Hello, i'm new to this forum and i'm hoping to get some information into this system.

i've installed a MSD 6AL into this car but i cannot get it to fire. MSD thinks it might not be compatible to this vehicle

It seems that my issue relies on the - COIL wire coming from the DME " - coil output control" I tested the MSD box as instructed in the installation manual and it does work.

The box was sent back to MSD and they said it was defective, the 2nd time the vehicle still doesn't fire.

Vehicle starts no problem when original ignition is put back.

Has anyone installed such set up and if YES what am i doing wrong? Thanks for reading

 

can only be 1 of 2 things. It's hooked up wrong or the MSD is bad, which they are known to do. I wired mine to be easily changed back to stock by swapping the plug

 

Thanks for the input GPR8ER, It seems you have the 6A and i'm using the 6AL Part #6425, I sent the box back to MSD 2 weeks ago and they found it to be defective and i this weekend i tried it again with no luck.

I can test the box by grounding the white wire to the block and having a Spark tester in line to the coil wire and i can see spark flowing.

Do you happen to have thaat plug part number?

 

I did the same as GPR8ER. That's a WeatherPac one-wire connector, widely available (Pepboys, Summit, etc.). As for you 6AL, I have to imagine it's not wired or configured right? I'll see if I can dig up my 6A wiring, but recall you need to make sure it's configured for a 4 cylinder and, in your case, set the rev limits. Maybe post up your wiring in the meantime. If MSD confirmed the first one was bad, and now this one isn't working, you have to wonder if you are zapping it somehow by the way you are hooking it up... Why did you want the 6AL by the way? Seems unlikely it isn't compatible since the 6A works fine, but if that turns out to be the case, the 6A works great on these cars (and it's cheap)!

 

See wiring here.
https://rennlist.com/forums/944-turb...g-msd-6al.html

And see here about someone who ran the 6AL on his car. Absent amazingly bad luck with two bad units, my guess is you have the polarity wrong on the factory coil wires (black is positive, go figure) or didn't set it to 4 cylinder mode....
https://rennlist.com/forums/924-931-...-mounting.html

Keep at it, it's a worthy upgrade.

edit: don't forget you also need the right spark plug wires and coil...

 

Hello tom, here's how i'm installing this set up.


You are correct, the "Black" wire is Positive(+ SIDE of coil) 12 V from the ignition switch and "Green wire" is output control (- SIDE of coil) from DME at PIN # 1.

I did cut the two loops to configure the MSD for a 4 CYL application and still can't get it to fire.
I've been working on cars for 10 years professionally and i don't think i'm doing anything wrong but anything is possible.

I might have a defective UNIT

 

So to confirm, you have 6 wires (on only 6) connected:

MSD small red to Porsche harness positive coil wire (black)
MSD small white to Porsche harness negative coil wire (green with stripe)
MSD thick red to battery positive
MSD thick black to battery negative
MSD Orange to MSD coil positive
MSD small black to MSD coil negative

Rev limits set to max, loops cut for 4 cylinder mode, and spiral wound spark plug wires? If all that checks out, then you might ohm out the MSD harness to make sure all signals are getting to the box, especially if you reused wiring from the original defective unit.

 

All of that is correct. I installed a new harness for round 2 as well. Spark plug wires were ordered from Lindsey racing http://www.lindseyracing.com/LR/Pors...GWIRE-944.html

Thanks for posting

 

Are you sure those LR wires are MSD compatible? MSD makes a big deal out of insisting on spiral wound or suppression wires, like Magnecor.

 

I'm not sure if the wires are the right spec for the MSD set up, but if they aren't i will recommend the proper wires once this is resolve when testing the MSD box(Tapping the white wire rapidly at ground) with a Spark tester in line with the coil wire i can see a nice spark flow/nasty@ 35 KB when cranking there's not spark at all.

I spoke with MSD, they are willing to take the box and exchange with a new one.

I want to recommend the regular 6A instead of the 6AL and get the same set up as gpr8er

 

If you look at the link I posted above, it seems that others have not had problems with the 6AL. That said, I can personally attest to the 6A Box, with Magnecor wires, and an HVC-II MSD (8253) coil. When you say you plan to "recommend" things, does that mean you are working on someone else's car? Not sure I follow when you are seeing a flow/nasty spark and when you are not seeing a spark at all?

 

Yeah, It's a customer's car. He bought the parts and brought them to me to install.

What i was trying to say by nasty spark i meant that i am getting spark when i test the MSD by how MSD recommends testing it for spark.

I'll look into that link, thanks tom

 

Found this on the msd support site:

REV LIMITER VERIFICATION
The MSD Digital 6AL has a built in Rev Limiter Verification
feature. When the key is in the On position (not cranking or
running), an rpm signal is sent to the tachometer to verify
the unit's rev limit setting. With this function users can be
sure of their rev limit settings before each drive.
Disable with EFI: Users who are pairing the unit with an
EFI system may experience issues with this feature. If the
system's ECU detects high rpm shortly after the engine
starts it may prompt the injectors to supply fuel for a given RPM. Not all EFI systems will experience
this flooding problem. If a system has issues because of the Rev Limiter Verification feture, the feature
can be turned off with a simple process.
1. Ground the Gray tach output wire.
2. Turn on power to the ignition without starting the engine.
3. Hold the Gray tach output wire to ground for seven seconds.
a. (AT LEAST five seconds)
4. Release the wire from ground before ten seconds have passed.
5. To confirm the process has worked, cycle the ignition power off and back on. Watch to see if the
tach goes through the Rev Limiter Verification or not.
As soon as this process is complete the feature will be turned off. The Digital 6AL uses the red LED
to help indicate when an adequate amount of time has passed to release the Gray tach wire. The
LED will turn on after the wire has been grounded for five seconds and will turn off at the 10 second
mark. To activate the feature again, repeate the same process.

 

I also did that test along the Tach adapter 8910 with no avail.

I'm going to look into those plugs for the MSD that makes it very easy to switch back to stock...
I'm still waiting for a phone call from MSD