Help MSD street fire

[emac]

Need help- installed MSD street fire as listed below car started right up but backfires bad when I press gas.

Heavy Red to top block of three fuses in rear
Heavy Blk to ground
Red to center bottom of six pin
Orange to right bottom
Black to right top
Gray to center top
Violet to left bottom
Green to top left
White is taped off

Thanks in advance
Ernie 81 SC

[Dmitry at Pelican Parts]

Hi Ernie - I've attached a link to one of our site's DIYs on the MSD system. I hope this will help you troubleshoot.

Porsche 911/928/944 MSD Ignition System installation | 1965-1989 | Pelican Parts DIY Maitenance Article


-Dmitry

[timmy2]

Try swapping green and violet wires.
Did you check your timing?
What did you set your rev limiter to?

[emac]

Timmy
Timing is set to spec. did not touch it
Rev limiter is 6,200
I will try switching the wires
I did not regap the plugs yet. Set at .026

[Pazuzu]

I believe that the Streetfire matches the factory CDI when wiring the Green wire, while the 6AL is switched.

In other words, wire the green and violet wire the way they came from the factory, not the way all of the threads here tell you to wire them, since all of those threads are about wiring up a 6AL...

[emac]

Dennis
Switched the wires and all is good
Thank you for you help
Ernie

[Bob Kontak]

Originally Posted by emac

Timmy
Timing is set to spec. did not touch it
Rev limiter is 6,200
I will try switching the wires
I did not regap the plugs yet. Set at .026

Set at 0.029 factory. Easy to go to 0.035 with MSD. Secondary though.

If it backfires your O2 circuit fuse may be blown. It kills the frequency valve's function. It will idle but falter, stumble and pop when you give it gas. Mine is doing that now. Once you have experienced this a few times, you check the fuse, pull and re-install the Lambda box relay (little cube relay under passenger seat connected to Lambda unit). Fuse is third or fourth one towards front bumper from driver's position. Black cover will say OXY on it for the location.

[Bob Kontak]

Originally Posted by emac

Dennis
Switched the wires and all is good
Thank you for you help
Ernie

Sweet.

[Gretz]

Sorry to resurrect an old thread but I'm getting ready to install my Streetfire.

I was planning to run the power cable to the rear fuse panel, but I know I could also run it directly to the starter power connection. Any benefit to running it directly to the starter as opposed to the rear fuse panel? Obviously running it to the starter is a bigger pain in the butt.

[dicklague]

Originally Posted by Gretz

Sorry to resurrect an old thread but I'm getting ready to install my Streetfire.

I was planning to run the power cable to the rear fuse panel, but I know I could also run it directly to the starter power connection. Any benefit to running it directly to the starter as opposed to the rear fuse panel? Obviously running it to the starter is a bigger pain in the butt.

RUN IT TO THE STARTER! I like to put an electro capacitor in th circuit too.

[Gretz]

Someone I trust told me there’s really no benefit to running it to the starter. What’s your rationale?