mcm375

Interesting timing for this question, I broke down today and bought a "real" timing light with advance/dwell control etc etc so I could pinpoint how accurate the ignition driving through VAST really is vs the commanded timing by MS...

Here is what I observed:

This configuration in MS is "correct" for the VAST system:



However I see a 5 degree variance between my timing @ idle vs my timing at 3000-5000 rpm. I have dialed in my distributor to provide correct actual spark firing timing vs MS commanded timing at the high RPM range since this is the most critical area to control.

I do not know why there is this 5 degree variance over the rev range, but I have ruled out it being a case of incorrect Ignition Capture / Spark Output parameters because if those were wrong my timing over the rev range would be additive to dwell duration for any particular engine speed and since dwell duration is fixed, dwell angle directly correlates to engine speed, and my dwell angle as measured by my clever new timing light is 12 degrees at idle and over 30 degrees at 4000ish RPM. Plus I tested all 4 combinations of settings and the other 3 do demonstrate timing that varies with dwell angle...

PHEW.. that was a mouthful, hope it made sense.

My assumption at this stage is that what I am seeing is an inherent limitation in the 4 "tooth" distributor pickup via VAST that is being fed into the MS via an Opto input with 12v pullup.

Anyway, I figure I can "account for" a 5 degree more-advanced-than-commanded timing at/around idle speeds in my ignition timing table.

Now speaking of ignition timing, here is my current map:



However note that I have not yet gone back to lower the low RPM figures (below 1000rpm) to account for the 5 degree variance discovered above. It idles fine at -13degrees advance anyway, so maybe this isn't worth concerning myself.

The "range" in this map that I am concerned about is 2500rpm - 6000rpm and between 59 and 98 ignload values. I brought these down considerably to avoid audible pinging (which sounds like a very light "tink" on this motor?) and note that I AM running 91 octane here in California (which is E10). So it seems that this motor does NOT like a lot of advance...

mcm375

I am fairly sure there is a good deal going right now for LC-1's from Innovate for right on $200 or less. You don't need the gauge-included version unless you like eye candy in the cab.

My total cost was $600 from diyautotune.com, but I also grabbed some components you might not want or need.

I will say I then went and bought about $30 worth of electronic components, for example hoods and solder cup DB15 pin connections, acouple hundred feed of 18 gauge high temp wire, and a cable cover. This was for my little central pod thing I made to hold a bunch of gauge and be a central connection point for stuff in my truck. I ran the DB15 from the MS to this for aux inputs/outputs. Pretty sweet.

I would realistically give yourself a $1k budget for this because there WILL be tons of you will suddenly be able to do and want to do, for example if you have a turbo truck you will want to setup a PWM solinoid for boost control. You may want to implement an IAC valve, you may want to go to an electric fan with MS control, you may want to eliminate your intake tract and go to a nice cone filter on the TB, etc etc.. Then there's aux switches and LEDs or indicators, gauges, etc you may want to add because its now very easy to do.

So go with a $1k budget and you will stick to that budget I think.

mcm375

Started with ronmar's conservative maps (here: http://www.diyautotune.com/diypnp/ap...9-22rte-mt.zip) and basically just retarded things a little from 0-4000rpm.

Today I tried to advance timing a little in the power band but encountered audible detonation when going as far as 27 degrees between 3000-4000 rpm.

P.S., what I believe I'm hearing as detonation is a faint "tink" sound; it is definitely something correlated with spark advancement as I can produce it and eliminate it via timing map adjustments.

Targetnut

Your timing discrepency sounds like a settings issue. If you trigger off the wrong "edge", the dwell variation at higher speeds will change timing.

Also it seems your timing should be higher than that.

and what is the ignload? is that manifold pressure? If so, are you turbocharged? if not, your load bins shouldn't need to go so high.

mcm375

I covered rising/falling edge in my post, it is not a dwell variation which would be (and is, if I deliberately misconfigure the crank input/spark output settings) a much greater variance since dwell at idle is 12 degrees and at 3000rpm is 30 degrees.

Yes I do have too many bins on the spark table. Without a functional knock sensor I am going by ear on detecting knock, and it is quite possible what I think is knock is not; though it seems to complete concord with slightly more advance.

mcm375

A little update:

This weekend I bought a $60 electric fan from Kragen, hooked the positive lead up to the battery and the negative lead to one pole on a spare relay I had lying around. The other side of the Normally Open relay was run to a grounding point on the engine.

