Too much advance in my timing?

[nycmagician]

Ok ... My equipment:

- '77 Bay bus with a '78 engine
- Weber 32/36 carbs
- 009 distributor
- PerTronix 1847A electronic ignitor
- PerTronix 40511 Flame-Thrower coil.

From reading on the forums 009 distributors are supposed to be timed to 28-32 degrees advanced at 3,000+ RPM. I have timed my bus that way and the idle falls to about 8 degrees advanced. It's running terribly. When I put my foot on the gas, it hesitates and stumbles and I get no power until the RPMs are much higher. It's not drivable in this condition, but does get slightly better (but by no means good) as the engine warms up.

I have advanced the timing a little and the bus is running much better. The idle falls at 14 degrees advanced and the maximum advance is around 38 degrees. She's still not great cold, but when she warms up, she runs OK. As I was adjusting the timing to make it more advanced, the idle speed increased and the engine sounded better than when it was set to 8 degrees.

I know engines run a little hotter with more advanced timing but am I doing damage running this higher advance timing? What can I do to make her run better with the 28-32 published timing?

Thanks in advance (PUN INTENDED)

Doug

[SGKent]

the fuel has problems turning to vapor in the cold unheated manifold and runners. This leaves the molecules of fuel poorly mixed with air, which requires longer to burn. By adding more advance you are giving it longer to burn - however at higher RPM's under load that could cause engine damage.

The real solution is to add a heated manifold and runners but no one that I know makes such an item. This is why so many people with progressive carbs on type 4 engines complain about the same problems, and gasp. A faster idle may help.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[nycmagician]

[Wildthings]

You can disassemble your distributor and bend the limiting stops for the centrifugal weights to limit the weights' movement. This will allow you to run more initial advance while the full centrifugal advance is still in the safe zone. So long as the engine will crank and start and doesn't knock at low speeds you are fine.

Take a gander at the Progressives Suck thread, it has a lot of useful info on these carbs.

http://www.thesamba.com/vw/forum/viewtopic.php?t=217070

[nycmagician]

[Tcash]

The initial setting should be
Timing Set At:: 7.5deg BTDC @ 850-950 rpm (Man Trans), 900-1000 rpm (Auto Trans) w/strobe, vacuum hose connected

It should idle fine at 8*. You have something else going on.

You need to start with a good tune up. Before you adjust the carb-carbs. Do you have a single or duel carbs?

Tune up

https://www.youtube.com/watch?v=A44-xG3pKlY
https://www.youtube.com/watch?v=fhYSo6u-Jm0
https://www.youtube.com/watch?v=BfIH26O2Ijg

Good luck
Tcash

[SGKent]

there is also a possibility your timing scale is off, or your light has an adjusting knob on it for changing the light timing, and that knob is not set on zero.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[mnskmobi]

When I ran a weber progressive, the biggest single improvement I made in the driveability was to fit an air cleaner from another car (can't remember the make/model) so that it would feed in warm air initially (controlled by a thermostat). Prior to that, I had times when the fuel dropout in the runners was so bad it was undriveable!

[nycmagician]

[nycmagician]

[Tcash]

Finding TDC on a Type IV engine cannot be done by locating off the top of the piston. The spark plug angle does not allow access to the top of the piston.

Finding TDC Type IV Engine

1. Take an old spark plug and grind the top chamfer from it.
2. Grind or cut the ground electrode off.
3. Use a punch and knock the porcelain out from the bottom.
4. Run a 3/8" NPT tap through the empty spark plug shell.
5. Thread a 3/8" barbed hose fitting with teflon into the shell.
6. Connect a length of clear plastic tubing to the fitting.
7. Remove all spark plugs.
8. Stick your thumb OVER the #1 cylinder spark plug hole. Rotate the engine until you feel pressure on your thumb. That's the compression stroke.
9. Screw in the spark plug with plastic tubing attached and insert the other end of the tube into a jar of light oil. Continue rotating the engine. Bubbles will appear until the piston reaches the top of its travel. When it starts down on the next stroke, the bubbles will stop and oil will begin traveling up the tube. Stop at a convenient point and mark the tube. Then mark the crank pulley and the engine body at a convenient spot.
10. Rotate the engine backwards and watch the oil recede into the jar. Continue rotating. As the piston continues past TDC and downward it will again suck oil into the tube. Rotate the engine till the oil again reaches the mark. STOP! Mark the crankshaft pulley where it lines up with the mark you made previously on the engine. You should now have two marks on the crankshaft pulley. The midpoint of these two marks lined up with the mark on the engine is TDC.

http://www.wikihow.com/Find-Your-Engines-Top-Dead-Center-TDC
https://ww2.gates.com/europe/file_display_common.c...5005%2Epdf