Jump to content
HybridZ

msns just died, no spark. looking for ideas


blake culp

Recommended Posts

Im still pretty new to megasquirt, but i had it up and running pretty well for the past three weeks using mobys base settings posted in the sticky. i just got done putting in a t3/t4 and 450cc injectors got it running again and was in the process of tuning that when i thouhgt i would try using some other peoples msq's who had 450cc injectors. I had my old settings saved so if they didnt work i would just switch back to my previous settings right? nope! i downloaded moblys msq and tried to start my car and it did start although it was really rough and then died. then i reverted back to my saved msq and it still wouldnt run, every now and then it would kick and sputter but definately was not right. Here is what the car is doing now, i am getting no spark. i checked this by pulling a plug and turning the car over and looking for a spark, and by pulling the center coil wire from the distributer and placing it by the engine where it should spark it it was getting power and again no spark. The thing that is weird is when i turn the ignition off it will spark but just once.... i had my four prong gm hei tested and its good, i am guessing the coil is good but i will test it tonight if i can find my manual to get what the ohm readings are supposed to be, But i really dont think it is the coil which would mean it has to be in the megasquirt itself or maybe the wiring. one last thing, the spark angle always reads 0, before when it ran it would ready 5 when cranking, i think, and 17 at idle ,positive about that. Any thoughts?

Link to comment
Share on other sites

Sounds like what I went through. You will need to check the spark signal from MS. First of all, if you are using the FIDLE output, make sure you have a 5volt power source connected to the fidle output. Hook up a small LED to the FIDLE wire, when you turn MS on you should see the LED turn on. When you start cranking, you should see the light flicker.

 

I had a lot of problems with the FIDLE method, because for some reason it was getting 1.2volts off of something else. Basically, it had two power sources on FIDLE and for whatever reason, the HEI module didn't like the signal it was getting - even though the LED came on and flickered like it should. So I used D14 (the fuel LED) to power the spark. You can read about it on MSnS's site. You don't need to do exactly what it says, because the instructions are for a HEI7.

Link to comment
Share on other sites

Here's some more info:

 

It's really hard to test the output if you don't have a LED. But you can test if you're experienceing the same problem as I did. Disconnect the 5volts and then turn on the car and see if you still get a voltage reading. If you do, you'll need to switch over to use D14.

 

You only need one resistor - a 1k ohm. I scavenged for it in an old dvd player, I'm sure rat shack would have them.

 

For a v3 (what I did):

That is the input side done, now to modify the LEDs to driver the output.

Add 1k resistor from (-) of D14 to the right (5v) side of R24

Run a length of wire from D14(-) to IAC1A

 

For a v2.2 (written by mobythevan, it would seem)

Add 1k resistor from (-) of D17 to the right (5v) side of R23

Run a length of wire from D17 (-) to X11

 

But instead of IAC1A or X11, connect to PIN 35 or pretty much any unsed output you'd like. I don't remember what is the negative side of the LED, but just connect a battery to it to find out.

 

Then in MSnS under setup change FIDLE to idle control and then set LED17 to Spark Output.

Link to comment
Share on other sites

something similar happened to me about a week ago - i also use the hei module, and one day the car just wouldn't start. once i got my laptop, i checked the spark settings - somehow the dwell control had mysteriously changed itself! double check that 'dwell control' is set to fixed duty, and 'minimal for hei4' (which seems to work good for me, though my car will also run with the other settings, 50% and 75%), and double check that under 'spark settings' your ignition output is not inverted.

Link to comment
Share on other sites

thanks for all the replys, im still not really sure what happened, i tried to send msns extra to my ecu through easytherm and it did it successfully, but my after i changed my megatune in the settings to msns extra it wouldnt open... Not really sure why because i have the newest version of megatune 225, but anyway, i reloaded regualr msns, manually went through all my vetable, sparktable, constants etc. (didnt use any saved data, period) and it started. All i can think of is if the msq. from mobly for the 450cc injectors i sent to the ms ecu some how corrupted the program and by reinstalling msns i was able to "reformat" the chip and that cleaned it up... who knows.

Blake

Link to comment
Share on other sites

  • 2 weeks later...

It just died again, completly out of the blue. i was running fine, tuning it with my wideband and i pull into a parking lot to tinker with the ve table and while it is idling it died. no warning, nothing. Here is what i know so far, the ms seems to be grounding out the signal wire to the hei. I tested it by a LED and it wont turn on when the car is in the on position or flicker when cranking. the wire is getting power because i tested on the 5v side of the pullup resistor from the tps 5v vref and the light turns on. So for some reason my MS is always grounding the wire, instead of grounding it only when it should be firing. im really thinking about doing the led17 for ignition signal, but im not positive that would solve my problems. Any ideas?

Im running ms1 v2.2 with the newest release of msnsE.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...