Help! Unsuccessful first attempt!
 

Ok, I got it all wired in, but it wouldn't fire. There are some obvious things to go after, but some not so obvious. First off, Al, I tried your .cas file and it came up with an error message about an audit and 493 warnings or something like that? Don't know what that was about. I loaded mine again and didn't get the same message.

Sensors: after all that messing around with EasyTherm, the coolant sensor was reading 60 and the IAT was reading 90. Ambient temp in my garage was probably 80? I am using a GM IAT sensor from the intake tube of a LT-1 Chevy. When it warmed up (running on OEM computer) the CTS was still 30 degrees less than the reading from my infrared temp gun aimed at the thermostat housing. When I shut it down, the IAT read 113 and my temp gun on the intake tube read 111. I have read threads about people having problems running the OEM sensor, should I switch to a GM sensor?

Ok, here's the big one. I am not reading engine RPM when monitoring it with the OEM ECU running the engine. I suspect this is why it won't run. I used a 1K Ohm resistor off the ignitor, even though everyone else is using the CAS. Sorry, but I don't know if I'll run spark with mine, and I can't find clear board mods for the V2.2 board and the 1.6 engine that make me feel confident enough to do this. Can anyone help? Should I proceed with the ignitor and add another resistor? In series or parallel?

Also, for more information, while running it on the stock ECU, the MAP and temp gauges were working, the O2 indicator was not.

Thanks in advance for any help you can provide,
Kyle

The warnings come up because it was made with an old version of the MS code. It won't work.
Which wire on the ignitor are you connected to? It should be the yellow/blue wire labeled TAC. The resistors are only so the stock tach isn't killed when the MS is connected. It should work in megatune no matter what.

Check your connections to the factory harness, and check your soldering on your DB37 connection. The different temp readings under different conditions suggest a short in there somewhere.

I'll check the DB37 tonight. I was hooked to the TAC wire of the igniter. One other question. In the settings sticky, there is a screen for cranking settings. Should that be in my version of MT?

Yep, the cranking settings should be there.

Make sure that you have Megatune 2.25 on your pc, then get MSnSE 029q2 from the Extra website. Unzip 029q2, open 'Edit Settings', change the default to # set MSNS_EXTRA,

choose your O2 sensor (do the same thing, # set..., and have the rest #unset...)

Then click on File > Save

Then exit 'Edit Settings'

Then use 'copyini' to copy the current version of MSnSE into the MegaTune2.25 > mtCfg directory.

Then you have to open EasyTherm, change the settings to the ones you want for the temp settings, click on 'Custom' in the Code Version box, change the port to the correct port for your connection, then click on Write .inc and .s19Files, then click on Download to MegaSquirt.

That should get the files set up. If you want a N/A setup then I can send you my .msq if you send me a pm with your email address, and if you are running a turbo setup then one of the other guys can help you out.

Oh boy, you guys are going to get me running spark after all, aren't you? I'll try that tonight. Thinking more about what you said about different temp readings under different conditions, I'm not sure that is the case. I think I could say that the coolant sensor was consistently 30 degrees below the actual coolant temp. Does anyone know what problems are associated with the OEM sensor when people say they don't have good luck with it?

Aussie, I can't send you a PM until I have 10 posts. This will make 8.

9.

10!

Are you sharing the IAT sensor with the factory ECU? If you are, you need to leave out the bias resistor on the MegaSquirt as the bias resistor is present inside the factory ECU. Here's a couple of pages that might be of use:

http://www.megasquirt.info/v22manual/sharesen.htm
http://www.msefi.com/viewtopic.php?t=19473

If you find out what the bias resistor value is inside the ECU, it would be good if you could post it back here so we can all benefit.

Good luck!

