I am having a problem with my stock standard 69 beetle daily driver. I will try to explain the symptoms. My car easily starts first go every time when cold, no problem there. I let it warm up untill engine temp increases and begins to run smooth, no problem there either. The problem starts after I have driven off, at very low revs no problem, as soon as I increase ecceration the car begins to"chug" ,but only as I increase revs. This continues untill I have managed to increase engine temperature further and after that I don't have a problem. In short the car wont run smoothly untill engine temperature has increased, way beyond what it normally should. This is only something that has developed recently, so I am at a loss as to what the problem is. Any help would be appreciated.
Hi
It should not necessary to warm your car up at all, you only need to drive carefully for a few ks. Maybe your choke is staying on and choking the motor, otherwise do full tune up and see how you go.
Steve
Thanks Steve,
Would that account for it running OK when the engine is at a higher temperature?
sdat wrote:Thanks Steve,
Would that account for it running OK when the engine is at a higher temperature?
No. OK hot bad cold indicates too lean, not choke stuck on.
Certainly lots to check tune up wise, valves, points, timing, spark plugs, and thats before you even start to fault find!
When was the last full service? Take a good photo of the engine, what distributer, carb combo?
What size engine?
Even non std air filter can cause tuning probs!
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
Last service was 2000 miles ago, it has been acting up before and since then. The timing was checked, but otherwise it was a minor service. The engine is a H series, but had top end rebuilt by previous owner around 2000 so no sure if it was upgraded from 1500 to 1600. The motor appears stock except for the bosch 009 mech advance distributer.
It would be worth checking your timing again. Some people set them at 0 degrees idle (vacumme dissy) and this wont work with a 009 dissy. It will need to be set at around 6 degrees at idle, checking the total advance stays under 32 degrees. Also if someone sets the timing too far advanced it will chug when cold but drive fine when hot. It would also explain the motor running hotter than usual.
And also check the carby out for fouling linkage or freshly moved parts ie. incase they have turned or bent an adjuster. Sometimes saves time. When you say to chugs have someone watch as you drive off to see if there's visable black smoke. If the choke was stuck on you should be able to see it. Alternatively go for a short drive (when its chugging) and then pull out a spark plug to see if its wet or has carbon build up. If the choke was stuck on it should take a little longer to heat up the motor, providing the same amount of accelerator is applied.
Post up how you are going and I'm sure people will continue to offer suggestions. And remember any different engine noises are all helpful when diagnosing.
What my garage isn't messy........Well chaos is a form of order isn't it?
i"ve had a full service carried out, but the problem is still there. The mechanic says the choke is working fine, but I am not convinced. I am considering diabling the choke as outlined in Muir's idiots manual. Any comments?
You should be able check the choke by looking at it
When cold it should spring closed
After 5 minutes of running the choke butterfly should be open
Dont go disabling the choke until you are 100% positive
This is one thing i dont really agree with John Muir on
Futue te ipsum!!!
Thanks Bizarre, I took the air cleaner off and yes the butterfly opened very slowly over the 5 minute period, so I guess it's working OK.
So the timing is good, the choke is good, but my problem rmains.
Does anybody have any other ideas??
Have a look at the idle jet and the main jet incase there is a dilbury in there.
Should be easy to access on the side of the carb without getting fuel everywhere.
westi wrote:That's mad Alan.
Also any fuel filters or screens.
I think there is one in the bottom of some fuel tanks too!
westi wrote:That's mad Alan.
Hello!
What is a chug?
Do you mean a flat spot? The engine hesitates & splutters for a bit then goes OK once the revs build up- the 009 is famous for that! Is it a recent addition?
Do you mean a misfire? ie it runs on 3 or even 2 cylinders instead of 4.
Can you reproduce it standing still or is it only when on the move? Can you test if it's worse uphill vs on the flat?
What's a full service?
How's the idle hot & cold?
"n short the car wont run smoothly untill engine temperature has increased, way beyond what it normally should. This is only something that has developed recently, so I am at a loss as to what the problem is. Any help would be appreciated."
HMMMMMM! A lightbulb just went on!
Recently: like since winter started?? How cold is Brisvegas this year?
I'll back a blocked heat riser- that pipe under the inlet manifold. They soot up & stop the exhaust gas passing & hence become VERY slow to warm up. When the choke is operating, it will mask the symptoms & that could be why it OK at 1st. Also, that Donkey D*ck going up to the air filter from the heater box goes via a Summer/Winter Portal. You can change it with a lever. Make sure it ONLY sucks hot air.
Easy to diagnose. Get a hot air gun ( NOT A BLOW-TORCH THERE'S BLOODY FUEL AROUND!) or the sig other's hair drier, or just put a fan heater going on it while you have brekky- & warm up the manifold until it's literally too hot to touch. Quickly jump in then give it some stick.
If that works let me know & I'll tell you how to fix it with an old clutch cable & an electric drill. NOT FUN!
Thanks Geodon,
I will try and answer your questions.
The car idles well, when I accelerate the car hesitates (feel as if the car is jerking back and forth). I cant produce the same symptom when the car is standing still, I can rev the engine freely when it's parked in my driveway. The problem is no worse going up a hill compared to driving along a flat stretch. What I mean by a full service is timing set, new plugs, points, carby tuned etc. pretty much the works.
This is something that has developed over the last year or so. The heat risers have been blocked off by the previous owner, and used to run great. the problem also was happening in summer time, so I doubt it's the heat riser.
Mine does that if it's left outside in the cold. Maybe moisture in the dissy?
Thats not rust, it's ah ... orange primer ... yep that's what it is ...
Ok that's clearer now.
The fact it spins up OK in the drive suggests fuel delivery is not a problem. If the heat riser was it, it would play up in the drive too as the fuel wouldn't atomise properly. Blocking off the riser in ur climate is prob OK tho.
Good idle = no vacuum leaks
I'd be looking at high tension.
The plugs & points are new so work backwards.
Can you borrow another set of HT leads, dist cap & rotor from someone to do a trial run? Or just replace them??
Also coils do funny temperature related things too. Can you boorrow one for a test?
I started the car today, and drove off with the usual problem, but it wouldn't go away after the engine had warmed, like it did last week. In other words the problems got worse. Would this be bacause I ran the engine yesterday without the air filter on?
The engine has a new coil, I have a spare set of HT leads, so I might try them.
Air filter?
How did it run without it??
I had a prob on a 1600TP Kabrio that was a loss of power. Stumped for for weeks.
Couldn't find it.
Mr Bug's dyno couldn't find it either.
In desperation, i tried a different carby & took off minus the filter coz I was in a hurry. Problem cured! Put the filter back on, problem came back. Would you believe that summer/winter flap I mentioned above had detached itself from the lever & flipped BACKWARDS and actually choked off the inlet- ie the eng was not getting enough air!! Outside looked perfectly normal- the lever was wher it should be but the flap was blocking ALL air to the filter.
I don't like coincidence. Have a close look at the air filter. You would not have done any damage in a city environment to drive unfiltered.
Just put another set of used HT leeds in, didn't help, problem still there.
I didn't give drive the car without the filter, should I give it a go.
Also that summer winter flap doesn't exist on my car, never had one since I've owned it.
Yeah! Give it a go- 1 more thing eliminated.
No flap?? Dunno! They were on the 40hp's I think. With a weighted lever that preferentially favoured the hot air input but could be locked out or over-ridden by high air-flow. Maybe it's internal or self regulating on ur model?
I had my car towed to the mechanic today as it was becoming undrivable. He finally sorted the problem, the solinoid in the carby throat was stuffed. Thanks everbody for your contributions.
