background: Friday morning i drove the 911 to work; ran fine. Friday
night wouldn't start - no spark. looked (in the fading light) like
bad points - worn or broken rubbing block. had a spare set of points,
took a couple of days to find 'em. meanwhile ordered the Crane points
replacement module which, through a series of issues, should be here
Tuesday. got back to the car today, replaced the points. no spark.
checked the gap, all that, verified open/close with a meter. no spark.
verified all connections to the MSD box; fine. tested the 'coil' and
it appears just fine - and anyway - tach output from the MSD box is
independent of the coil.

looks like YET ANOTHER sudden MSD-6 failure. i like these when they
work but i'm afraid they're just too fragile for the real world...

so my options are (as i see them right now) to get YET ANOTHER MSD-6AL
overnighted here, or cancel/return the Crane 700 points replacement
module and instead get the Crane/Allison 735 or the X3000 equivalent
(full CD ignition) with the points replacement optical shutter and a built-in CD box.

am i the only one to be having problems with MSD boxes ? (i bought
this one used, might have had a prior 'issue' but was "tested OK' by
AutoTronic (surprise!) anyway - i got my money's worth to this point
but now we're working on what to do next ...) does the performance
advantage (over the Crane) outweigh their fragility ? is the Crane
fragile too? is MSD's reputation justified ? i notice every NASCAR
cup car uses them, but every NASCAR cup car uses TWO, so the failure
of one won't leave them out of the points. Autotronic doesn't sponsor
me, and i ain't runnin' two boxes on a single-plug car just so i won't
get stranded...

open to suggestions here, i want to pull the trigger on whatever i do
ASAP ...

either way (MSD or Crane) i will be using the Crane points replacement module.
i'm using an aftermarket (AutoMeter) tach so operation with the stock tach is not required but this one is ...

How many CD boxes have you been through on the car?

Rich,

What about the Nascar or Heavy Duty off road version of the box, it's supposed to have better shock absorption capabilities.

I have the Crane CD and optical points are have had no problems.

Paul

Rich:
Did you test the MSD?

There is a proceedure for testing it.
(edit)
oh, I know the proceedure.

well - it came with zero, i put in one, and it looks like it's dead so - one.

even the NASCAR guys feel they have to run two :-) ...

this is a frikken' street car... how much shock absorbtion should it need!? it's mounted on the MSD-supplied vibration-isolation mounts, on the vertical portion of the firewall where "everybody" mounts them. no more MSD for me - i'm goin' Crane ...

that's the way i'm headed. Crane 700-series points replacement module, triggering a '6000-6440' "Fireball HI-6" multi-spark, rev-limiting spark box. it's the one the Crane web page shows as a direct replacement for the MSD-6AL. i'll give it a whirl ...

6 ways from Sunday...

got switched power, got unswitched (main) power. got ground. got pulse train on the trigger (points) wire. got no tach output, got no spark.

repeatedly grounded the white wire, which the manual says will "always" cause spark. doesn't. verified the green and purple wires (mag trigger) are not shorting to anything - that's another way tp shut down the box. it's fine.

it's all outta there. i think i'll have AAA tow the car home so i don't have to deal with it in the "company parking lot" - the boss' back yard.

In Other News - i'm pretty sure the new oil leak is the leftside cam oil line - got one of those and the connection bits coming. new dizzy O-ring coming. new Bosch cap & 911S 73-- rev-limit rotor coming. i wanna be DONE with this !

I wasn't sharpshooting or giving you an attitude.

I didn't know if your past problems with the MSD were all in this car.

-Rusty

i didn't take it that way at all, so no problem.

but i am 0 for 2 with MSD so it's time for something new. i'm liking what i'm reading about the HI-6. we'll see what the reality is once i get it into the car. got some very nice features tho..

i've got parts coming in from all over, what with the holiday i have no idea what that'll do to delivery schedules. i'm thinking i'll get the car towed back home tonight and start ripping out the MSD stuff and doing some of the other stuff i can do without the car running (like, brakelines...) i can pull the dizzy and get it ready for the XR-700. i can think about pulling the muffler and pulling the tinwork so i can do the chain tensioners ...

then put it all back together when the parts come in ...

It won't provide a spark if the coil is bad....or the connections to the coil are bad....BTDT.

yup, that's true. i did the connections myself with 14Ga wire in what - June ? i always use ring terminals - never quick-connect spade-type terminals. measured voltage ON the coil pins.

also - the MSD will still provide a tach output even if there is no coil. i got no tach output. the first dead one did that too,