For the relay trigger connections, I tapped one into the Vs pin from the old AFM connector (remember I have eliminated my AFM so all pins on the connector are avaialble to simplify wiring into the MegaSquirt ECU) and the other into the Vb pin (which carries 12v with Ign On).

In the MegaSquirt, I jumpered the PT6 Programmable Output to pin A4 on the adapter board, which is the Vs circuit on the car.

So now, MS can control the electric fan based on parameters configured within TunerStudio. In this case, I set the fan to come on when the coolant reaches 200 degrees, and set a hysterisis of 15 degrees (so that the coolant must return to 185 before the fan is switched off again).

So, there is an easy way to get a thermostat controlled radiator fan for $60 + some wiring.

Note that in the near future DiyAutoTune.com will be releating a "GPIO" board for the MS which will allow many more general purpose inputs and outputs. Should be pretty useful for stuff like this.

mcm375

Installed the MAPDaddy 4 Bar w/ Baro MAP sensor, this is very useful for me as I climb/descend 4000ft regularly so having realtime baro correction is a nice feature.



Note that the extra sensor just inputs straight into the BARO IN connection, very handy:



Mounting of the nipple on the case is also much more secure this way, properly attached to the alum case itself rather than any tugging and wrenching forces when attaching/removing the vacuum line being applied to the PCB:



Setup in TunerStudio is very simple, one simply goes to General Settings and specifies "Two Independent Sensors" for the barometric correction parameter, using the SPAREADC port for the Realtime Baro port parameter.



Once you have done this, you can configure your barometric correction curve to tune elevation fueling changes based on your exhaust system's backpressure characteristics. I would recommend going with a linear curve to begin with, here is mine:



Note that 101.3Kpa corresponds with sealevel. The green dot is my current barometric pressure at my house, which is approx 4000ft ASL.

ronmar

Well i was surprised to see my name used IRT this. I actually just registered on this site as i am working on a 4runner project. Anyone has any questions on the DIYPNP project just PM me. It is not fully tuned, but it is/has been daily driven since installation. I have some exhaust/turbo leaks i need to get resolved before I finalize the tune. It is a little on the rich side right now for safety.

As for the ignition table, that table was derived from the factory ECU. I actually zip-tied a timing light and webcam under the hood and went out and collected advance info IRT manifold pressure and RPM.

mcm375

I've made a few changes since last updating this, now have a PWM IAC valve from a crown vic (Borg Warner part) and am using the 3.0.3r alpha firmware. Idle control is now closed loop PID which is really nice, eliminated the coolant-spring aux air contraption (put a plate over it to seal it up) and eliminated the idle set screw. MS controls my idle speed now. Will idle up hills and over obstacles etc as it keeps adjusting the IAC valve to meet a particular target RPM.

I do have a problem with my motor where it burns a lot of oil, seems to be related to the guides or possibly valve seals as oil is sucked into the combustion chambers in great quantities while idling or at very high manifold vacuum. Need to pull head and inspect in the spring, but so far have been daily driving this truck on a DIYPNP Microsquirt setup running 3.0.3r firmware.

mcm375

Ron I have noticed that MS control of the timing via VAST is not perfect, I am seeing a roughly 5 degree variance across the rev range between commanded timing and actual timing.

I am checking this by setting a fixed timing in TunerStudioMS, say 10 degrees, then using my timing light (http://www.equus.com/product_info.ph...tegory_id=1_20, it supports "advance" via strobe delay from 0 to 90 degrees) to dial in the distributor at say idle, but as I open the throttle and engine speeds increase, the timing varies slightly even with the fixed timing configured in MS.

Have you noticed this? My DIYPNP board/pin connections and tune configuration are identical to yours in your guide regarding ignition timing.

ronmar

I havn't noticed any timing discrepancies. I have what I need to recreate my video experiments, and it would be easy enough to compare timing light image with the commanded timing in MS.

In trying to resolve my tune issues(running way lean by O2, but no other indications such as detonation) I looked extensively at the ignition system for potential weak spark. I could find no problems. One thing I was concerned with was possible trigger level issues, with the DIY possibly providing a marginal level to charge and fire the coil. I guess the older MS versions had the ability to set the pullup voltage for this, but the DIY did away with this feature. It is a lower level than the stock ECU provides, but I could find no issue with this level. I had pretty precise dwell control, and if triggering was an issue, the dwell would show it. One thing I discovered in measuring the stock ECU signals into the coil/igniter, was that the stock ECU runs quite a bit of dwell time. Far more than the MS setup instructions reccomend. The dwell also increases with RPM on the factory ECU.

