My experiences with Megasquirt

[480sx]

Really, i never had any issues with my thermal fast idle, it worked fine. Are you sure your problem cant be traced back to warmup enrichment?

What about startups? I could never get past the cold start up kick backs. Were you able to rotate your dizzy to a less advanced position, and set your trigger angle up enough to eliminate that problem? Whats your trigger angle set at i guess would answer my question too..

[krazydriver]

in answer to your question. I have the dizzy set approximately where the factory ecu would idle at 15* advance with my my trigger angle set to 106.

This works fine for me as far as a good starting spark, and my timing is dead on once the car is started.

[2projects2many]

Hey Zig, or any other Megasquirt gurus- I'ts time for me to start my newly rebuilt KA24det. I was out there messing around and discovered I'm getting no crank signal. I wired everything according to the DIY write up and I'm using stk coil (but that doesn't matter right now) but I'm getting no cranking rpm's. Any ideas please?

[480sx]

Did you wire in the correct resistor to the tach signal wire, and use a 12 volt pull up?

[2projects2many]

I wired 12v to the b/w wire, have a 1/4w resistor coming from another 12v source to the white wire going to pin 24, and than I have a black wire going to ground.

[ZiG]

I wired 12v to the b/w wire, have a 1/4w resistor coming from another 12v source to the white wire going to pin 24, and than I have a black wire going to ground.

Ok, you say 1/4 watt..

I wired 12v to the b/w wire, have a 1/4w resistor coming from another 12v source to the white wire going to pin 24, and than I have a black wire going to ground.

but what's the resistance? Is it 1k? Did you make sure with a multimeter? It doesnt have to be exactly 1k, but fairly close..

[2projects2many]

Zig, it's exactly what the write up said to use. I know I am getting 12v on both wires at the distributor the B/W & the white. Is this correct?

[ZiG]

Hm, sounds right. Is your wire shielded all the way down?

[2projects2many]

No Zig, I removed some of the wire shield in order to solder to ms lead- It goes as far as 3' from the ms, but I figured that it wouldn't matter much it's only for interference- I should still be getting a signal clean or dirty. Now I'm wondering if my ms is screwed or not setup correctly to receive an rpm signal. I notice that I'm getting no duty cycle on inj either. This may be because I have not tach signal though.

PS. is the shield the negative wire that needs to go to ground, or the other blk wire?

[krazydriver]

shield is the wire that goes to ground. The other black wire is a second CAS output that megasquirt doesn't use.

Have you checked your MS with a stimulator? That might be worth doing.

[2projects2many]

Krazy, I did previously after building for fuel only. Now that I've made the mods to drive the coil, I don't know if I missed a step or something because it used to pickup the signal when pulling from coil. I'll just have to take it apart tomorrow and retrace my steps. From what I've read- you can't test the rpm's off the stim when setup for Optical pickup- is this true- 'cause if so, I won't be able to tell anything anyway. Thanks for the help guys- if you have any other info to provide- please do so- I want to be running again!

[krazydriver]

if that works before the megasquirt itself is probably set fine. You can test the optical tach input with the stim( the only one you can't test is VR), BUT you must undo the 12v pullup or it stops working... not sure why.

Kinda simply, but did you make sure you changed the tach input setting in megasquirt?

Should be set on basic trigger, Input capture set to falling edge. It should be piccking some kind of signal up.

[ZiG]

Oh yeah, good thinking Krazy.

[2projects2many]

I must be all jacked up, I'm running MS1 Extra 029y4, and I don't even see a setting for that. What code are you guys running?

[krazydriver]

ooops! should've asked earlier. I'm running MS2 extra.

i'm not really familiar with ms1 extra. I'll look over the megamanual and see if i can find anything to help you though.

Alright here's what some searching found.

Using the MS-I PCBv3 with MSnS-E firmware

* This is assuming you are starting with an ECU built up like I build my assembled MS130-C MegaSquirt-I PCB3.0 units. If you are building your unit up from a kit you can implement these changes during assembly. * Flash ECU with MSnS-E version 029v or later. (How? Click Here.) (Or Here) * Jumper IGBTOUT to IGN to send to IGBT ignition coil driver signal out of pin 36 on the DB37. * Cut out C12 and C30. (Only needed when triggering from the - terminal of the coil, which you are not) * Remove D1 and jumper it, or just install a jumper wire across it's leads. (Only needed when triggering from the - terminal of the coil, which you are not) * Cut out R57 if fitted (this won't be there on my units though). * Get a 330 ohm 1/4w resistor and cut the leads down to about 1/2" at each end. Maybe a bit less. * Tin each end of the resistor with a bit of solder. * Cut a 5" piece of hookup wire (22ga is fine) and strip just a 1/8" or so. Tin the stripped wire with solder. * Melt the tinned wire tip to one end of the tinned 330 ohm resistor tip and let it cool.

* Heatshrink wrap this wire/resistor assembly.

* Use this wire/resistor combo to jumper the 'top' (top as in when you facing the silkscreen side of the PCB, with the text so that you can read it normally) lead of R26 to IGBTIN on the opposite side of the PCB.

So did you do this already? because that would definitely screw up trying to get a distributor reading.

Other thing i can find is this picture of the ignition settings. I would think you need to turn distributor on, turn all the other top code settings off. then set whatever pin you've got wired for the spark output as spark output A.

Just make sure prior to setting this that you set spark output to inverted. i had it set wrong and accidentally burnt out a blaster coil last year.

