MSD 6AL Ignition Module and Ignition Wires

[911S 2.7]

Hi!

Just removed the bosh ignition and installed a MSD 6AL with MSD Blaster Coil. The cars starts great, but not runs well... my car has become a kenguru... Is there a must to change the orginal ignition wire as well? Change to Magnecor KV85 Competition (8.5mm) Ignition Cables - will this help me to have a smoother ride?

Thanks!

Joachim Myhre

[GrantG]

Sounds like a problem with the 6AL wiring. The Blaster coil works fine with regular Porsche (Beru) wires. I upgraded to Magnecor when the originals wore out - not much difference. You might want to check that the installation of the MSD unit is correct...

[911S 2.7]

ok, thanks!

[Early_S_Man]

Joachim,

Is that a High-Vibration epoxy-filled coil? The oil-filled, metal-cased coils that are also called 'Blaster' are NOT supposed to be tilted downwards like the stoick 911 coil is ...

Another thing to check is the end-to-end resistance of the stock Beru spark plug wires. All should be 3 - 4000 Ohms. If one or more of the Beru connectors have failed 'open' ... it can result in a miss that causes the engine to shake badly.

[911S 2.7]

Yes, partnumber MSD-PN8222

What do you mean by failed "open"? If thats the problem, do I need to buy some new wires?

[GrantG]

If a wire fails "open", it's resistance will be too high to measure (infinite). You can check with multimeter set to "ohms".

[Early_S_Man]

The ends of the OEM Beru wire set unscrew from the black copper-cored wire.

The Beru connector at the spark plug has a built-in resistor of nominal 3000 Ohm resistance. That resistance element can fracture and go 'open' so there is no continuity from the wire end to the spark plug end. They can also be intermittent, so that is why I have recommended a 'shake' test where the ends and held tightly to test leads and the connector is shaken strongly.

The distributor end of the wire may or may not have a 1000 Ohm resistance element. Same tests as above.

Replacement screw-on ends are available.

The wire/cable portion can be replaced with bulk cable from many sources.

ps,

The miss you describe may be caused by arcing of the wires to grounded sheet metal or engine parts due to cracks and pinholes in the insulation ... before it gets to the spark plug. Look for arcing or a blue 'corona effect' around portions of the wires with the engine running in a dark garage or on a moonless night. If you see a light 'show,' the wire portion needs to be replaced!

[Paulporsche]

After about 16 years of using OE wires, I switched to the MSD wires when I went to the MSD CD box and Blaster coil, which was about a year and a half ago. The combination works great.

[RoninLB]

some pelicanheads reported rpm limiting distributor rotors became damaged with MSD CD box.

I now use pelican parts non-rpm-limiting rotor

part number Bos-04038