Desperate for some Help With Microsquirt, Beyond Frustrated Options

[JamesM]

Please do not misunderstand my question, I am an inquisitive person and only seek accurate information, not to start a heated debate. The question is purely rational and not subjective. When a bold claim like that is made it requires justification otherwise the myth that D-Jet is somehow problematic/flawed/inefficient/etc. continues without justification.

I totally understand as I am very data driven person myself. Much like the carbs vs d-jet discussions the Megasquirt vs anything discussions have a tendency to devolve hence my response and my reluctance to even post on the subject anymore.

That being said, and not having been the one to have made the statement here I can only comment on what I know about. I do know that the particular motor in question was not stock so I am going to assume the rest of the statement should have been "performs better than the stock system on my motor."

To be clear, I love a well running d-jet system on a bone stock motor. I have both a d-jet 1.7 and a d-jet 2.0 that amaze me every time i turn the key, they start on the first compression stroke and I am in awe that these 45 year old parts still perform so well.

My appreciation of Megasquirt has to do with it being a technical advancement that allows optimization and precision not possible with d-jet. Added bonus is that is is also tune-able to any modification you make to the motor.

From my perspective, any quality made, appropriate to the engine, properly adjusted FI system is as good as another in terms of how the engine performs and functions.

I do not believe this is an accurate assumption. If it were why are all Porsches today not running D-jet? Technological improvements have been made that result in real world benefits. At the most basic level, putting aside the massive feature set of Megasquirt and the documented shortcomings of D-jet wiring connectors and just comparing the two systems from a fueling standpoint there are still advantages to Megasquirt. Specifically I am referring to the accuracy of supplying fuel based on an analog curve vs a digital programmable fuel map. Yes under some conditions (specifically the points in the curve the d-jet system has been tuned to) the fueling of the two systems will be identical however outside of those very specific points the curve approximating fuel needs is just that, an approximation. It may be close, but a digital map will be closer if not dead on. In addition, the needs of an engine are not always on a perfect curve. The engine in my autocross car for example once the fuel map was completely dialed in for whatever reason has a noticeable dip in fuel needs at WOT around 3200-3600 rpm so looking at it on paper the fuel curve at WOT is not a curve but looks more like a 2 humped camel. A d-jet setup on this motor could be tuned to produce a perfect mixture at couple specific points but because of the shape of the fuel requirements it would always hit a rich spot around 3200 RPM at WOT unless it was tuned to be dead on at 3200 RPM in which case it would be lean everywhere else. Would it be noticed from the drivers seat? Who knows, but it can be seen in the data.

Add to that O2 closed loop operation and you just increase the real world accuracy of the system even more.

And that is just fueling. Megasquirt has a complete engine management feature set and the advantages that the accuracy of a digital system provides are multiplied as soon as you add ignition control which is really where i feel the most gains are. You can visibly see the difference with a timing light between a car running a stock distributor and one running a 36-1 tooth wheel with wasted spark. You can also again tune the ignition table in ways that are just not possible with analog advance weights and vacuum canisters.

I can go more in-depth but the bottom line is always accuracy improves performance and efficiency and Megasquirt can be tuned to a higher level of accuracy across all running conditions than d-jet, even on a stock motor. Nothing "wrong" with d-jet, its just the nature of the two systems. Points that can be made to the advantages of d-jet over carbs are similar to the ones that can be made about Megasquirt over d-jet. Its further refinement and less compromises.

[JeffBowlsby]

Thanks for the detailed follow-up James. We basically agree on everything important. MS and others can be excellent FI solutions for those willing to pay the price.

100% disagree with the comment on the D-Jet terminals. Lets forget this myth it has no substance. Greenwood promotes a beyond-extremist perspective if that is your source, he has provided nothing to back up his claims. Perhaps on paper, in a lab setting under forensic evaluation they are not the most optimal engineering solution and 100% agree that L-Jet style hardware is a significant technical improvement towards connectivity, but that does not make the D-Jet terminals fatally flawed. No 914s or other D-Jet cars have burned to the ground because of this terminal. How many D-Jet cars still have their original harnesses using those 45 year old terminals? Every 914 I have ever owned has its original harness and several of those cars I drove daily for many years with never a related fault. VWs, MBs, Volvo's - a significant number of cars used D-Jet around the world and continue to use it and its hardware to this day without issue.

