Up to you really.

The MS2 with ms2/extra should work fine as long as the supporting board is in good order.

It does have some goodies that aren't in the ms1, but the main thing most people notice is just how much smoother the engine runs on it.

You could always just pick up the ms1 chip as a spare since it's so cheap.

Ken

 

im having a good feeling here buddy. i really hope this fixes some things. i have been fighting this ms for months.

 

sorry this is slightly diverging from the specific issue, but i just want to check my method for determining that low rpm, and figure out if the issue is simply that the engine is not cranking as fast as it should for some other reason:

i know this method is a little back asswards, but it seemed like the simplest way at 2:00am the other night, think it should be valid:
i count 6 pulses in 2.2 seconds
every exhaust pulse is equal to 0.65 liters of displacement.
6 exhasut pulses equals 0.65*6 = 3.9 liters of exhausted air. the 13b, unlike a piston engine intakes (and thus exhausts) its rated displacement (1.3L) every rotation of the E-shaft,
(3.9 liters) / (1.3 liters/rotation) = (3 rotations)
so it took 2.2 seconds to go through 3 rotations.
(3 rot/2.2 sec) = (1.3636 rot/sec)
(1.3636 rot/sec) * (60 sec/ 1 min) = 81.8181 rot/min
did i mess something up on one of the early steps?
if i am in fact cranking at 80 rpm when most are well above 100, i guess that's my issue.

i have deleted my OMP and am running pre-mix, however for testing purposes we have our fuel pump shut off. I put a few drops of 3in1 oil through the trailing holes in each rotor chamber (by turning the motor over by hand to get to each rotor chamber). when we do turn over with the starter motor, small puffs of smoke come from the headers, i assumed that this was some of the nasty carbon, oil and fuel in the rotor chambers buring off (its really black in there). should i hook the fuel pump back on, could this be an issue of inadiquate lube?

I will try to re-test the actual rpm the engine is cranking by the method you mentioned by monitoring the CAS tomorrow.
Thanks, Max

 

dude, i gotta be honest. reading that hurt my head. the best way i know of is to look at the top of the cas and count how many times it goes around for a given period and figure it out. without doing the math i think it still goes for 2rpms ever time the cas goes around once. on my car, the cas goes around about 1.5 times a second. that means that, 1 revolution of the cas is 720* of the crank. 1.5 times that is 1080. 1080/360=3. 3 times a second x 60 seconds = 180rpms. fastest method for the lazy. i know cuz thats how i do it.

 

Using your 2.2 seconds for 6 pulses, I came up with about 81.9 rpms using a slightly different method from what you used.

I've never had reliable starting at anything less than about 180 rpms. Most of the engines I've tuned with healthy batteries and starters crank closer to 280.

Ken

 

well we finally (sort of) solved the problem. However, we changes more than one variable here, so I'm not positive which did the trick.

we changed the pots on MS. looking at it from the back, the right pot is turned all the way to the right, and the left pot is all the way to the left.
the other main thing was that the resistance in the amp circuit was the wrong value. my EE buddies soldiered in a couple more resister (in parallel i believe) to increase the gain of the amp. (sorry i don't know jack about electronics)

we left the air gap in the CAS where it was (its VERY close already)
we also attached the CAS to the relay board with some CAT5 twisted pair wire, though I don't think we had interference problems.

we cranked the engine over with the starter motor, but without the spark plugs connected. instead we attached the relay board to an external ignition circuit that we could visually observe to check for sparking. when we crank the motor over we still get just barely above 80 rpm, but with the changes we made, this registers in MegaTune, and the testing spark plugs fire!!

I looked at the CAS wheel and while we cranked i clapped my hands every time a missing tooth (TDC) passed by the VR pick-up. my hand claps were perfectly synced to the spark firing, so it looks like all the MS configurations are correct.

We also tore down and cleaned the starter motor. this seemed to help a very small amount, as we got maybe an additional 10 rpm out of cranking the engine.

The engine spins quite freely by hand, so i must have a bum starter. i'm going to get it tested at Murray's. anybody know what the current draw is supposed to be? anybody recommend a place to buy a starter motor? should i go used, or spend the money for a new one?

 

The pots, if installed correctly, should both be fully counter-clockwise...