Nope, I'm using a GM IAT because it seemed that was what most of the threads I read were doing. That and using the stock coolant sensor with R7 changed to 2.2K, as that was what I read on the megasquirt forum. Though now reading Greg Salt's thread it looks like he had some temperature error as well, but it didn't affect him either. I did everything Aussie said, so now I'm running MSnSE code in MT. Last thing about coolant temp, I played with the values in ET quite a bit and kept rewriting the .inc files. The coolant gauge didn't change. But honestly, the coolant temp is the least of my worries.

I checked my wiring. Everything is hooked up according to the MegaMiata Pinout.pdf file pulled from MS forums. TAC is hooked to pin 24, power to 28 (with a 3 amp fuse...enough power?), I've got power, temp guages, and the MS works with the stim. The only good thing that happened tonight is that my 1.8L injectors arrived and I got those put in. Ahhh, wrenches are so comfortable......

I'm still running the factory coolant temp sensor. I haven't modded the board (I'm going to run the GM sensor when I do my coolant re-route) but by using Al's temp settings with EasyTherm, it's reading accurately enough that I'm getting reliable first starts in 4 degree C morning temps.

Make sure when you load the 'new' file onto the MS with EasyTherm, that you choose the .s19 _mod file. Otherwise it will just load up the original unmodified file.

(Don't ask me how I know that.......)

So are you saying you are still running the original 2.49K resistor? Maybe I should put that back. What is this coolant re-route you mentioned? I am looking for better cooling, it was running pretty warm on the track Saturday. My EP Miata had a very different coolant routing that the SCCA guys claimed ran much cooler, but I didn't find anything about it on Miata.net's garage, which surprised me. I've got a new radiator on the way, but I'm always interested in coolant system improvements.

(I accidentally posted this in my other thread, it belongs in this one.)

Major progress last night. I wasn't reading spark because I was only using the jumper from XG1 to XG2 for using the stim. I was finishing assembly on the other MS I almost had built and going through the assembly process brought me to that decision point on the board and in the past I guess I hadn't planned on running it the way I am right now. I also put the 2.49K resistor back across R7 and my CTS is only about 10 degrees off. Close enough! So I'm reading spark when the OEM ECU is running it, but as you have described, the OEM tach doesn't work. I never got an answer, should I put more resistors in series or parallel?

Aussie, I tried your .msq file, and it says there are 20 warings to the audit file. Any idea why thiss would be?

So I tried running it on MS. It fires, revs, then dies. Revs then dies. But it's running fuel and spark when it does that. I increased cranking fuel by 50% but it didn't help. It's like it really wants a TPS signal, because it doesn't respond at all to the gas pedal. Any more suggestions?

Getting closer,
Kyle

The Megasquirt doesn't need a TPS sensor.

What year is your car? How do you have the fuel pump output connected?
Is the Megasquirt reporting correct RPM readings in the software?

Hmm, I have done nothing with regards to the fuel pump. The pdf I was using with the connections I need to make said the fuel pump relay connection was not used. Shouldn’t the stock ECM be taking care of this? I hope I'm wrong. No fuel pressure could certainly explain what it's doing.

I have been scouring threads/DIYAutotune's site to make sure I'm clear on how to make the board mods on a 2.2 board. Does anyone know of a clear thread/link that could help? Also, my Radio shack only had 1/2 watt 470 ohm resistors. That just means that they will disapate more heat right? Should that affect anything? Half a year ago I bought an EDIS set-up thinking that's what I would need to do to run spark. Maybe waiting paid off, it would be great to be able to use my stock ignition system.

Thanks,
Kyle

Oh, and to answer your other questions: the car is a 1990, and the rpm is reading 1700 at idle. It is idling high, but I'm not sure if it is really 1700. I haven't added another resistor to the TAC conection yet to try to get my stock tach working again to find out.

I would guess those resistors will work fine. Your fuel pump should run normally if your AFM is still connected.
Get that 2nd resistor on there and everything should work.
If it fires and dies, check that your after start enrichment table has acceptable numbers in it.
Asfor the mods, just use the picture on diyautotune.

