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Re: msd 7531 with nitrous

Posted: Tue Nov 10, 2015 10:29 am
by John_Heard
Two blinks is the error code for no cam sync. Which if you don't have the cam sync sensor is normal.

Hard to say what might be wrong, could be your crank trigger, or a coil, maybe the box is bad ? You have any spares to swap out?

Re: msd 7531 with nitrous

Posted: Tue Nov 10, 2015 11:01 am
by raffaplymouth
John. . when the car was OK. .. The led flash with trigger when pulsating when you crank. ... now make two flash. .. And no flash when cranking , coil is OK

Re: msd 7531 with nitrous

Posted: Tue Nov 10, 2015 11:25 am
by John_Heard
What do you use to trigger the MSD? A crank trigger? Distributor pickup? This article might help trouble shoot it -

http://www.dragstuff.com/techarticles/m ... oting.html

Re: msd 7531 with nitrous

Posted: Tue Nov 10, 2015 11:32 am
by raffaplymouth
crank trigger

Re: msd 7531 with nitrous

Posted: Tue Nov 10, 2015 11:40 am
by John_Heard
Those do act up from time to time. That article will show you how to test it. You can ohm it out, etc. to see what is wrong.

Re: msd 7531 with nitrous

Posted: Tue Nov 10, 2015 1:41 pm
by raffaplymouth
make test :
wrong flash ... I have not two flash but 3 flash ! 3 flash = low battery tension

trigger resistance is 80 ohm OK and trigger gap is correct .070

tension on msd connection when cranking is 10,6 volts ... is low ?? I have two battery on trunk and 100 ah alternator

Re: msd 7531 with nitrous

Posted: Tue Nov 10, 2015 2:40 pm
by John_Heard
I've seen them start with lower voltage, but all your signs are pointing at a low voltage situation. It sounds like testing your battery/s, battery connections, etc. would be worthwhile at this point.

Re: msd 7531 with nitrous

Posted: Thu Nov 12, 2015 5:45 am
by raffaplymouth
Checked everything is ok , now im speaking with MSD technical service ... i dont know what to do ... i have also checked the check spark with white wire at ground and green violet with jump .... no change ... no spark

Re: msd 7531 with nitrous

Posted: Thu Nov 12, 2015 7:26 am
by John_Heard
Starting to sound like you have a bad 7531 box.

Re: msd 7531 with nitrous

Posted: Thu Nov 12, 2015 7:40 am
by raffaplymouth
Yes John ...

Re: msd 7531 with nitrous

Posted: Wed Mar 30, 2016 1:47 pm
by raffaplymouth
hello .. Finally my box was damaged from tension jump ... now is repaired OK. . now this is the installation specs :

Idle 28 degree
total timing 36 degree
start retard 9 degree
nitrous activation retard 10 degree ( 250 HP) on pink wire

I don't understand very well the slew rate gear ... I don't want use this .. I fear that can active in automatic and make some problems.