors squirting fuel into the manifold is essentially irrelevant; it's only frequency of the injections and amount of fuel that are important.  Timing isn't even that important for port injection engines for that matter; as cool as sequential injection sounds, it's mostly about economy and emissions, as at peak torque/power RPMs the injectors generally need to be squirting longer than the length of time the valve is even open, see here: https://www.diyautotune.com/support/faq/megasquirt-tech/sequential/

So what I'm saying is: don't think the trigger wheel will help you at all with fueling, because it won't.  But still do it for ignition control, whenever you decide you want to tackle that, because that's where it WILL make a difference.

I hope this is helpful stuff for you; I realize sometimes my explanations can get a little long winded, but I really do think all your problems are solvable but I want to make sure you try to keep things simple so you don't get sidetracked chasing the wrong ghosts!

Ok, looked over the datalogs and my theory is that this issue is basically due to the Sniper injector(s) being too big for your M10.  When you're in open loop and have it idling OK you're running way, way down at ~1.6ms pulse widths and 1.5% duty cycle.  I don't know the resolution of Sniper's injectors or controllers, but my guess is that when you try to go closed loop the 'smallest' correction that it can make a relatively HUGE difference in fuel for your engine, e.g. 0.2ms is a 13% change in fueling amount.

Here's some good general reading from the Megasquirt side on this stuff if you're interested:

http://www.megamanual.com/v22manual/mtune.htm#idlepw

But the good news is, that if you can figure out how to keep it in open loop (at least at idle), seems like that will still work alright! Consider doing a good bit of driving around and datalogging so that you can get to the point where things are 'pretty good' in all driving conditions, and then just lock everything down and leave it all in open loop, and then you can still go back and manually tweak specific areas as needed.  Closed loop really isn't all it's cracked up to be; once warmed up, the inside of your engine doesn't change much.  The right amount of fuel for 75% throttle at 2850 RPM will be the same next year as it is today.  Then there's problems like a malfunctioning O2 sensor that can then make a good running engine into a poor one very quickly and leave you wondering what the hell happened.  On my Megasquirt cars I leave O2 feedback correction limited to 1-2%, mainly so that I can see in the datalogs when it "thinks" it needs to adjust fueling, 

One other idea, what fuel pressure are you running at? If you can dial down the fuel pressure some, it would obviously help this situation, as you would then require *longer* injector open times to flow the same about of fuel.

A final observation, can you confirm what your 123 advance curve look like right now?  What I'm seeing in the log looks awfully aggressive, with jumping up what I'm guessing is full advance of 36 deg. by about 1500 RPM.  While I don't think is is really the cause of your issues, if it's really that abrupt it's probably not right nor that helpful here either. . .

Your 123 was working before the Holly install, right? I would not recommend throwing another system full of new variables in to the loop right now until we understand and hopefully solve the issues with what you have first. I'm generally in favor of doing the crack triggered route, I just think we should get things dialed in first as I'm not yet convinced timing is really your problem. Let me review the logs and such and get back to you later today.

Where did you install it in the header? I think that Bosch LSU4.2 sensors don't like TOO much heat; I was killing about 1 a year in my car so put in one of these to help the situation; only been about a year so a little premature to tell but have a good feeling about it! NOTE: note sure if this issue also applies to the new LSU4.9 sensors too or not. . .

https://www.innovatemotorsports.com/xcart/product.php?productid=16148

Convention is 24" downstream from the exhaust ports.  You want it far enough away that gasses from all 4 cylinders have mingled and the EGT isn't so hot to foul the sensor, but not so far away that it takes forever to warm up and lags behind what is actually happening in the combustion chamber.  In all honesty though, I think a lot of this is more important for turbo and catalytic converter setups, and doubt a few inches closer or further will make much difference in the M10 exhaust stream.

Correction, if you cut fuel completely, then you don't burble either, sorry!  And timing also matters some, but I'm less clear on the relationship there.

You can go pretty lean on overrun (15-30 kPa area), but if to go really lean, say higher than about 15 AFR, you'll get a lot of exhaust 'burbble.' Some people like this sound, so if you do aim for 16-17 AFR, or if it's not your thing, more like stoch - 15.

Ray has a point, if the system is still learning and shooting for a target AFR at idle, then yes the exhaust leak could be screwing with that a bit. Obviously something you want to fix anyway, so no reason to wait on that repair

Unless you have stupid high compression 8-10 sounds low to me. My experience is that M10s like a fair amount of advance, and for me that is mid-teens at idle up to high 30s or even 40 degrees all-in.

Neither intake nor exhaust leak sold cause a speed density EFI to hunt at idle, much more likely is either the ignition advance or fuel map being slightly inconsistent in the idle area, so make sure those are both very smooth/constant at idle RPM and MAP. I even like to put the idle advance in a little 'valley' to help steady it, aka 18 deg below idle (500rpm) 16 deg all around idle (600-1000) and then climb back up to 18 at 1100 of idle.

While your in there, might be with pulling a bearing cap to plastigauge the crank bearing clearance if your problem is oil pressure. . .

That guy's me, so thanks but yes I'll stand by those values for AFR targets!

Well I think the AFR response looks smoother than the first datalog, so must be making some progress!  Your target AFR band seems pretty narrow though, never going leaner than 12.3, and you really want to be leaner on overrun and part throttle cruising, more like 14-15 in those areas.  But aside from timing, things look pretty good under high MAP acceleration.  AFR still seems a bit noisy in transient areas (throttle opening or closing quickly); do you know if the the Sniper is supposed to be able to 'learn' those acceleration enrichment portions also or does that need to be more manually configured somewhere?

