MS2 V3 constant spark cut

Discussion pertaining to positive pressure E28s.
Post Reply
jrcanes55
Posts: 212
Joined: Jul 01, 2012 1:08 PM
Location: United States

MS2 V3 constant spark cut

Post by jrcanes55 »

Hey guys, so I completed my MS2 V3 board today and I have readings from every sensor, while cranking I am getting fuel, but no spark. Tuner studio shows spark cut when the car cranks. Does anyone know what could be causing that? I've been trying to figure out what the problem could be but I haven't been able to come up with anything. Car is running coil to distributor, B35 VR wheel and 21.5# injectors. Thanks!
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: MS2 V3 constant spark cut

Post by marc79euro645 »

Is your first led flickering as you crank? Indicating vr pulse
Is your rev limiter set too low on spark cut?
good luck
marc
jrcanes55
Posts: 212
Joined: Jul 01, 2012 1:08 PM
Location: United States

Re: MS2 V3 constant spark cut

Post by jrcanes55 »

Switched over to fuel cut and it started.
//grecko//
Posts: 64
Joined: Oct 12, 2012 5:22 PM
Location: Québec, Canada

Re: MS2 V3 constant spark cut

Post by //grecko// »

Had the same problem with a v3.57 assembly but I had no transistor in the q16 slot! :oops: Now I loses sync each second and can't pass 1200rpm. Will try with a 10k resistor on my VR signal!
jrcanes55
Posts: 212
Joined: Jul 01, 2012 1:08 PM
Location: United States

Re: MS2 V3 constant spark cut

Post by jrcanes55 »

Well now I've got the ignition working but the car is almost constantly dropping tach signal, I need to re do the crank sensor wire as I did not use shielded wire (duhh) anyone know any common places to get it? All i've found so far are rolls of 150+ feet online. I'm also debating re using the wire from the two old crank sensor that are no longer being used.

As of now, turning the car over, the tach reads perfectly. As soon as it starts it starts dropping signal and spazzing out. Sound like a noise issue to anyone else?
turbodan
Posts: 9223
Joined: Jan 09, 2007 10:19 PM

Re: MS2 V3 constant spark cut

Post by turbodan »

Definitely fix the obvious issue and go from there. The VR sensor signal wiring must be shielded.
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: MS2 V3 constant spark cut

Post by marc79euro645 »

I had to tune my pots (R56 and r52) to get a solid vr pulse.
http://www.megamanual.com/ms2/vradjust.htm
marc
//grecko//
Posts: 64
Joined: Oct 12, 2012 5:22 PM
Location: Québec, Canada

Re: MS2 V3 constant spark cut

Post by //grecko// »

Try to put a 5 to 10k resistor inline to your + signal...
jrcanes55
Posts: 212
Joined: Jul 01, 2012 1:08 PM
Location: United States

Re: MS2 V3 constant spark cut

Post by jrcanes55 »

Video of the car running. I'm going to add the resistor and get shielded wire.

http://youtu.be/FGSFB0q4LB8
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: MS2 V3 constant spark cut

Post by marc79euro645 »

Your rpm looks low, I think your missing vr pulses even though it's running. Better tune those pots
Glad to see it's running!
marc
jrcanes55
Posts: 212
Joined: Jul 01, 2012 1:08 PM
Location: United States

Re: MS2 V3 constant spark cut

Post by jrcanes55 »

Im having grounding issues with the ms unit, If you watch the video all of the sensors will drop, not just tach input, i've been trying to hunt down the problem with no luck.

With the ignition on before start, all sensors read as they should, as soon as the car starts everything start to flip out, I'm lost at this point, not really sure where to look next, I've changed a few grounds and have had no luck.
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: MS2 V3 constant spark cut

Post by marc79euro645 »

Have you tried tuning the pots?
Post Reply