Megasquirt users thread to discuss all things Squirty

[thechuckster]

vaguely on topic - Japan's NINS working with Denso to replace spark plugs with lasers:
http://scienceblog.com/44560/laser-s...stion-engines/

... built its laser from two yttrium-aluminum-gallium (YAG) segments, one doped with neodymium, the other with chromium. They bonded the two sections together to form a powerful laser only 9 millimeters in diameter and 11 millimeters long (a bit less than half an inch).

The composite generates two laser beams that can ignite fuel in two separate locations at the same time. This would produce a flame wall that grows faster and more uniformly than one lit by a single laser.

The laser is not strong enough to light the leanest fuel mixtures with a single pulse. By using several 800-picosecond-long pulses, however, they can inject enough energy to ignite the mixture completely.

[old_mr2]

first start help.

I tested my MS2 today in car 4agze and ran into a problem. When i test my distributor with a drill or by hand I get a steady rpm signal in TStudio. But when I put the dizzy in the head and crank the motor, the signal stops.

If i spin by hand or use drill I get rpm signal, spark and fuel? The only time I cant get a RPM signal is when dizzy is in head Has anyone experienced this?

Dizzy works fine with factory ECU.

[oldcorollas]

there should be nothing shorting in the dizzy, such that grounding dizzy to engine is a problem.. esp since it works with stock ECU.

is there any issue with power supplied to the MS during cranking?, ie it has voltage when key is in "on" and "start" positions?

or, is the battery voltage being pulled too low during cranking?

[jabbatron]

..........

[old_mr2]

I forgot to mention something.

I have 2 dizzys giving rpm signal in test conditions. One is complete and the other is missing its cam gear (because we were going to remove a tooth from the 24 point wheel,havent done this yet)

If we wire up the dizzy without the cam gear and put it in the head, you can crank the car and spin its rotor by hand and get rpm, spark and fuel.

But the dizzy with the cam gear on, driven off the camshaft will not give rpm signal.

Summary, whenever dizzy is driven off the camshaft, no rpm signal produced. Otherwise works fine for both dizzys under test conditions.

PS Battery is only 2 months old!

[oldcorollas]

stupid question time...

are you sure the dizzy with cam gear on is actually spinning? ie the gear is not rotating on the shaft and is properly engaged with the cam?

can you spin with drill or by hand at less than cranking speed? ie 1-200rpm?

[old_mr2]

Yes the cam gear is on and has its original pin through it. The dizzy runs the motor fine with factory ECU.

[oldcorollas]

hmm, lots of frustration today, trying to get it to start...
when cranking it pops and splutters but never gets going..
I don't know if it is timing, or if fuel is that diffeent from MS1 setup...

charging battery, will play with trigger offset again next

goddmit... it started, and ran like it was on 1 or 2 cylinders....








it was......
swapped 3 and 4 leads around.. starts easier now... still a long way to go..
no idea why i'm gettign dwell of 12ms...

[RAAAH23]

i guys thought id as the question here rather than open a new thread. i recently started collecting parts for my 2TG overbore/stroker/turbo efi all in one. the main thing here is im on a tight ass budget. i blame 1st yr wages lol. back on track. i picked up a complete efi manifold with ecu resistor block and afm. as im running a turbo (CT20) the stock ecu wont cope with the boost ill need to run another ecu. now remember im on a serious budget and want the ecu to be fuel only what do you guys recommend. ive been told a wolf3d suits my situation great but i do want to upgrade everything slowly and eventually have the ecu running all the show. what megasquirt would fit the bill? how much am i looking at for a used simple unit?


cheers guys

[thechuckster]

Owen's ECU (was for sale) would have suited a 2TG EFI setup just fine. Running MSExtra code it would happily deal with extra stuff like thermo fan, wideband close-loop, boost control, etc.

V.3 board with MS2 ECU would be more than adequate. build-your self the kit from $266 USD, built kit from around $420 USD.

Given that you are stuffing a lot of boost into the engine, you will really want ECU control of the spark (for boost retard, soft/hard rev limiting, etc). Plus, you'll have the sensors there for the ECU anyway, so spark control is only a bit more wiring.

If you can, get the EFI dizzi and use the 4-tooth wheel inside it. Saves having to fit a 36-1 wheel to the front of the crank. If you don't want waste-spark ignition, the dizzi's 4-teeth will do fine for trigger signals for fuel and spark.

[RAAAH23]

oh its only goting to be running 6-8psi nothing massive. dont tell the popo but im still a p plater. i saw owens ecu but shouldve acted sooner rather than later it turns out. does anyone have any fuel maps for a 2TG? is that what theyre called? even something like an 18RG seeing as its going to be 2ltr

[oldcorollas]

fuel maps are pretty easy to work out once it'S running..
you get it to idle, then tune around the no-load areas.. then guess the load areas and go point by point... or log it and change batches at a time

MS would be fine, but the fine for getting busted on your P's with a turbo would not be cheap? there goes ya budget


so happy it runs again!!!
tuning for a stable idle with fuel and spark is a bit more tricky than i hoped...
narrowed it down to the 1000-1200 region, with around 70-80kpa...
i'm trying to put stabilising "humps" in fuel or spark to try t reduce the surging(?) but so far not much luck

but it free revs cleanly and quickly, even just using ond settings and random advance (maybe 20-30?)

i'm finding setting the trigger offset is not easy, as it likes to idle around 30deg advance.. and there are only 20deg of markings on the timing cover it'S reasonably close now so im not going to get hooked up on the actual numbers in the timing table.. just whatever works

[RAAAH23]

true true but if you dont drive like a tool and dont give them a reason to pull you over then the chances of getting caught are significantly lowered.

[thechuckster]

stu: just put the trigger angle roughly or 30 or 40 BTDC, put same guess as trigger angle offset, set fixed angle to 20 (or the whole ign table, afterstart settings, etc), put timing light on #1 then just keep changing trigger angle offset until you get that same 20.

Don't worry about the exact crank position of the sensor. Dizzy will hapilly arc for all kinds advance figures.

[oldcorollas]

thanks
heh heh, thats prety much exactly what i did... except that it ran like shit on 20 and had to up to 25-30, which is off scale.. still is probably within 5deg or so in the end.
i ended up finding it a bit easier to set the timing to 25ish, set the trigger offset to 20ish, and then rotate the dizzy while running to make timing light match...

i'll re-mark the "minus 20deg" mark i put on the pulley and see how close it is.. the idle is reasonable now, so should get some sense from the timing light.

yeah the rotor tip is quite wide, i figured i should put it roughly in the middle of the range of spark needed... whatever that ends up being

really happy the wiring and stuff is ok.
not so happy that randomly lost rpm signal on a restart at some point.. no real reason i could see.. just hope it never happens again