MSefi.com read only forum (Jan.15,2018)

MSII running 2.905 was running a 280zx turbo really well. Then it started to sporadically show large advance in TS and would stop running and not want to start. The advance was showing from 74 to 100 degrees of advance. Then it would run again for a while. I tried reburning the firmware and reinstalled TS with no change of luck.
After thinking that the original wiring for the MS might be an issue, the unused IAC wires with stripped ends were loose under the dash, I cleaned up the wiring and ran correct ground wires to the block that had been attached to the body under the dash. Now there is no rpm while cranking and no advance showing in TS at any point although there are values in the spark table.

Rechecked the wiring and checked again after that. Finally hooked up this MSII to my other rig and loaded that project. It ran so of course there was a tach signal getting in but in TS there was still no advance reading.

Not brave enough to put my known good controller in the 2280zx for fear of killing it!

If the MS is getting a tach signal from the other car, you are obviously loosing it somewhere in the first car.

What are you using to trigger the MS?

Ken

The 280zx dizzy, which worked fine until I cleaned up the wiring.


It runs on the hall/opto circuit and has four wires. one is 12v+, one unused, one ground and one signal. They are clearly color coded. The one thing that i changed was that the shield was attached to the same body ground as everything else as well as pin 1 on the DB37.

Where is the optimal ground for this setup? sensor ground pin 19, same spot on engine? elsewhere? Probably not a direct issue but was a question.

http://www.DIYAutoTune.com/jwplayer_vir ... wiring.jpg

reburned firmware and started new project in TS, no luck...

even though the tach worked in other rig thought I would try because Phil said TS only states what firmware sends.

Can you get an RPM signal if you test this MegaSquirt on a Stimulator?

Going to dig out the stim tonight. It's been awhile and I think it needs resistor replaced.
Any thoughts on why TS shows no advance?
It runs my other car so it is getting some signal. But still no advance showing on that one either. And it runs accordingly.
Btw- this is a 82 280zx turbo in a 75. It is wired per the schematic on your website. Does the tach input come from the negative side of the tach or the distributor.
Bummer is right after I installed the daughterboard pur chased from you last week I ran across the tech article on your site. What any particular settings for this motor other than going high inverted and standard coil charge.
It was running pretty well on ms 1 extra before.

What is the correct wiring for using the 4 wire 280zx distributor and MSII?

It was wired to the diagram on DIYAutoTune inside of the Z guys info. http://www.DIYAutoTune.com/jwplayer_vir ... wiring.jpg

But then I found this quote in the megamanual:
"So you CANNOT use the negative side of the coil to trigger MegaSquirt-II because the coil already has timing advance built in, and using it for a timing signal will screw up the total advance severely. You must use the appropriate distributor or crank wheel for your ignition module."

The timing worked well at first and was accurate as adjusted with the trigger offset, but then it started to get really high values. Like 75 to 100 degrees of advance. Which made it not run of course. Then it stopped reporting any advance in TS at all even though the advance table still had the same values. EX; no advance while MSII turned on but not cranking, no advance reported while cranking, yet 15 degrees in the spark advance table.

This was running MS 1extra, so I did the MSII mod from DIY tech article from above. But now I am confused on what the wire from the +coil to pin 24 is doing and did it(I) kill something in the MSII?

I will be trying the stimulator tonight but am really curious about not seeing any advance??? Especially since I ran my other car with this same MSII, it ran and obviously had a tach signal but still did not display any advance and ran as such.

Also: Where is the proper location to ground the - wire from the distributor? engine or pin 2 where the tach shield is?

Thanks, Mark

Repaired the stim and tested the controller. There is rpm adjustable with both pots and all of the rest are working also.

So this seems to conclude that the controller is good. Still wondering why there is no advance showing in TS?

Now testing the dizzy. It must pull a voltage low because there is no signal detected with the LED tester. Will have to add a pull-up resistor and test again. Is this correct for the l28 dizzy?

This is the turbo distributor but there is no module in this vehicle?????

Is this what the 4 pin HEI module upgrade is for? to replace the stock module which was not attached to the dizzy but maybe under the dash of the donor car?

Thanks, Mark

At what point did you wire the coil's + terminal to pin 24, and why?

Matt Cramer wrote:At what point did you wire the coil's + terminal to pin 24, and why?

Sorry, negative side and never positive...

Ok, but no 280ZX write up has pin 24 wired to the coil negative either. Did you change this recently, or what?

Point taken, I will be more careful with proofreading my posts.

The tach input is at pin 24 and the -coil is at pin 36. Always has been.