Buggy Boyz
Former member ·
Is it only doing it when cold ? You mention it is only the first few corners ?
Confussed
Che Castro ankle straps
1,945 posts · joined Aug 2002 ·
flat spots are usually caused by too lean a mixture and/or insufficient advance, since she says it only happens for the first few corners i am guessing it is a fuel related problem.
First thing i would check is to see if the choke is working properly, it would probably cause those symptoms if the choke was disabled as when the engine is cold the fuel/air mixture doesnt vapourise as well and the fuel clings to the walls of the manifold and a lean mixture gets to the engine.
another thing that might agitate the above is not having the "stovepipe" setup (although this probably wouldnt be an issue now in summer). the stovepipe is the part that feeds warm air from either the heater box or cylinders to the air cleaner, this helps to prevent carb icing which would also give the above symptoms, although this is usually more a problem in cold climates.
other than that i can't really think of anything else without any more information.
is there a problem with stalling as well?
First thing i would check is to see if the choke is working properly, it would probably cause those symptoms if the choke was disabled as when the engine is cold the fuel/air mixture doesnt vapourise as well and the fuel clings to the walls of the manifold and a lean mixture gets to the engine.
another thing that might agitate the above is not having the "stovepipe" setup (although this probably wouldnt be an issue now in summer). the stovepipe is the part that feeds warm air from either the heater box or cylinders to the air cleaner, this helps to prevent carb icing which would also give the above symptoms, although this is usually more a problem in cold climates.
other than that i can't really think of anything else without any more information.
is there a problem with stalling as well?
Jon
aussiebug Officially Full-On Dubber
246 posts · joined Sep 2002 ·
Hmmm,
Incorrect choke is a possibility.
Vacuum canister not working? The vacuum port is on the LEFT of the carby - the other one is used in the US for double vac distributors - not here in Aus on single vac units. Sucking on the vacuum line should move the points plate and it should stay "pulled" if you cover the tube with your tongue - could the vac diaphragm be holed? The result would be inconsistent advance when you need it.
Inoperative heat riser (stove pipe). This does two things - stops icing under the carburettor, and keeps the fuel in suspension as it travels along the long induction manifold. Without it, the fuel tend to pool in the manifold and cause uneven mixtures. The manifold is supposed to be warm to touch all along it's length.
Jetting in the carburettor? With a vacuum distributor, you should have a 55 idle jet, 127.5 main jet and 60 air correction jet.
Air leak in the carby? - usually at the throttle shaft. With the engine idling, squirt some WD40 or similar at it (use the little straw to get real close) - if the rpm increase for a moment you have an air leak, which makes the car run lean, especailly at lower rpm, and that can sure cause hesitation.
What does "fully advanced" timing (point 2 in your first post) mean? - the correct timing for a vacuum equiped 1600 is 7.5BTDC.
Incorrect choke is a possibility.
Vacuum canister not working? The vacuum port is on the LEFT of the carby - the other one is used in the US for double vac distributors - not here in Aus on single vac units. Sucking on the vacuum line should move the points plate and it should stay "pulled" if you cover the tube with your tongue - could the vac diaphragm be holed? The result would be inconsistent advance when you need it.
Inoperative heat riser (stove pipe). This does two things - stops icing under the carburettor, and keeps the fuel in suspension as it travels along the long induction manifold. Without it, the fuel tend to pool in the manifold and cause uneven mixtures. The manifold is supposed to be warm to touch all along it's length.
Jetting in the carburettor? With a vacuum distributor, you should have a 55 idle jet, 127.5 main jet and 60 air correction jet.
Air leak in the carby? - usually at the throttle shaft. With the engine idling, squirt some WD40 or similar at it (use the little straw to get real close) - if the rpm increase for a moment you have an air leak, which makes the car run lean, especailly at lower rpm, and that can sure cause hesitation.
What does "fully advanced" timing (point 2 in your first post) mean? - the correct timing for a vacuum equiped 1600 is 7.5BTDC.
Rob
Rob and Dave's aircooled VW pages
Repairs and maintenance for the home mechanic
http://www.vw-resource.com
Rob and Dave's aircooled VW pages
Repairs and maintenance for the home mechanic
http://www.vw-resource.com
Bizarre Moderator The artist formerly known as blue74l
12,789 posts · joined Aug 2002 ·
3. Fitted brand new carby.
like do you mean a new 2nd hand or new-new?
Just sounds lean to me. When i was jetting up the Progressive they were the affects when i was too lean.
Air leak?
How about manifold boots? Cracked?
like do you mean a new 2nd hand or new-new?
Just sounds lean to me. When i was jetting up the Progressive they were the affects when i was too lean.
Air leak?
How about manifold boots? Cracked?
Futue te ipsum!!!
11CAB If ya got it....Baja it
4,674 posts · joined Aug 2002 ·
This may sound stupid, but since it is an acceleration problem, is the accelerator jet adjusted correctly?. It should squirt the instant you crack the throttle, if not there is an adjustment on the right hand side near the ALT/Generator.
65 Meyers Manx
68 Country Buggy (KO 367)
68 Country Buggy (KO 669)
68 Country Buggy (KO 789)
68 Country Buggy (KO 815)
68 Baja Bug
76 Baja Kombi Twincab
68 Country Buggy (KO 367)
68 Country Buggy (KO 669)
68 Country Buggy (KO 789)
68 Country Buggy (KO 815)
68 Baja Bug
76 Baja Kombi Twincab
70AutoStik Insano Dub Head
730 posts · joined Aug 2002 ·
The fault descritpion sounds just like a 009 - so checking the vacuum advance is a real good idea. The later comment prompts me to wonder if it's just a case of too much static advance - what worked on a fresh engine won't necessarily work once it's done a few miles. Try stock static advance setting and see if you still observe the problem. If you think timing is a rough thing, buy a Mallory with kit and try to maximise your performance - or drink a lot of cheap red wine every night - it will give you a similar headache.