Also, I suppose it's not surprising that you had to modify the VR circuit to pick up a signal at such low rpm. My bench-testing setup barely picked up at that rpm. In the car there are plenty of other things that could make it not pick up at all.

Ken

 

ken, im having a retard moment here. i built up the new ms2 stuff, retested the serial curcuit with the new configuration. i did the hyperterminal test and it works. then i tried to download firmware and there was no port connection... so then i redid the hyperterminal test. fine again. then tried to test communication in settings with megatune. no response. any idea what im doing wrong? i also looked at the ms2 bootload jumper and didnt know what to do with it. i guess when the blue thing is on the pins, it is jumped, and with out the blue thing it is not jumped?

so just to be clear, the hyperterminal is communicating with cpu pins 12 and 13 jumped. but to download firmware or communications test, i have no repsonse from port. both are set to the same com4 port, with matchinig baud rates at
115xxxbps?

also im using the megasquirt downloader tool to download firmware as per the manual.

 

For ms2/extra 1.0, the megasquirt download tool should work fine, you just have to jumper the pins, (blue thing on both pins) and run that tool with the correct com port, and it should just work.

115200 8 N 1 should be the settings.

For megatune, you'll have to follow the instructions for setting up for ms2, but replace the megasquirt-II.ini file with the megasquirt-ii.ini.ms2extra file that's in the firmware release.

With the 2.x firmwares, you have to use the included batch file to upload firmware.

Ken

 

i downloaded megatune with release 1.0.4 as a package, so the .ini file should already be correct. my communications settings are correct, my hyperterminal is funtioning, and i'm jumping the boot loader with the blue things. megatune comm settings match the megasquirt downloader comm settings, but it won't download.

 

This is going to be difficult to diagnose then... Can you post pics of the physical MS2, how it's inserted into the main board, the jumper, and screenshots of the ms2 downloader config?

Thanks,

Ken

 

hey ken. um no need for all that. i finally got it to download. dont know what i did different but it worked. it said 2999 downloaded and 8 skipped what ever that means.

the bad new is after setting my settings to the guide i been using, i still dont have a tach signal. so i guess i got a problem with the components. with what ive done so far, do you think i should still replace the op amp and q22, 23 transistors? and if so, can i use a generic op amp from say... radioshack?

i was reading auricoms post and i see how they amplified the signal, not sure if that would help. i know how on the old board that i could get signal above 400, i guess because its stronger signal there. but this is a different board. i havent tried ms2 on the cas yet. i really dont know how i have the same problem on both boards though. all different parts on each. the guy i bought the first board from assembled the components, and i did the new one. how likely is it we both burn the op amp. and if i recall correctly, when i first got the old board, the rpms worked until i started to tinker with it. thats why i thought i may have burnt up the cpu. but now i have a new op amp, new board, new cpu, and new transistors. after i got the new firmware downloaded, and setup my config. i tested voltage at tachselect-vrin and it moves between .1-2.xxV with the pots adjusting on stim.

 

having a brain fart...please assist:

i'm setting up the final parameters in MS to run spark...
There should be 4 sparks for every one full revolutions of the CAS right? one every 90 deg right?

Also, anyone tried to get the timing precise using a timing light or something? I mean, just so you aren't accidentally like 15 deg more advance than you thought when you first start up?

 

use a timing light for a 2 stroke for the correct timing. or a 4 stroke and divide by 2 i think. or is it multiply by 2? and set your fixed timing to 10 or 5? i cant remember. in your settings for spark. do a search in this forum. its all over the place.

 

i was just looking at the schematic on the megamanual site, and the way i see it is im getting 3.6v to pin 14 of the cpu, which would be irq, the tach signal and it comes from the tsel jumper. the tsel jumper gets signal from pin 7 on the u7 chip. it also is reading 3.6v. but from the schematic, i cant tell what the voltage is supposed to be reading. i guess its is ac voltage, and i have a digital multimeter. i see where the signal goes into u7 from the schematic but also dont know what it should be reading. im gonna post a question on that forum and see if someone can lead me in the right direction to figure out where my tach signal disapears or where its getting scrambled. and im in touch with diy about the op amp and transistors just incase. <big sigh> this is depressing.

 

For timing, just set fixed timing to -5, and adjust the timing using the CAS.

