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My e-fan has never worked when triggered from the MS. I had it on a manual switch but hated it due to all the shortcomings, so decided to start digging into making it work.
I saw on the software side that IAC1 was disabled on the port output settings, so I set it according to Aaron's guide (it is also wired as in the guide, with the DIYAutotune harness). Nothing. I pulled the ECU to check if S12C was jumpered to JS9 like distr0's problem here. It was not (that thread threw me a curveball though since it says S12, not S12C. Thankfully the megamanual specified.) so I put a jumper.
I reinstalled the ECU and set it to activate at 85 so I could verify it turning on with MS control, but still nothing. Am I missing something else?
This ECU is actually one that was built for me, so I'm wondering if there is something else missing needed to operate the output. I do have some build notes on it and can always pull it back out to verify what all is connected and where.
Yep empty proto. I'll get the parts and wire it up tomorrow, hopefully that will do the trick. As a side note, when this ECU was first installed to my harness the BAC was connected, but it would quickly get hot, hence not having it right now. Would not having the BAC mod done to the board cause that? It would be nice to get the BAC working again.
The BAC was getting hot? If the BAC was hot, then the coil was energized 100% of the time with 12V. Since the BAC mod was not done, then it stands to reason the drive transistor was burned out instantly and is a short to ground.
Or there is another wiring issue.
The pullup resistors for the LEDs look extremely messy. For appearance and longevity sake, I suggest you move them to the bottom of the board as shown in my writeup.
Yeah, those resistors are none too pretty. I'll move them when I do the fan mod. I'll also put a new transistor in just in case it did burn out.
I was looking through the box of spare parts from the MS build and found a second build sheet hidden under piles of empty parts bags. Not sure if it will affect anything but figured I'd put it up here since it is related to the IACs.
It is only for the IAC2 outputs though, so I wouldn't think it would affect my fan operation on IAC1A.
If you want to run the BAC you'll need to perform the BAC mod, not just replace the transistor. The stock transistor (basically a 2N3904 / 2N22222 equivalent) can't source the several amps required by the BAC.
Okay, so I pulled it out today to do the mods and move the resistors. When I flipped the board over to put the resistors underneath, I found that the hookup wires are done differently from yours.
Where yours are:
D16 to IAC1A
D15 to IAC2A
D14 to IAC2B
Mine are:
D16 to IAC2B
D15 to IAC2A
D14 to IGN (near DB37 on circuit board)
IAC1A is not connected to anything
IAC1B is connected to the center +5V in the top of the proto area.
Before I move further, should I change these hookups around? The car was running decently as far as the leading coil, the rest not so much.
Thanks in advance Aaron.
Edit: For clarity in case it matters, I am not running the CAS for ignition. I still have the housing and shaft, but the top gear has been replaced by a 12-1 running with a hall effect sensor reading it.
I mistyped there, your page says D16 to IAC1B, not 1A.
I went ahead and did the e-fan and BAC mods, except for I didn't have any spare 4.7k resistors so I will get some tomorrow and finish the resistor relocation. I also changed the IAC wiring for the coils to match yours. Then I'll give it a shot and hope for running engine and fan.
I wonder if the IAC difference caused the strange timing issue initially. When the ECU was installed (CAS was at factory position) and the MS was put to -5*, the ignition was nowhere near in time. They ended up using a degree wheel and a borescope to put it to -5*. I later got it firing where it should on factory marks by changing the tooth #1 angle. Would the IAC trigger wires being switched have caused the leading coil to fire when the trailing coil triggered? The car was running on leading only so the split wouldn't be affecting anything.
However, when I turn the key to on (currently have a remote start button on so not using key to crank) the relays go crazy, especially the fuel pump relay. Also the tach on TunerStudio jumps all over the screen. I turn the key off again right away so it doesn't kill anything, but it seems almost like the relays are being PWMed. I will investigate further.
There really wasn't a reason to change the wiring around if the correct point on the circuit was ending up to the correct point on the car. It didn't really matter what order you used the spare and IAC connectors harness wise, as long as internally they are jumped to the correct location and on the harness, connected to the correct point on the car.
However your timing issue makes me think they had the trailing trigger on the leading or something silly. Best confirm that each point on the Megasquirt circuit leads out to the correct point on the car.
As for the new issue, does the ECU run correctly on a Stim?
That is what I was wondering about them having the triggers messed up or something.
Unfortunately I recently moved and have not yet found the Stim. However, I switched the jumper leads back to how they were but kept the BAC and fan mods (and resistor change). Now it is all back to normal, but with functioning e-fan. I haven't tested the BAC yet as I didn't plumb a port in last time I changed my intercooler piping.
I'm pretty sure it is all working as it should be, but didn't get a chance to test drive it yet as it started as soon as I got the MS installed and cranked it. My plugs are fouled but I have fuel pressure, my MSD is pulsing, as soon as it stops raining and I throw new plugs in it should be ready to drive around.
I did verify that the leading and trailing coils are connected to the proper pins at the ECU. I suspect that they just didn't stab the CAS correctly after they changed out the trigger wheel on it. Either way, it is running fine for now and I will make sure the trailings are firing when they are supposed to be before I put them in for good. A big issue there is finding room for the coils. For as much space is under the hood, there is not too much that is usable.
Thanks for all the help Aaron! Without your guide I would have never tried MS in the first place.
Not stabbing the CAS correctly would definitely do it. Easy mistake to make and we've all done it.
One thing about the Megasquirt of course is that there are so many options to configure it. As in, whomever is setting it up can make their own decisions as per DB37 pin functions. Different methods aren't "wrong" per say, but can make it difficult to compare with other setups.
Yes, that is definitely something I am noticing as I learn more about the Megasquirt. I am happy to say it is running fine now, except for the turbo seal that just decided its job was too difficult. ECU-wise though, I am a happy camper.
On a similar note I am using a two-speed fan. Currently I am only using the high speed, but I'm thinking I could use that spare ignition output (pin 36, brown on the DIY harness) to control the low speed. Would I have to make a similar circuit on the proto area for that? I have plenty of space left over since I have a hall effect setup if that is the case.
08-31-16, 09:44 PM