AS you mention, our D-Jets on stock engines are perfectly suitable solutions for what they are, I would argue that they were not designed to provide the level of precision that newer digital based FI systems are capable of, nor do our stock engines demand that level of precision. So the higher precisoin is more of a novelty only, where it is not essential to the needs of the engine. Because they can be so sophisticated to set-up, custom fit and calibrate, it is disheartening to see some that attempt the conversion not be successful or not successful without extreme dedication and sacrifice - the effort and cost needed can be a significant price to pay. The conversions can be and are done, but at what cost in time and materials? The most expensive part of the D-Jet is the MPS and rebuilts are available for $300. and its a bolt in solution. If folks want to go to the trouble of an FI conversion, or need to because of engine mods, they just need to be aware of the full impacts of that decision - either way they have my full support as long as they are fully informed.

[StratPlayer]

Great read guys, for I am one with a Djet and original harness.

[Mblizzard]

Well all is running with just a few minor issues. Most of them self inflicted wounds!

Still working with the idle adjustments and I am seeing some higher CHT temps than I want. Playing with the timing a bit to see if I can get them down. May just wind up adding some more fuel in to cool things off more at cruising speeds.

The one thing I was wondering is because I am not controlling timing yet should I be using the tooth wheel setting? It pulls some adjustment for timing based on rpm from a table which I have set up to mimic the factory timing.

Not sure it makes much difference but I have been struggling with the timing for the CHT temps and not met with much success. Running at above 350 most of the time and it heats up rapidly on hill climbs. In fact I reduces it to about 23 degrees and the temps were worse. So I was wondering if the timing of the fuel injection could be part of this?

Hoping for the best on the trip and because I have the ECU set up with Bluetooth connection and I am running MSDROID on a tablet I should be able to make fuel corrections as need on the trip to Okteenerfest.

[jpnovak]

Your post is contradictory. In one line you are changing timing to help CHT. In the next section you are fuel-only and not controlling timing.

If you are running timing through the distributor then changes to the timing curve will not make any difference to your tune. They are just parameters that go nowhere and have no function.

If you want to run with a more lean AFR (lean burn) you generally have to advance the timing to match. This is usually done on low throttle cruise bins. However, if you are not controlling timing then you are at the mercy of the timing generated by your dizzy curve.

Glad that the car is running well. Continue to tune. During the trip you can change the target AFR, adjust the fuel trim and find the balance of power, fuel mileage and CHT.

[Mblizzard]

Your post is contradictory. In one line you are changing timing to help CHT. In the next section you are fuel-only and not controlling timing.

If you are running timing through the distributor then changes to the timing curve will not make any difference to your tune. They are just parameters that go nowhere and have no function.

If you want to run with a more lean AFR (lean burn) you generally have to advance the timing to match. This is usually done on low throttle cruise bins. However, if you are not controlling timing then you are at the mercy of the timing generated by your dizzy curve.

Glad that the car is running well. Continue to tune. During the trip you can change the target AFR, adjust the fuel trim and find the balance of power, fuel mileage and CHT.

I am not controlling time with the Microsquirt. I definitely could be wrong but I understood that the when using the tooth wheel set up you can select use table for timing. I don't know if this table impacts the firing of the injectors. I think it would not be related as you suggest but just wanted to confirm I was not missing something.

[jd74914]

I am not controlling time with the Microsquirt. I definitely could be wrong but I understood that the when using the tooth wheel set up you can select use table for timing. I don't know if this table impacts the firing of the injectors. I think it would not be related as you suggest but just wanted to confirm I was not missing something.

There should be a fuel injection timing table which controls either the start or end of the injection cycle. What is yours set at?

