The MegaSquirt Project has experienced explosive growth other the years, with hundreds of new MS installations occurring every week - a phenomenal success! MegaSquirt has been successfully used in all aspects of Internal Combustion engine applications including R&D, Industry, Race, and Research. The MS project has transformed itself from a simple R&D project into a full-featured mature engine control system. To reflect this the support structure has also changed to meet the needs of MegaSquirt Users.
Moving forward, the R&D forums for MegaSquirt project are in a read-only mode - no new forum posts are accepted.
However the forums will remain available for view, they still contain a wealth of information on how MegaSquirt works, how it is installed and used. Feel free to search the forums for information, facts, and overview.While the R&D forum traffic has slowed in recent years, this is not at all a reflection of Megasquirt users, which continue to grow year after year. What has changed is that the method of MegaSquirt support today has rapidly moved to Facebook, this is where the vast majority of interaction is happening now. For those not on Facebook the msextra forums is another place for product support. Finally, for product selection assistance, all of the MegaSquirt vendors are there to help you select a system, along with all of the required pieces to make it complete.
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Bruce Bowling wrote:...
Sweet Now go hook up 'them coils
- Bruce
was going to today, then figured out that i just don't have the right combo of ends for the plug wires to make it work. this motor needs some pretty deep straight boots into cyl head. i'll have to order something.
in the meantime, i'll try to see if i can't figure out ways to turn the problem on/off.... either through changing offset, or advance table, or?
This weekend I spent the time trying to make the code more robust against missing pulses, but I haven't yet tested it. After that I will see about setting a very large dwell or small advance or whatever to make it fail. I then want to see if it screws up the ordering of the outputs.
sounds great. i look forward to hearing how it goes.
one thing that i recently thought about, is on my Pontiac. at one point, i discovered that my dwells were crazy during cranking. then, if i disconnected the MAP sensor, the problem would go away. so this made me think it was hardware/noise related.
but... it's possible that this phenomenon was happening due to the coding.... in order to unplug the MAP sensor, i had to sort of hard code a fixed map value in the 2 point sensor settings. i can't recall what that value was, but it makes me think that my hard-coded (map unplugged) put me somewhere else on the spark advance table so that either the beginning or ending of dwell was lining up with something else, and creating a bad condition in the code.
Bruce Bowling wrote:
Sweet Now go hook up 'them coils
- Bruce
fired right up with individual coils. sounds EXCELLENT, even without fine tuning offset or tuning idle advance. did some driveway dragstripping and it is really nice. no cutouts, backfires or whatever. i'm a bit reluctant to fine tune the offset, or change any advance table settings until we discover what the conditions are that are causing the phase shift.
another thing worth note.... when putting in these coils, i removed the stock AFM in place for a straight tube, and idle revs went up by 1000 (from 700 to 1700). had to crank down the idle adjust quite a bit.
we've got some things going on today, but hopefully set her to sea this evening and finally get a real road test running ign.
still wasted.... i'll cut off some reluctor teeth from distributor after a successful road test and go sequential.
TheMonkey wrote: i'm a bit reluctant to fine tune the offset, or change any advance table settings until we discover what the conditions are that are causing the phase shift.
I have been testing the code for the last 2 weeks using your msq with all sorts of bad configurations and I haven't seen any problems as long as there is solid tach. If dwell is too long/ rpm too high, it reduces dwell in proportion to the dwell and spark durations you have specified, as it should. If trigger offset/ delay teeth are wrong, it sparks at the next tach pulse, as it should. I have run 6-cyl up to 14000 rpm, no problems.
A problem I did see occurred when I tested missing teeth due to signal dropout. This caused double ignition outputs per 360 deg, but only when a tooth was missed on a tach pulse. No error checking was being done on tach pulses, because they already take a lot of time. I fixed this so the code is now more robust (but possibly a little lower max rpm). But you still have to have a decent tach signal to maintain synch - it can't be random.
I took the car out today for some test driving. I am amazed at what a difference this new ignition system has made to the car. All around power, smoothness, and better idle. I drove around quite a bit in a lot of conditions and had no problems. In fact I started driving the car really hard because I was having so much fun and blew a hose in the cooling system. I'll get that fixed and keep going forward with testing. I'm now anxious to pull in the cam sync for sequential. I'll have to do some tweaking to fueling because I'm sure the opening time of injector is not same between wasted/seq. I'll do the same routine I did on my Pontiac to find the opening time to match wasted/seq, and adjust fuel map accordingly.
Al-
on the phase shifting....
I'm pretty confident you guys will find it when you get a sequencer hooked up to a motor. I had these same symptoms on the Pontiac but was not able to find as much info as this since I couldn't run just fuel first.
Anyhow... the KNOWNS for me are that on the BMW.... Depending on delay teeth and offset settings, I have weird signals including phase shifting (fuel and ign). It occurs on different points of RPM band depending on the delay teeth setting, and I seem to have a found a setting to avoid the symptom all together. This is a repeatable situation by adjusting delay teeth... like turning on a switch.
Unless you want me to dig any deeper in the meantime, I think we should just wait to see if it happens when you guys hook it up to your motor, and I'll just keep my settings where they are.
I'll post back when I pull in the cam signal.
Bruce- any progress on getting your wired up to your motor?
I should mention a couple things I did in this setup...
As a general rule, for cleanest ignition power, I usually wire directly to battery with a large capacitor (I use MSD PN 8830). I did NOT put this capacitor in, and it seems to be fine. In fact, I wired power for coils through a fuse holder to the original power source for the single coil (before the balast resistor), where it also T's off into a couple other things. Ground for ignition went to block, and so did the ground for the small current logic signals (rather than to signal ground - BB suggested this is sufficent and even preferable in some situations). I haven't looked at it on the scope yet, but it seems to operate just fine.
I still have a high quality stereo filter on the power feeding the sequencer. I'll try pulling that off to see if sequencer is still happy without it.
My grounds from Sequencer unit (both ends) are over-wired, and soldered, and lugged at block.
So, the only thing unusual with the wiring has been that I needed to insert a resistor in series on the VR crank trigger which is an OEM wheel and sensor from later BMWs. This same wheel and sensor generally does not need a resistor on the MS 3.0 board.
how large of a voltage signal does the VR#2 cam sync need to be? i'm having a hard time with sync. i rigged up a temporary setup and getting about 0.9v swing peak-peak.
TheMonkey wrote:how large of a voltage signal does the VR#2 cam sync need to be? i'm having a hard time with sync. i rigged up a temporary setup and getting about 0.9v swing peak-peak.
The second VR channel is purposely set higher because most installs use a hall sensor for the cam sync. The trigger voltage is about 1.9 volts.
You can "bias-up" the VR2 return leg to a higher voltage - this brings up the DC level and may help out. Its easy to do - make a voltage divider between Vref (5 volts) and ground with two resistors and use the mid point as the VR- return path. So if you do this combination:
it should bias up the point to about 1.6 volts, so a 0.3V rise in the VR2+ line will trigger the second VR tach circuit.
Note that what you are doing is making a new ground point - do not connect the VR2- point in the resistor network above to the VR- signal on the other sensor (VR1)...
Now go hook up 'them coils
