S30 MSD Street Fire FAILS

[Jazz86]

Hello good folks at hybridz. Time to share my bittersweet experience with my MSD street fire ignition. 

In one phrase: "Sweet, but not to last"

 

I bought the MSD ignition after all the things people were praising it for. I was sugared into the idea that my 240z needed a special spicy shocky sparky super smash MSD ignition. In all honesty for 3 months it worked wonderfully. However, after 3 months the MSD unit showed horrible signs of failure. 

1. Misfires from 1000-3000 rpm. When cruising around town, normal driving the engine will have a few farts and coughs.

2. High RPM MISFIRE, the engine would start to "break up" at any rpm over 4500rpm. The engine felt like it had an imposed rev limiter by not firing. NOT the MSD's rev limiter, that was working fine(easy test)

3. Odd idling, the engine would idle around 2000 rpm, then 600rpm then it would have problems starting .

 

 

3 months the unit started to fail... 8 months the unit stopped firing all together. MSD probably built this unit to fail right after the warranty. I had to rewire my ignition on the side of the road to fix it. Next thing I know my pooch of a 3.0 motor now is driving great. I had built this sweet 3.0 motor for road racing but what is the point if the engine could not rev past 5000rpm. THE DARN MSD was the weak link, and prevented me from using the power that was hidden past 5000rpms.  Now the engine revs to 8000rpm no problem. 

 

HIGH RPM MISFIRES CAUSED BY MSD IGNITION

[Zcardude]

That's interesting that you mention that. I have the same unit triggered by an MS2 and have some weird power delivery issues, where the torque drops off rapidly, then come right back, producing a really oddball (and sorta disappointing? It makes 258whp but should be able to do more) power curve. Did you have the opportunity to dyno yours with the problematic MSD StreetFire? I'm curious what it looked like on your setup. Posted mine below for reference

 

Some other members here have speculated that it is caused by noise coming in through the optical pickup on my L28ET distributor, but I originally was thinking it might be a problem with the MSD StreetFire unit. Now you've got me wondering... I've got an MSD 6AL box to try as well as a different trigger wheel for my distributor so I can basically eliminate either or both from my setup. Will definitely post back in this thread once I have more information.

 

 

[Jazz86]

On 9/15/2019 at 10:08 PM, Zcardude said:

That's interesting that you mention that. I have the same unit triggered by an MS2 and have some weird power delivery issues, where the torque drops off rapidly, then come right back, producing a really oddball (and sorta disappointing? It makes 258whp but should be able to do more) power curve. Did you have the opportunity to dyno yours with the problematic MSD StreetFire? I'm curious what it looked like on your setup. Posted mine below for reference

 

Some other members here have speculated that it is caused by noise coming in through the optical pickup on my L28ET distributor, but I originally was thinking it might be a problem with the MSD StreetFire unit. Now you've got me wondering... I've got an MSD 6AL box to try as well as a different trigger wheel for my distributor so I can basically eliminate either or both from my setup. Will definitely post back in this thread once I have more information.

 

 

 

 

Very interesting input. Sadly I have not dynoed my 3.0 motor. Very interesting, my misfire was around the exact same RPM range. This is definitely something to look into since you have a large torque drop at the same RPM. I am currently rebuilding my MSD unit with a few of my friends. 
 

I was told, that it might NOT be my failed MSD that was causing my misfire, rather an electronic noise issue or odd frequencies. Personally I would love to test the MSD box for high speed triggering and see if there is a drop off or maybe a timing delay in the system. If only I had access to my old college electrics class  equipment.

 

So far things I am planning to rule out and test

1. Bad capacitors in my MSD unit (currently dissecting) 

2. Electronic noise/interference  (solved with either capacitor or resistor or a high pass or low pass filter)

3. MSD timing delay, so maybe there is an input out put delay from the trigger and box (simple fix advance timing more/high risk of detonation) I do know that MSD had a special box that will delay the spark a little in the case of high boost or nitrous, and that box is meant to retard timing.