In my experience, injection timing doesn't really have a huge effect on overall engine performance unless it is wayyyyy off and all you're doing is pooling in the manifold. It can subtly change throttle response, making transients a bit better, and also has a slight effect on torque, but I've only seen that on an engine dyno after many hours of tuning. Your AFR can also be a little weird if its way off and you're sending gas right out the exhaust port as IV/EV timing overlaps. Again, this is pretty subtle, nothing like the changes even a few degrees of ignition timing might make.

[Mblizzard]

I am not controlling time with the Microsquirt. I definitely could be wrong but I understood that the when using the tooth wheel set up you can select use table for timing. I don't know if this table impacts the firing of the injectors. I think it would not be related as you suggest but just wanted to confirm I was not missing something.

There should be a fuel injection timing table which controls either the start or end of the injection cycle. What is yours set at?

In my experience, injection timing doesn't really have a huge effect on overall engine performance unless it is wayyyyy off and all you're doing is pooling in the manifold. It can subtly change throttle response, making transients a bit better, and also has a slight effect on torque, but I've only seen that on an engine dyno after many hours of tuning. Your AFR can also be a little weird if its way off and you're sending gas right out the exhaust port as IV/EV timing overlaps. Again, this is pretty subtle, nothing like the changes even a few degrees of ignition timing might make.

This is what I have for my timing settings.



This is base don information from McMark.



So I am assuming the ECU knows when TDC occurs and fires the injector based on that.

Is there another setting for the injector timing?

[McMark]

Injector timing is fixed. There is a setting for it, but I'm not advanced enough to know how big of an impact it can have. My intuition says that it's not very relevant at low levels of tuning. Much like sequential injection doesn't seem to have a large impact on rough tuned engines.

Mike, is your distributors mechanical advanced locked out? You have two options with the distributor/ignition.
1. Lock the MicroSquirt ignition (top left of your image, change the Fixed Advance setting from Use Table to Fixed Timing).
2. Lock the distributor (glue the weights, or otherwise stop the mechanical advance) and use the MicroSquirt timing table to control advance.

If you're distributor isn't locked and your setting are like the image you posted, you have two systems fiddling with timing. The results will be unpredictable.

[Mblizzard]

Injector timing is fixed. There is a setting for it, but I'm not advanced enough to know how big of an impact it can have. My intuition says that it's not very relevant at low levels of tuning. Much like sequential injection doesn't seem to have a large impact on rough tuned engines.

Mike, is your distributors mechanical advanced locked out? You have two options with the distributor/ignition.
1. Lock the MicroSquirt ignition (top left of your image, change the Fixed Advance setting from Use Table to Fixed Timing).
2. Lock the distributor (glue the weights, or otherwise stop the mechanical advance) and use the MicroSquirt timing table to control advance.

If you're distributor isn't locked and your setting are like the image you posted, you have two systems fiddling with timing. The results will be unpredictable.

Not sure I see the potential for the systems to compete. The ECU has no control over actual timing. It is only firing the injectors based on the signal coming from the tooth wheel.

[McMark]

Ahhh, that's right. Now I remember how your ignition is set up. Yeah, there's no overlap.

Look under Basic Settings -> Engine and Sequential Settings.

Sequential Injection setting is probably set to Untimed. You can set it to Semi-sequential to specify the crank angle. I would search for a good reason to do it before switching. I doubt it's going to magically solve any problems.

[jpnovak]

OK. Clear now. Your original post about timing was referring to injector timing relative to crank angle. This will have almost no effect on CHT unless you are overheating at idle or very low rpm. ONce you above about 1500rpm the injectors are spraying fast enough (and in batch mode) that you will see almost no difference.

If you were running sequential or some variant then you would see a greater effect where the fuel can puddle on the topside of the intake valve if the timing was VERY wrong.

high CHT could be running lean or wrong IGNITION timing. Have you verified your ignition advance curve with a timing light? Is the timing too advanced?

[Mblizzard]

Well I got a few hundred miles on the car at Okteenerfest. With a few minor adjustments here and there I was able to keep my head temps in reasonable ranges and enjoyed a pretty good power range. Admidittly it took a few atttemps to get dialed in but using MSdroid on my tablet made the MicroSquirt changes so easy but using a old school timing light to make slight changes in timing was more difficult.