Do you still have the AFM connected? The AFM has a switch that controls
the fuel pump. You need to take a realy and jumper two of the wires together
to turn on the fuel pump.


Check the forums for my thread on Miata VS Megaquirt. It has all the info you need for the 2.2 Board

AFM is still hooked up. I would love to get rid of that thing. It probably isn't the fuel pump. It would appear that the picture in DIYautotune site for the 2.2 board isn't there anymore, but I followed these instructions:

<-How to mod a MegaSquirt-I PCB2.2 ECU-

Parts Needed for Input Mod: (1) 1k 1/4w Resistor and (2) 470 ohm 1/4w Resistors (Just ask me for them when you buy your kit - free!)

"CMP Signal" -- Lay a 1k 1/4watt resistor across the bottom of the PCB with one end at pin 11 of the processor (U1) and the other end at the X11 hole. Bend the resistor leads to raise the resistor just a bit off of the PCB and allow a lead on one end to drop through X11 and solder that end in place (while making sure the other end is in place near pin 11 still, and with the resistor still raised a bit off the board so the leads don't short against anything). Then use needle-nose to hold the resistor lead to pin 11 and solder it to the pin. Now to get the 5v pullup use a 470 ohm 1/4w resistor and solder one end of it to the first resistor at X11 (just tie them together) and the other leg of it to the small un-labeled hole just above and to the right of D9 (when looking at the PCB from the top that is). Once again raise this just enough off of the PCB to prevent it from shorting with any of the leads sticking out on the board. (Heatshrink tubing over the whole wire/resistor assembly works nicely)

"CKP Signal" -- We just need a 12v pullup. Install a 470ohm 1/4w resistor between the right side (non-band) end of D5 and the right hole (banded) end of D9.>


I hooked up the blue and yellow wire off the CAS to pin 24 and the white CAS wire to pin 11. I tried to load Aussie's .msq and got the same 20 warnings to the audit file. This time the original ECM won't run the car. Unplug the DB37 and it starts. Grrrrrrrrrrrrrrrrrrrrrr!

try this.

To get the CAS to work correctly I used a 470ohm 1/4 watt resistor and soildered one end to pin 3 on the map sensor (5v) and the other to the CPU pin 11. Then I ran a wire from CPU pin 11 to X11 which goes to pin 25 on the DB-37 connector.

I also took a 1.2k 1/2 watt resistor and soildered one end to pin 28 on the connector and the other to pin 24.


Run 12v, ground, and the Y off the two cas signals to the megasquirt.
Start the car and see what the tach does on the megasquirt.

All right, I shouldn't have missed that, it was early on in the Miata v Megasquirt thread. I went too far down and followed the link.

OK, so I made another big step. Did what you recommended, added the 470 ohm resistor and 1.2K ohm resistor. Wired the white CAS wire to pin 25 of the DB37 connector. The stock tach works again, and MS reads 1/2 the rpm of the engine. I still get the 20 warnings with Aussie's .msq file, but I loaded it anyway because it wouldn't run with mine. It started, and if I flickered the throttle carefully I could keep it running. Not correct, but more run time than I've had yet.

Maybe I'll build the second MS to this point to rule out a damaged board?

Still kicking,
Kyle

Your probably have it set for a 8 cyl if it reads 1/2. Goto the config page and make sure its set for a 4cyl. You should check the log file to see what the warnings are. Finaly I would reflash the megasquirt to the newest extra and start from scratch. You can manualy copy the setting out of the other log file.

The warnings were a units thing. I changed my units to Celsius to match the .msq file and the warnings went away. All my settings match the settings on the settings sticky exactly. Yet I have to change cylinders to 2 to get correct rpm in MS.

You could go ahead and set it up with the board mods to run both CAS signals in wheel decoder mode. I really don't understand why you would be reading half RPM.