Do you have access to an O-scope? 2 channels, one comparing the spark trigger or input trigger to the injector firing might show input trigger anomolies or MS output trigger issues. But looking at dynamic signals with an O-scope has it's own problems. That was initially how I started to build a timing map from the factory ECU. But the shear number of calculations I would have to do put me off a bit. That was when the light bulb came on. Boy it sure would be easier to do this with a timing light. So I did. I went and bought a $25 webcam and put it and the light under the hood. I made a gauge strip to bolt alongside the pully and put some marks on it up to I think 40BTDC. Here is a link to a short video I saved of this process. You can just see the factory timing marks on the left.


The info I got from the webcam helped me build this timing map for the factory ECU.

Aussie22r

Hi i'm looking to megasquirt my 22re and i have a few questions.

Firstly are you running a/c? if so how was the VSV wired?

Did you need the o2 guage or does the software provide a readout?

Have you thought about running EDIS4 ignition? I'm thinking about running this and was wondering how the wheel mounts to the harmonic balancer?

Thanks and great write up, i'll be stealing your settings to get mine running

ronmar

here is my .02

No I am not running A/C. I am not sure what the factory ECU does with the A/C input from the VSV, but I believe that is all it is, an input to tell the ECU when the compressor is running and VSV is open to provide idle-up. I think you will need to provide this circuit a path to ground as the low pressure switch provides power to the VSV, and without a path to ground, the VSV will not open and increase idle. The low pressure switch also provides power to the the A/C amplifier which engages the A/C compressor. At least in the 86-88 wiring information that I have available. The A/C diagram itself in my factory electrical manual dosn't even show a connection to the ECU, as this manual still covers the carburetted 22R engine, but the ECU diagram shows the input.

The Megatune software can display the O2 output, either narrow band or wideband. It can be configured for pretty much any type O2 sensor you choose. I went with the LC engineering sensor that DIY sells as it seems to be widely used and has a lot of good written about it.

No, I have not. My first step was to get this thing working as plug and play as possible as this truck is needed daily, and tuning can be an involved process. The 3 plugs on the ECU and the one plug on the cold start injector and I am back to the stock configuration in less than a minute. Eventually, I will do away with the AFM and might perhaps go with a direct drive coil using the hall effect pickup in the stock distributor. But for now, the stock VAST ignition system seems to be working well for my needs. And again, dead easy to get started with the DIYPNP...

texcat101

I really like MS setup on my 4.3 swap, no regrets... but IF I would have had a manual trans I would have megasquirted the 22re that I had. I am glad to see someone else has done it. The crappy AFM is the worst enemy of the 22re.

Erik Beeman

Cool thread and all, lots of work into it...but way too complicated. I did MS-II on my 88 in a much way more simple fashion, and for $438 with everything preassembled, with all sensors and vacuum line. Could of gotten it for $170 or so from DIY had I wanted to assemble it myself. I had two jumper wires in the ECU and thats all. Seems pretty similar to your set up. When I MS my 92' in a few weeks I will just build my own wiring harness. Junk the garbage stock ECU's and harness all together. I am running the AEM UEGO wideband, and this is all on a 2WD drift truck. Nice thread tho.

Hayes

could this work with an auto trans?

Erik Beeman

Yes. My 88' is an auto trans

Aussie22r

Thanks for your help ronmar.
Do you know much about the VAST ignition system?, as i have a working 22r dizzy and i believe a working dizzy from a 22re but it has vac advance (Must be really early 22r-e) Can i use this dizzy and just cap the vac sensor? This is the reason i want to run EDIS as 22re parts are as rare as in Australia so sourcing a reasonably priced unit isn't an option as only 1 wrecker in the whole country deals with 22re conversions.

Thanks again

ronmar

The ECT(electronically controlled transmission) version could throw some curves into the mix. I am not exactly sure how the Stock ECU interacts with the ECT...

ronmar

If it has the 4 point wheel and pickup coil/hall effect sensor, then yes. You need the sensor for event timing in MS, but you don't need any vacume advance as the advance info is done by the MS timing map. It has been a while since I messed with a vacume distributor, but I think there is also a mechanical component to the mechanism that incorporates flyweights. You will Want to disable that advance mechanism also.

I have been to Aus a few times. Wonderfull country. Where are you?