Extremely happy with the performance and the ease of adjustment. Ran pretty much flawlessly the whole weekend and performed well enough in all areas of the power band to all me to keep up with some pretty good cars. Not any faster but certainly more consistent performance across a much wider area.

I think once I switch the timing control it will be even better.

Again thanks to everyone for you help. you will likely see a similar thread when i start converting the timing. (IMG:style_emoticons/default/evilgrin.gif)

[Mark Henry]

Well all is running with just a few minor issues. Most of them self inflicted wounds!

Still working with the idle adjustments and I am seeing some higher CHT temps than I want. Playing with the timing a bit to see if I can get them down. May just wind up adding some more fuel in to cool things off more at cruising speeds.

The one thing I was wondering is because I am not controlling timing yet should I be using the tooth wheel setting? It pulls some adjustment for timing based on rpm from a table which I have set up to mimic the factory timing.

Not sure it makes much difference but I have been struggling with the timing for the CHT temps and not met with much success. Running at above 350 most of the time and it heats up rapidly on hill climbs. In fact I reduces it to about 23 degrees and the temps were worse. So I was wondering if the timing of the fuel injection could be part of this?

Hoping for the best on the trip and because I have the ECU set up with Bluetooth connection and I am running MSDROID on a tablet I should be able to make fuel corrections as need on the trip to Okteenerfest.

My experience would say you're trying to achieve too lean of AFR especially on WOT or load. I can do 14:1 with my car because it has nickies, but every iron cylinder car I've tested/tuned 13.5:1 is the big load (hill) max, trying to lean it out further has always resulted in skyrocketing head temps. this often is combined with little or no recovery on the downside of the hill.
Frankly once you get beyond a certain head temp heat soak sets in and it will never recover.

You have to totally ignore the results for water cooled cars, they have way more control over head temps and can do the lean burn trick. You have to remember that the aircooled engine is based on a 1930's design. Some say aircooled, some say air/oil cooled, really it's air/oil and fuel charge cooled.
You have to run a bit rich, you have to run at minimum 3K RPM because leaning out and lugging an aircooled will kill the engine PDQ.

I get into arguments about aircooled AFR all the time, least I used too, guys basically saying I'm an idiot and "what does he know".
Then in short order I'll hear thru the grapevine the same person who wouldn't listen to me has dropped a valve seat, etc.

[Mblizzard]

Well all is running with just a few minor issues. Most of them self inflicted wounds!

Still working with the idle adjustments and I am seeing some higher CHT temps than I want. Playing with the timing a bit to see if I can get them down. May just wind up adding some more fuel in to cool things off more at cruising speeds.

The one thing I was wondering is because I am not controlling timing yet should I be using the tooth wheel setting? It pulls some adjustment for timing based on rpm from a table which I have set up to mimic the factory timing.

Not sure it makes much difference but I have been struggling with the timing for the CHT temps and not met with much success. Running at above 350 most of the time and it heats up rapidly on hill climbs. In fact I reduces it to about 23 degrees and the temps were worse. So I was wondering if the timing of the fuel injection could be part of this?

Hoping for the best on the trip and because I have the ECU set up with Bluetooth connection and I am running MSDROID on a tablet I should be able to make fuel corrections as need on the trip to Okteenerfest.

My experience would say you're trying to achieve too lean of AFR especially on WOT or load. I can do 14:1 with my car because it has nickies, but every iron cylinder car I've tested/tuned 13.5:1 is the big load (hill) max, trying to lean it out further has always resulted in skyrocketing head temps. this often is combined with little or no recovery on the downside of the hill.
Frankly once you get beyond a certain head temp heat soak sets in and it will never recover.

You have to totally ignore the results for water cooled cars, they have way more control over head temps and can do the lean burn trick. You have to remember that the aircooled engine is based on a 1930's design. Some say aircooled, some say air/oil cooled, really it's air/oil and fuel charge cooled.
You have to run a bit rich, you have to run at minimum 3K RPM because leaning out and lugging an aircooled will kill the engine PDQ.

