Darn those sticky blades

Post date: Sep 10, 2012 4:13:08 AM

tl;dr: Bloody stupid secondary blades were sticking (very very slightly) open and causing much hilarity.

I've been chasing my tail on a wide variety of ignition and carb problems, basically with the result of the car running very poorly. The main thing I saw was intermittent spark, usually on #7, #5, maybe one or two on the right bank, when running the new dizzy. Yet it seemed to run pretty well with the old dizzy and coil, right?

So I left in the old and started working on the carb. The air bleeds are now down at 0.070", idles at 1,000 in neutral and 700 in gear, pulls 14" vac. Still more to gain. Total timing advance is about 36deg@idle with the vacuum on manifold. Might still need some more.

On a lark, I put in the new dizzy and old coil, and it seemed to run really well. What the heck, right? So I figure, ah-ha!, must be the new coil!

Meanwhile, the brake master took a complete dump. So I haul down to the Forest OReilly to get a new master, and get a MSD Blaster 2 coil figuring the ubiquitous coil would be a good step up from the who-knows-what that I have now.

Put in the coil, it fires up and is running pretty good. Go out for a spin, and after a few minutes, it suddenly is idling terribly, bucking like a bronco, just all messed up. Come home, yell some cuss words, put in the old dizzy, it's running fine!

Go out for another drive, then it starts messing up again! The O2 sensor swings dramatically rich. I pull over to see if it's dumping gas straight in the intake, and note a whole lot of smoke out the tail pipes. Appears white. Get it home, and it's smoking like crazy, starts looking blue.

I'm thinking the worst at this point.

Pull the plugs, and they are *black* with carbon, not oil. Take a look at the carb, tap the secondaries, and they close.

Hm.

Get some new plugs, unhook the secondaries, and it's running great!

Swap back in the new dizzy, it's running great!

Just shoot me.

My only guess is the new dizzy is more sensitive to fouled plugs, and the new coil makes it even more so. Who knows why. Seems like a hotter spark would be less vulnerable, but there it is. It has the blaster 2 in right now, I'll switch back to the FlameThrower HC and see what happens. At least switching coils is much faster than switching distributors.

Fun note: the 403 running on two barrels is about as fast as my Lincoln LS. This car will be a lot of fun.

I moved down two steps in main jets, so it's 71 and 50B rods now. Still *very* rich, cruising around 12:1. Total ignition timing is 36deg, base at 24deg, vacuum pulls in another 12 or so. I put my fancy APT a turn or two richer than stock, so probably time to start bringing that down. All the tuning guides say to start with rods and jets about 30thou difference. Clearly that just doesn't work with Olds.

In other news, the quad gauge had to go back to New Vintage again. Their quick fix for the needles hitting the standoffs didn't work too well. While I was at it, I did a test wire of the speedo, hooked the sender up to a drill and took a "spin".

Chuckle chuckle.

I really want to have the 255k miles on the clock, so I wired up a quick 555 circuit to feed a square wave to the gauge. It runs about 100 miles per minute which appears to be as fast as the gauge can latch on the signal. At that rate, it's roughly 48 hours to 255k. Not bad to catch up on 41 years!