irobertson

I chased a similar issue for months. Tried everything. In the end it turned out to be a bad DME. I got a refurbished one from Steve Wong and have had no issues since.

NineMeister

That's a relay for cars equipped with a catalytic converter, not fitted to ROW cars from what I can see.
On an SC the rev limiter is the spring plunger device in the rotor arm, shorts out the spark at the prescribed RPM (as written on the rotor).

OP's fault is likely to be electrical, so sift through the obvious first. Check the fuel pump fuse, the fuse terminals and the fuel pump relay & terminals first, then work through ground points and other electrical connections before substituting (expensive) parts.

Mark Salvetti

Colin,

I didn't realize the ROW SC's didn't have cats and used mechanical rev limiters. But since Edward is in SoCal, unless he has a conversion, he'll have this relay (plus he found it).

Easy to disable, so worth the shot. I agree it is unlikely though. These things don't seem to go bad often. Just search Rennlist and Pelican - you won't find much about this relay.

Not likely the DME - SC's don't have one.

Curiously waiting for Edward to update us.

Mark

Lorenfb

The thread is about a 911SC and NOT a 911 3.2. You are aware that a 911SC does NOT have
a DME ECM nor a DME relay, right?

Edward

Hey Mark. Timely post: I came here literally just now to post an update

So to clarify, my 82 SC is stock US, all running gear is stock except for SSI and Dansk sport 2:1 muff. CIS is bone stock and before this intermittent snafu all ran great, loves to rev and pulls strong in all gears, thankfully! So here's the update: pulled the molex on said rev limiter and zero problems!!!

This is not my DD (it's a "Trackmeister" that I run on the street nearly every week to keep it exercised), but have commuted with it for 3 straight days now, and not one hiccup!!!. Given it "cut/stuttered" 3-4x every time I drove it those two days, I'd say the rev limiter is officially the culprit.

Big, mondo thanks to you Mark! I would have otherwise gone the normal troubleshooting route of rooting through the electrical, then fuel, none of which would have been cheap. You saved me buckets of time, frustration, and clearly dough. I owe you, friend! Any time you're in my hood, the brew is on me, man!
And in the words of the esteemed cogniciencti here, "is this place great, or what?"

Edward

Mark Salvetti

That's fantastic! Thanks so much for the kind words, glad I was able to help!

Mark