I get into arguments about aircooled AFR all the time, least I used too, guys basically saying I'm an idiot and "what does he know".
Then in short order I'll hear thru the grapevine the same person who wouldn't listen to me has dropped a valve seat, etc.

Well to add to your wise insight I had a discussion with a man I respect imesenly. Lewis Broyles and he pointed out that it did not matter what your past experience told you or what any gauge said. The air cooled engine needs more fuel to run cool. I added that fuel and have been enjoying the benefits the whole Okteenerfest weekend. Still have a few rough points to refine but what a blast the car was to drive this weekend.

Ran with a few big dogs. Admittedly a few steps behind but still in the mix. Certainly a driver with more skill than i have could have done more. But damn that was fun! Never had such predictable performance with the D-jet. Could be just due to my lack of understanding with the D-jet but stil it was beyond epic!

[Eric_Shea]

We're lucky to have James in our back yard.

We have one amazing stock d-jet system in Jim's car but, I'm biting my nails every time he turns the key. These systems are old and having a perfect, running system these days is like finding a needle in a haystack. So is find parts for them.

We also have one amazing custom 2270 MicroSquirt system in Scott's car. It is absolutely "jaw dropping" (there's a technical phrase you can write a white paper on) in how it performs. Imagine how a brand new Type 4 motor would perform today with modern FI from a 2017 Macan as an "example" (but totally open sourced). To watch James sit in the passengers seat and fine tune this motor while you're doing 3rd gear pulls from 1,000 rpm will bring a tear to any 914 owners eye.

Cam? Any cam you want.
AFR? Any AFR you want at any RPM or altitude.
Advance? You guessed it.

Congrats Mike! Sounds like you're well on your way to having a killer motor.

[McMark]

Just went through configuring a MicroSquirt brain running MS2E firmware and the trigger offset (Trigger #1 Angle) settings are calculated differently between the two firmwares.

MicroSquirt 3.83 firmware would end up being around 290° as mentioned above.

but...
Mike is running the MS2E firmware and the angle for that is around 60°.

[Mblizzard]

Was just looking through a couple of options for coils and saw this using a VW coil.



Seems to be too simple? Would fire in essentially 2 banks?

Any thoughts? The coil is only $18!

[Mblizzard]

Been looking through the information and i still have no idea how firing order and such is set?

Will be using the EFI Quadspark and Tower 4 coil. But just have not grasped the setup and how to specify firing order.

Once I get the hardware in I will start an ignition thread.

[McMark]

Seems to be too simple?

Ignition is simple.

The coil you pictured (and most like it) have two ignitors built in, which controlled by the blue wires in the above picture. The ECU triggers each wire separately, every 180degrees. The spark plug outlet/wire connections are paired. So the coil pictured above the top two connections fire simultaneously (pair A), and the bottom two fire simultaneously (pair B). This means that each cylinder fires twice per cycle, this is not like the stock setup.

The ECU is hardcoded to trigger IGNOUT 1 as cylinder #1.
So cylinders #1 and #3 get connected to the coil controlled by IGNOUT 1, and cylinders #2 and #4 connect to the coil controlled by IGNOUT 2.

The firing order is set by your spark plug connections.

This is Wasted Spark. If it's still confusing, research Wasted Spark because I bet that will clarify things.

But there's not software setting for firing order. You just have to hook it up right, which really is just like a standard distributor. You can screw up your firing order on a stock engine just by swapping two wires. Same thing with the coil you pictured. You can screw it up (or make it right) just by moving the spark plug wires. NOTE: Some coils come with cylinder numbers embossed/scribed into the body of the coil, THIS MAY NOT BE CORRECT FOR YOUR ENGINE. Those numbers are to guide/help people installing that coil into the car it was designed for. You're not doing that, so those numbers (if they exist) aren't for you. Sand them off or just ignore them.

tl;dr -- Firing order is set simply by hooking the spark plug wires to the correct spots, and that's all.