what's wrong?!

My 73 beetle 1600 dual port has not been tuning up very well lately. It has a centrifigul advance distributor, but is otherwise stock. There is a hesitation on acceleration that lasts for quite awhile, and the real power doesn't seem to kick in until I've been holding a certain speed for a few seconds. So the acceleration...well...it sucks. These are the things I've done so far. This weekend I,

-adjusted the valves

-replaced rotor, cap, points.

-replaced air filter

-cleaned carb

-made sure accel. pump is functioning, it is, and the spray is directed on the throttle plate.

-set points gap

-set timing

-compression is fine I have not checked the spark plugs. I forgot to do that while they were out for the compression check, but they looked ok, not too black, and not burned up. I didn't check the gap or look to see if the electrodes are worn. Could this be the cause of all my problems?! Should I just install new spark plugs to see?

In additon, I've been timing my engine to 10 deg. BTDC. Several folks told me to set it at 7.5, but the local respected VW garage said 10 because of the altitude.(7000 ft) Does this seem correct for a mechanical distrib? My concern is that the dipstick is often to hot to hold when I arrive at my destination. It was at 7.5, and it is at

10 as well. Thanks for any help.

-Anthony

Reply to
Anthony
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Altitude, hesitates, and hot...

I'd guess (and by no means am I an authorized mechanic) that your running lean on the carb. I'd suggest replacing the mechanical fuel pump with an electric rotary vane type for 5.5 psi

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mounted in thefront, then up the main jet a couple of sizes. When you downshift does itbackfire? If so, you are running lean. I had problems with bogging coming and going and the electric pump solved the stability. I didn't bother rejetting the solex -- I moved to a weber progressive instead. Don't forget the block-off plate to fill the empty space when you take off the mechanical.

Reply to
David Gravereaux

Have you checked that your vacuum advance is actually working?

Grab the dist rotor and twist it clockwise. It should rotate (against some spring pressure, but smoothly) about 15 degrees and then snap back as soon as you release it.

There is a felt bad in the top of the dist shaft that needs some oil occasionally. Just a drop to keep this working freely and not rusted solid.

-

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Reply to
Jim Adney

He he he...the vacuum holes are plugged in the carb if that's what you're reffering to. Also, there are PLENTY of other beetles with stock 1600's using 009's that run just fine. Or am I missing your point?!

Reply to
Anthony

He he he...the vacuum holes are plugged in the carb if that's what you're reffering to. Also, there are PLENTY of other beetles with stock 1600's using 009's that run just fine. Or am I missing your point?!

Reply to
Anthony

Hiya Anthony,

Nope, I'm not referring to the vacuum ports on the carb.

But I think you're getting my point.

Seems to me that a team of automotive engineers designed a distributor specific to that particular application. Running that distributor will maximize total performance of that engine. Slipping in another distributor (designed for a different application) may increase performance in certain areas of the powerband, but will result in deficits in other areas. Note the stumble upon acceleration.

You mention that there are PLENTY (your caps, not mine) of other Beetles with stock 1600's using 009's that run just fine. Just two points for you to mull over.

  1. How come one of the most often heard complaints concerning Beetle performance is, "my 009, 34PICT3 equipped 1600 dp is suffering from a stumble on acceleration." There have volumes written on this very subject with many of these authors concluding that the 009 is a good dizzy if you have racing in mind. But it leaves a lot to be desired in terms of daily driving.

  1. Assuming that you use your Beetle as a daily driver, you know, stop and go driving, to and from work, running errands, and some pleasure driving on the side; perhaps your overall driving experience would be improved if you tried running the stock dizzy on your ride. "other Beetles with stock 1600's using

009's run just fine (sic)" Perhaps you will find that yours runs even better with a stock diz.
Reply to
Bookwus1

Anthony, Im having the same issues. The key point you made was "lately". I assume it ran well before? My engine ran well before last summer. It took a while to get warm in the winter and I could understand the hesitation that my .009/webber-dfev may have with the cold fla winters(45-50 f is cold for us) with no heat exchangers, but lately my engine is running crappy, hesitates on takeoff and does backfire on downshift kinda reminds me of an old harley after they rev up not a crisp shotgun souding backfire. I have checked and double checked for any intake leaks.. So i've been wondering if my crappy .009 was going bad (It seems to retard about 24 degrees and I set it at 30 @ 3000+ rpms). I think its interesting that the backfiring during downshifting is attributed to a lean condition because I was assuming that my carb might be bad, bowl overfilling due to worn needle valve and flooding. But I have heard that the solution to the hesitation of .009 was to richen up the mixture and that tends to go along with the backfiring issue. So maybe our problem or at least mine is a dirty carb or jet that would get worse with time or maybe just a mix adjustment.

I would like to get rid of the .009 but what dist works well with webber dfev or do I need to replace both?

Reply to
Bassbass99

Maybe check the springs in the 009 ? or maybe, borrow someone elses just for an hour or two ?

James

Reply to
Juper Wort

It is normal to see carbon deposits on the plugs, even if the engine is running lean, if the engine has been let to idle for sometime before or if it is mainly driven in trafic. The plugs can tell you if you are running rich when the engine has run in full or almost full load for some time, not at the low rpm range or while accelerating.

Most of the times, it is the carb that needs a thorough cleaning and readjusting (I have to clean my carb at least once or twice per year, but I drive my car a lot). Adjusting correctly the idle circuit is crucial for off-idle performance. The next most possible thing is that the manifold boots are leaking, it doesn't matter if they are new. Also check if you have a vacum port on the intake manifold (bellow the carb or to the sides of the aluminum castings), it must be well plugged. I don't think that the problem is distributor related (well, a small amount of the flat spot is related to the distributor, because the 009 with the

34PICT carb is not a very good combination). Even if a spring is broken inside the distributor, you would get a constant advance at all rpm, but you wouldn't get a flat spot at low rpm, instead the engine wouldn't pull at higher rpm (assuming that full advance is set to 10 degrees) and would overheat severely. It's even more rare to be something with the wires or the rotor (the High Voltage wires last many years, the rotor lasts many more).

Bill, '67 bug.

Reply to
Bill Spiliotopoulos

Hmmmmmmmm...this is good advice. Thank you. I don't really have any experience working on carbs, esp. taking them apart and putting them back together. I've decided to take the car to the shop and have them investigate the problem. They don't need to run a whole tune-up, but I'll have them set the timing and adjust the carb/idle/mixture/etc. BTW this is a very respectable ACVW shop, and they know these cars very well. Their initial valve adjustments, which have been checked by me three times now, have held for 6500 miles until no. 4 exhaust came a little loose. I'll keep you all updated! ~Anthony

Reply to
Anthony

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