Al is right you should be running both CAS inputs into the megasquirt and running in decoder mode. That will fix your 1/2 rpm problem.

So there are additional board mods to be made for decoder mode, or do you mean the input board mods I already made and just check decoder mode?

No, the mods you've done are all you need. Just connect your secondary tach wire to the secondary CAS signal.

I'm assuming the outer (blue/yellow) CAS wire is primary and it is hooked to pin 24. If the inner (white wire) is the secondary, it is hooked to pin 25. I reloaded MSnS last night. Nothing changed. Should I be posting to the MSnS forum? Will the board mods I made confuse the situation? Man, I can't believe this. The longer these problems take, the more you know it's going to be something stupid. I'm looking through the assembly checking for things that can change based on application. Did you guys use diode D8? Any other ideas?

Dem wires are backwards. White goes to primary tach, blueyellow goes to the secondary tach you added with the input mods.

Where do the terms primary tach and secondary tach come from? Is that MS terminology? Regardless, white to 24, blue/yellow to 25? It's going to be another one of those "I can't wait to get home to try this" kind of days! Thanks so much. :bowdown:

Al, I was going to say the same thing. There are 1/2 as many holes in the inner wheel as in the outher 2 vs 4. Hence 1/2 the RPM. Fulltilt you should
be ready to rock once you get the wires swapped.

So the translation of that last email was, it runs on MS! Pretty good actually. Slight stumble, but not as bad as I would have thought, and it's not tuned yet. Now I'm on to datalogging problems, but there are a lot of things over on MSEFI.com that I can try. You guys have been very helpful, thanks so much! :bowdown:

Kyle

If you have your 02 sensor hooked up. Check out the autotune feature
in Megatune it works well for everrything accept Wide Open. That or an LC-1
would get you spot on.

I got autotune to work and it roughed me in. It was great! I am using a DIY WB. Not long after, something started to go wrong. My A/F spikes to 30 or 40 and stays there. I am suspecting the WB, though certain changes in MT tend to bring it back in temporarily. I'd drop the $200 for a LC-1 if it wouldn't hurt my pride so much. I spent months building that kit years ago!

Since I'm close, I may just put the NB back in and tune it through logs. What bums me out the most is that I had just gone out on the OEM ECM to find out what the stock A/F was at WOT. Does anyone know that? I need to get to a dyno and tune it right, but right now I am just using the standard target A/F chart.

My logs show 16-17:1 real briefly on accel. I dialed in a bit more AE. Turns out I was using RPM based AE, probably because I started with Aussie's .msq. The help file in MT says only 99.9% of all applications will use RPM based accel, yet discussions seem to suggest that it's more accurate. I guess since it runs pretty good on it, I should just run with it, right?

It isn't lean on WOT, I think I'm almost ready to run it on MS at the racetrack!

As long as its around 12.5:1 at WOT you shouldn't have to worry.

I can't decide if this is a dumb question and I'm missing something fundamental. If I'm using a NB sensor and the VE table is set to run my car more rich than 14.7:1, is the NB really doing anything, or am I just always in open loop?

The NB is only accurate around 14.7 but the MS treats the input the same as a wideband. So, you could get yourself in trouble tunning WOT with a NB sensor. Its fine for crusing and idle though.

Contrary to the popular belief, a narrowband can be very accurate and repeatable at the top of its' curve and can be used to hold an AFR of 12.5 very nicely. It is a chemical reaction and the curve is not nearly as steep at the top.:bigtu:

This is not necessarily true of "NB Simulators" provided by some WBO2 manufacturers.:ugh2:

http://mymiata.paladinmicro.com/Miat...tm#O2SensorHow

Would it be possible for you to list out your final wiring setup? You have 25 going to blue/yellow, while kags has it going to black/white. Will either one work, or is this a difference between the v2.2 and v3 boards?

Sorry it took so long to reply, been outta town for a week. I hooked white to 24, blue/yellow to 25. Don't know about a white/black.