Ign. timing going out of sync., I think!

[nolzzee]

MS2, 3.57, 2.888 firm w. I have had he MS installed and running for over 1yr. running fuel control only. I installed coil driver cir. and have the car running.
I have a pertronics dist. & coil , no ign. module. My problem is that when I rev the eng. timing gos way past the advace table setting of 18 deg. to 40 deg..
When I let the revs come back to idle its still stuck at 40 deg. and ofcourse thr eng. dies. Its like it goes out of sync and the trig. offset number gets trashed . I have played with ign. settings to no avail. I could use some advise as how to trouble shoot this . I have been away from the forum a long time so please cut me a little slack on the proper protical for asking for some advise. Thanks , Noel

[Matt Cramer]

Do you see the 40 degrees of advance in the software, or just with the timing light?

[nolzzee]

I see it with a timiming light. Mega tune is showing 18deg. on the gauge.

[nolzzee]

Hi Matt, There is somthing else happening that is probably related to this issue. When the eng. is idling (using a timing light) the timing seems to be fluctuating +and- 4 or 5 deg. around the set timing. I checked the dist. and it is mechanically locked so that it wont advance.

[Matt Cramer]

Please post a copy of your MSQ and more details of how the ignition input is wired up.

[nolzzee]

Hi Matt ,my MS2, 3.57 has R57 and D1 & D2 installed. The Pertronics dist. (Hall E) has 2 leads, one is connected Ign. 12v , the other is con. to DB37 pin 24. and ofcourse DB37, pin 36 to coil neg. terminal. I have attached my ms tune. I do have a scope if we need it.

[Matt Cramer]

Try changing the triggering to Rising Edge and see if that has any effect. You'll need to adjust the trigger offset when you do this.

[nolzzee]

I have allready tried diff. trig. edge. Im thinking maybe I should go with a trigger wheel set up and forget the dist tach. signal. With a trig. wh. and coil driver cir (no ign. module) it should be fine. What do you thnk? I dont need ign. module if im using the coil driver cir, right?. Thanks matt, looking forward to your response.

[Matt Cramer]

Correct, you won't need the Pertronix if using a crank trigger. And a crank trigger is considerably more accurate.

[Bernard Fife]

it goes out of sync and the trig. offset number gets trashed

nolZ,

In addition to what Matt says (which is good advice and all correct), you may have a serious communications issue. Nothing that normally happens at the MS-II should scramble the trigger offset value in TunerStudio.

There are a few ways I can think of that would do this:

- Powering down MS before a flash burn has completed. When the RAM memory is burned to flash memory (made 'permanent'), it has to erase a large chunk of it, the write it one byte at a time. If the power is shut off during this process, a number of values will be filled with 1's, so a one byte value will become 255, etc. TunerStudio might than limit these values (to 40, for instance), but it won't be what you entered originally. So you want to wait a bit (a few seconds, at least) after making any changes to power down MS-II.

- if your PC is sending garbled values to the MS-II, then MS-I will go ahead and use them. Most of the checks are done in TunerStudio, not MS-II. If it only scrambles the trigger value at higher rpm, then you might need to shield the serial cable from interference.

- the INI is incorrect or corrupted. You might want to reload it from the source: http://www.megamanual.com/files/ini/

Lance.

[nolzzee]

Thanks lance & matt. I have decided to go with a trigger wheel, once I get that finished and running I wand to upgrade to coil packs and no distributor.
One ? DIY, sells Hall efect sensors and say that they run them threw VR input. I dont get that. If they are a Hall effect , where is the flying magnet??
Regards, Noel

[nolzzee]

Lance , if I rebot the ini should I up date it to A newer version? Im at 2.88.

[Bernard Fife]

nolzee,

I would use 2.905 from here: http://www.megamanual.com/ms2/code.htm It is similar to the 2.888 you are using, but has some fixes and a few new additional features. More importantly, it is very well tested and is stable.

Lance.

[trakkies]

Thanks lance & matt. I have decided to go with a trigger wheel, once I get that finished and running I wand to upgrade to coil packs and no distributor.
One ? DIY, sells Hall efect sensors and say that they run them threw VR input. I dont get that. If they are a Hall effect , where is the flying magnet??
Regards, Noel

It's common to have a tiny magnet built into the hall effect sensor with a slight gap between them. It will then read a toothed wheel, etc.

[nolzzee]

AH-HA, now I get it. thanks for the expanation.