A plain old timing light without a dial works fine for me.

 

The op-amp probably wasn't broken in both cases, the board you were getting 400 rpms on was probably fine, and you probably had some other problem causing it not to work.

The new board probably has one or more damaged components... and the only ones that are easily damaged are the op-amp, and the two transistors.

Call up DIY autotune, and I'm sure they'll help you get the new components, and possibly even the socket for the op-amp.

I doubt that the problem is the ms2 or settings, and none of the other components are really easily damaged.

Ken

 

well i tried msefi.com forums and i only got one response after several days, and that guy pretty much told me to check the manual before i post. that erks me out. i been checking everything on the internet with the word megasquirt in it for months. so no leads there. still waiting on my op amp and transistors to arrive.

 

we got our guy idling this weekend. we are getting backfires when it shuts down, but it seems to work well when it is actually idling.

ken, we found a post you made about how to setup the CAS, and it seemed to do the trick, thanks a lot for all the good info you post about this stuff.

It takes quite a few tries to get it to start when it hasn't run in a while. after it has been running for a while, it usually starts right up again. that thermal unit in the oil pan is in fact an oil heater, correct? could the difficult starter be a vicosity issue due to low oil temps, or is it more likely a wall wetting issue due to cold runners? we only have our primary fuel injectors connected now. we don't rev it very high, but we've pushed it up to around 3000 rpm, and MS reads an injector duty cycle of around 14% (i programmed in 550 cc inectors, but i need to confirm that thoes are what we have) i'm probably going to order a wideband and just stick it up one of the primaries, and try and get an accurate AFR next weekend. i think the AFR is alright for the most part, lots of smoke comes out of the pipes while we are cranking, but it seems to dissappear for the most part when we are actually running. the other task for next weekend is to swap the secondary aux port actuators and VDI actuators with electric actuators and use the MS proto area to control them. anyone tried this?

 

ken i dont understand this situation. as per the ms manual and trouble shooting, i have tested everything on the board for where there should be rpm signal, all the way from the stim to the ms2 card pin 14. it all checks out with about 3.6dcv at pin 14 or 7.1acv. this is what the manual told me to test. the signal is there. how can i not see it on megatune, and why wont the ms2 accept it and "start up". the stim is still giving the no rpm signal with the leds.

 

Most likely you just need to tune your cranking pulse-widths, and cranking rpm.

Probably neither... you probably just need to mess with your settings to get it right. Wall-wetting doesn't occur TOO bad on the primaries since they're squirting pretty much directly into the ports.

I did this on the first rx7 to run the stock ignition system on the MS (tofuball's S5 'vert).

It wasn't difficult, just build a couple of transistor circuits, and use them to trigger relays, or use higher-current transistors to directly trigger the solenoids.

Unless you're talking about stepper motors or something.

Ken

 

If this were happening to me, I'd get out the schematic for that circuit, and hook my o-scope up to various places in that circuit.

I'd look for a proper AC signal coming into the conditioner circuit, and I'd check for the proper square-wave coming out (going into the CPU). If either of those were bad, I'd know where to start debugging.

What I think is probably happening to you is that you're getting input into the circuit, but the circuit is not generating the square wave that's supposed to go into the CPU.

There is no "ms2 is not accepting the signal," only "the circuit that outputs the signal to the CPU is not outputting it."

The only likely reason that the processor would not see a signal there if the conditioner is properly outputting it is if the processor was broken. I doubt that this is the case.

Ken

 

so the only true way to know where the signal is and is not is with a oscilloscope to see if a real signal is actually there rather than just a voltage, right. this would detect the ups and downs in the signal as well as the frequency. the frequency gives is the cycle or rpms. i dont even know how to get a o-scope. but if the op amp is the conditioner circuit point at which it could fail... thats in the mail on the way here. cuz i know i have a voltage coming out of the opamp, but dont know what kind i guess. i like your answer. that alone has made the most sense to me from everything i ive heard. i will have to locate an o-scope cheaply i guess. thanks

 

You can find cheap oscilloscopes on ebay pretty easily.

That's where I've bought both of my scopes.

Ken

 

You may just want to send that unit out for repair. Peter on msefi has a good reputation in that regard.

http://www.msefi.com/viewtopic.php?t=4589