Good stuff, I'll check out your log when I'm home this evening and we'll see how things look!

6 hours ago, Dudeland said:

So the 123 is setting the timing.  It triggers the MSD,  then the MSD sends a signal to the sniper.  My voltage was dropping well below the limit for the MSD,  I don't fully understand why, but when the voltage to the MSD drops they get super wonky. 

Ok great, in that case, once you have the alternator voltage stuff sorted out, check things with a timing light to see where you actually are at idle and then compare those results to what you see in the datalogs.

Ok, so reread things, and sadly it seems that the Sniper units cannot accept a toothed wheel input for crank signal and then directly control a coil.  I suspect this is because they're trying to get most people to pop for their dual sync distributor, and that's fine for most of their customers with 'Merican engines, but it's not quite optimal either.  The drawback is that it all cases, it takes the crank signal from the distributor (not the actual crankshaft), which means that any lash/tolerance in the whole valve train (timing chain stretch, sprocket wear, cam to dizzy gear lash, etc.) causes some inaccuracy.  In any case, for someone with a basically stock M10 ignition I'd recommend the MSD route with locking down the dizzy and letting Sniper control the timing.  However since you already HAVE the 123, you don't really have much to gain from this and instead I'd say just use the MSD to send the RPM signal out to Sniper but let the 123 continue to actually control timing (page 24, the Ignition Box Tach Output - No Timing Control setup).  You get to program you own advance curve either way, but having the Sniper do it would be a 'longer' chain (123 - MSD - Sniper - MSD - Coil vs. 123 - MSD - Coil) which just gives more possibilities for error, at least the way I see it.

@Holley Tech, please feel free to correct me if any of my understanding/assumptions are incorrect, and I'll just say I think it would be worth considering adding crank wheel input and direct coil control options in future versions! Granted I'm a biased fan of wasted spark setups, but I'm sure I'm not the only one!

So what is actually controlling timing then, the 123 or the Sniper ECU? Clearly the Sniper *thinks* the timing is dropping to zero, but we need to figure out if it ACTUALLY is.  If sniper is commanding the timing, then it probably is, and we need to fix it in the tune.  However if the 123 is controlling the timing and just sending the signal to the Sniper, then it's more likely an issue with the signal.  Either way, I would suggest you break out the old fashioned timing light and see if you can compare actual timing (with the light) against the logged timing.  While you do that experiment, let me review the Sniper documentation again and see if I can determine all the options we have to work with.

Installed it and took a brief look, seems to be working and I like the software, but we'll want more data to really get a feel for things.  My first piece of advice is that when you take a datalog, you want to get good long stretches of 'common' driving conditions.  So get a few good long idle sessions (this log has one or two, so that's OK), then you want some cruising at different but constant RPMs.  So cruise for a while at 2500, 3500, and 5000 RPM for say 30 full seconds each.  Then you want some full throttle measurements, so run through the low gears a few times with full throttle up to redline. Lastly, again run up through the rev range but at part throttle, like you'd accelerate in traffic but keep the throttle constant and let it rev all the way up.

Biggest thing I see from this log is that the acceleration enrichment needs some work; you're getting big lean spikes whenever you're rolling on or off the throttle.  Does the sniper autotune accel enrichment too and/or are there manual settings to play with?

Oh, and probably the best/simplest way that I like to view a datalog is as follows:

Start with RPM, MAP, and AFR graphs.  This lets you see the engine's 'response' (AFR) at a given speed (RPM) and load (MAP).  This gives the best overview, then you can add/subtract stuff to look at specifics in small areas.

Lastly, I'm definitely going to recommend changing your ignition timing a bit; 2.7 degrees at idle is kinda ridiculously low; you should be somewhere in the teens.  36-37 degrees all in looks pretty good though.  And generally you can run *more* advance at low throttle and *less* at higher load, and I think you have that a bit the other way around.  Hope this helps!

Fantastic news! Congrats on the major success!!! Can't wait to hear how is running here shortly as you get things dialed in!

Feels good to get all of that crap cleared out of there, doesn't it? And don't worry too much about your first attempt issue, I generally ended up doing each section of my Megasquirt wiring about 3 times on average before I was happy with things!  Just how wiring goes, bit of an iterative process!

Great stuff! Glad the linkage looks easy; hope it remains that way! And don't be scared to test into the smog wiring with abandon; you 110% won't ever want it back, and it's easy to avoid the important stuff. In a non-tii, there are only 3 important wires that run across the firewall: green wire for the coil, black wire for the tach, and whatever color wire that runs to the oil pressure sensor. Isolate those and kill everything else!

I'm assuming the Holley unit has its own fuel pressure regulator on there somewhere, but is it vacuum compensated?  Most FPRs (that I'm used to) have a vacuum line going to them so the the pressure drop remains CONSTANT between the fuel pressure in the rail/top side of the injectors and the intake manifold, regardless of the manifold pressure.  I say all this just to warn you to not be surprised if you see changes in the absolute fuel pressure when you open/close the throttle, as that's just the FPR reacting/adjusting to the changes in the manifold pressure.

I suppose it would also be possible to leave the fuel pressure constant in absolute terms, and then just adjust the injector fueling times further to compensate for the MAP deltas, but I don't know of a setup that works this way, so it'd be interesting to know if that's how the Sniper works instead!