My A12 (in my 1000) has been doing these tricks for a while now...

(1) When i start it from cold it back/forward-fires out the carbie (no air filter) and...

(2) After i stop (ignition off), it seems to keep firing but if I let the clutch out its actually going backwards???

This is a highly abused engine/car so anything is possible.

Bizarre man..I can't explain that...Unless you've been eating them mushrooms again..

Chris

Probably the "Coriolis Effect." You know, the force that makes the toilet water spin the opposite direction in the southern and northern hemispheres.

But seriously, I have had that same thing happen, the apparent spinning backwards after shutting off. I never did finger that one out! I just let out the clutch as I shut off the key. Got to the point where you couldn't even tell I was doing it.

You've actually watched it spin bacwards or you just think that what it feels like from the drivers seat? If so it's probably just red hot carbon deposits in your engine keeping it running in the normal rotation. Sounds like you have a timing problem.

re: "red hot carbon deposits" isn't that called Dieseling?

re: Spinning backwards... when I stop it can chug along for about 15-20 seconds sometimes and if I let the clutch out with no brakes on it'll launch backwards in first.

re: Timing... Thats what I thought, but after a professional mechanic tuned it it still does it.

Ah, well, as long as nothing is gunna die because of it.

thats right, datsuns never die!

Dieseling is mainly caused by too fast an idle. The newer cars (after 1972 or so) had faster idles, leaner carbs, etc that made this type of problem somewhat common. That's why the newer carbs have the anti-dieseling solenoid.

Set the idle down to 600 rpm (with engine hot), and I bet the problem disappears.

If not, you may have an air leak (not vacuum, but air), like loose/worn throttle shafts. Also, watch the idle linkage and dashpot, you might set it, but later it's idling fast again.

And put an air filter on that engine!

They have anti-dieseling soleniods on 73 1200's too. If that thing doesn't work, your car will not idle after it warms up (choke opens, idle circuit in use).
Anyways, you could probably give the idle mixture screw a 1/4-1/2 turn out so it doesn't idle so lean. I've heard that dieseling usually means a messed up idle mixture.
good luck