[2projects2many]

You Rock Dude. I really appreciate the help, this thing has been sitting for about a year with rebuild, etc,etc. It's time to get it on the road. I just read the manual again, and it says to set to this:

Single Coil Direct Drive Output for a V3.0 PCB

These instructions are only suitable for single and twin spark outputs, for more than 2 sparks see the mutiple output section

V3.0 PCB ONLY

Very Important: Set Spark Out Inverted = YES and set the Dwell to around 6.0mS for cranking 3.5mS for Running and 0.1mS for the Minimum Time as a starting point! Also set LED17 as SparkA output in Codebase and Output Functions!! Read the Software manual for more info!!

[2projects2many]

It also says to set "spark settings" to msns distributor and select spark output A as the only spark output.

[2projects2many]

OK, so I have hooked up the shield wire to ground, so I have the shield wire going to ground & the smaller black wire going to ground. I have 12v going in on blk/wht wire and another 12v (with resistor) going to the white wire going to pin 24 on ms. I have adjust all the settings as discussed in previous post as far as msns distributor, spark output A, spark inverted, stec, etc. I'm still getting no signal, so I'm going into the ms later today when I return home to verify all the assembly steps were done correctly for coil driver. I'll post results.

[2projects2many]

OK, so I did find some things I missed when setting up for distributor input.What I had done

c12,c30 removedjumpered optin to tachselectjumpered tsel to optoutinstalled 1k resistor from r26 to igbinr57 not installedhad D1 removed and jumpered.

What I hadn't done:

Jumpered xg1 to xg2

The ms test good on stim, but still no rpm signal on car??

Anymore ideas guys?

[2projects2many]

OK, so I just tested the incoming signal from the distributor, and here are the results:

key on not cranking = .386 vtcranking = .386- 1.4 vt (fluctuating)

Now I'm confused- the fluctuation in the volts tells me a signal is coming to the ms, yet when in megatune- it shows no signal.

Like I said above- with stim- it shows rpms- so that makes me think that I have the board right, yet no signal.

[eazye2000]

Keep at it bro. Kick it's azz..

You are a bigger man than I. I wouldn't have kept with it this long.

[krazydriver]

hmmm.... I'm not sure what the standard dizzy output is supposed to look like, but it's probably something you'd need an oscilloscope to see properly.

If all the MS settings are okay and the board itself is okay and tested out fine on the stim.... Something has got to be wrong somewhere in the car.

I would double and triple check the shielding, power and both sensor returns on the distributor. Just to make sure everything there is good.

Slim chance, but it might be possible that the sensor got damaged if you accidentally connected wiring wrong or something. but idk....

[2projects2many]

You say both sensor returns, yet except for the v3 board setup- everything else says just 12+, signal, & ground. The v3 setup shows 2 wires and says (-) where needed. Do you think I should use that wire instead of just a ground on chassis?Should the shielding go to that wire?

[krazydriver]

Went and re-read everything.Here's a pic of what you should have.

And what you said earlier.

OK, so I have hooked up the shield wire to ground, so I have the shield wire going to ground & the smaller black wire going to ground. I have 12v going in on blk/wht wire and another 12v (with resistor) going to the white wire going to pin 24 on ms.

That little black wire should be wrapped on the end and not connected to ANYTHING! Grounding it when it shouldn't be might be screwing with the signal.

[2projects2many]

I hear what your saying Krazy, but the pick shows a black wire going to ground, but earlier we covered that the larger blk wire (same gauge as wht) was the second signal and shouldn't be connected- so I disconnected that. Now only the smaller blk wire is going to ground along with the shielding.

[480sx]

Have you tried grounding the thick black wire and disconnecting the thin one? Its been a while since i did the MS thing, but the idea of the big(black) wire being a signal wire just isnt sitting right with me. Im pretty sure you have that mixed up.

[2projects2many]

Have you tried grounding the thick black wire and disconnecting the thin one? Its been a while since i did the MS thing, but the idea of the big(black) wire being a signal wire just isnt sitting right with me. Im pretty sure you have that mixed up.

Actually 480, I had both grounded at one point or another- are you saying that you believe the smaller wire would be the second ring output? To me that would seem odd if the the main signal is larger. I don't know, but right now my voltage is down to about 10- so I'm charging the battery because besides that being just to low and barely cranking the engine- I think that may be the problem because the the dizzy isn't getting 12 vt or better and the signal is too weak.

[ZiG]

This is why when I did it, I got an ECU pinout diagram and an ECU wiring diagram. It's a lot easier if you do it right at the stock ecu harness end and then just leave everything else alone.

[480sx]

What were saying, is that we believe that the smaller of the two wires is a secondary signal wire that is not used for MS. When this wire is grounded or hooked up to anything but a stock ecu, it may interfere with the distributor. Its just an electrical unit, hooking it up incorrectly can cause it to stop sending a recognizable CAS signal, or possibly fry your dizzy.

Also with as cheap as you can score a second s13 dizzy you should have a second one to make sure that your problem isnt just simply a damaged CAS.

EDIT - Zig man, its so much easier, cleaner, more reliable to just rewire your whole engine bay. You condense what was originally 2 pounds of wire down to 10-15 strands that YOU know how they were run, how to trace them if there ever is a problem.

[ZiG]

Eh, I like the simple way. Sure I'd love to rewire the whole damn thing, but when I installed this thing I had 2 weeks to get the car driveable. I'm ok with dragging around a few extra pounds of wiring for now. I know you havent really liked/approved of my setup from the getgo, but there it is.