Bucking, lurching leads to no camping and bummed out kids

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SlowLane
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by SlowLane » Sun Jul 29, 2012 5:49 pm

aopisa wrote:Just wanted to say, no points, no dwell. Running with electronic points replacement.
Yes, understood. But it's worthwhile knowing whether your points replacement is in fact giving you acceptable "dwell", even if it can't be adjusted. It does switch power to the coil on and off just as the points do, at what one hopes is the correct duty cycle, but don't take it for granted.
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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Sun Jul 29, 2012 6:35 pm

Amskeptic wrote: Ever do a quicky centrifugal advance lubrication? Remove distributor, pry out the little metal "window", lubricate the pivots as you rotate them past the window and twist the rotor in relation to the drive dogs back and forth and back and forth, I think you already did the felt wick.

Reinstall distributor. Manually insure the rotor and shaft is fully counter-clockwise in relation to the now engaged distributor drive dogs. Start engine at whatever idle it is, and set timing to 4* BTDC exactly at idle !!! without revving the engine!!! ever!! we are trying to keep weights fully in. If you accidentally do rev engine, merely shut it off and turn rotor counter-clockwise, start engine again no revving, time it at 4* BTDC. Set idle speed to a warm egine 950 minimum rpm. There! No variables! Now rev to 3,400 rpm and see what your high speed timing is. Hopefully I did compensate for your worn distributor and you found 28*. Let engine return to idle. Is it 4*? Good. Is it 12 with a fast idle? Need to disassemble distributor.
Colin
Will check dwell on electronic points replacement.

I don't have my Bentley with me right now. Do I just remove the distributor or do I have to position the engine at no. 1 TDC?

When I reinstall it, do you mean to give the rotor and shaft a twist by hand to make sure it is far as it will go CCW? What is a drive dog?

Should the 4 degrees BTDC be with the vacuum hose off? Do I leave it at 4 degrees when complete?

Will report back when complete.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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SlowLane
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by SlowLane » Sun Jul 29, 2012 7:18 pm

aopisa wrote: Will check dwell on electronic points replacement.

I don't have my Bentley with me right now. Do I just remove the distributor or do I have to position the engine at no. 1 TDC?

When I reinstall it, do you mean to give the rotor and shaft a twist by hand to make sure it is far as it will go CCW? What is a drive dog?
I had avoided recommending the you pull the distributor, based on your apparent lack of familiarity with the system (ie. never having replaced points before), and because there are too many ways that this procedure can go wrong if you're not prepared.

If you have the time and inclination, I recommend reading Ratwell's article on the ignition system for some good background information.

Normally you could just remove the distributor as it is, because the distributor drive pinion should remain in the case and keep the ignition properly indexed to the engine (via the "drive dog", a little metal tab that sticks down from the bottom of the distributor shaft. It's offset so that it only engages the pinion one way), but there's a possibility that the pinion could pull out with the distributor, in which case you could be in for some grief. So it would be prudent to put cylinder #1 at TDC first.

The window Colin refers to is a litte oval-shaped metal piece pressed into the side of the distributor body. Gently pry it out of the body, taking care not to damage it, as you will want to put it back in when you're done. If you then turn the shaft of the distributor you will see springs and weights and things rotate past. You will want to clean and lubricate those as best you can. I have successfully cleaned up sticky distributors with nothing more than WD-40, but I doubt that is what would be best for a long-term solution. I'm sure Colin has better advice on exactly what to use in this situation.

When you reinstall the distributor, you do your best to line up the drive dog with the matching slot in the pinion, then press gently down on the distributor body as you turn the distributor shaft until you feel the dog engage with the slot. The distributor body should suddenly sink a little further into the case when this engagement happens, and the shaft should become harder to turn then (you should then feel the "springy" action of the centrifugal advance). At this point turn the distributor shaft/rotor as far CCW as it will easily go (don't reef on it). This pulls the weights in to their fully-retracted (ie. zero-advance) position, which is where Colin wants you to start.
Should the 4 degrees BTDC be with the vacuum hose off?
Hose off, yes.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Mon Jul 30, 2012 8:33 am

SlowLane wrote:
aopisa wrote: Will check dwell on electronic points replacement.

I don't have my Bentley with me right now. Do I just remove the distributor or do I have to position the engine at no. 1 TDC?

When I reinstall it, do you mean to give the rotor and shaft a twist by hand to make sure it is far as it will go CCW? What is a drive dog?
I had avoided recommending the you pull the distributor, based on your apparent lack of familiarity with the system (ie. never having replaced points before), and because there are too many ways that this procedure can go wrong if you're not prepared.

If you have the time and inclination, I recommend reading Ratwell's article on the ignition system for some good background information.

Normally you could just remove the distributor as it is, because the distributor drive pinion should remain in the case and keep the ignition properly indexed to the engine (via the "drive dog", a little metal tab that sticks down from the bottom of the distributor shaft. It's offset so that it only engages the pinion one way), but there's a possibility that the pinion could pull out with the distributor, in which case you could be in for some grief. So it would be prudent to put cylinder #1 at TDC first.

The window Colin refers to is a litte oval-shaped metal piece pressed into the side of the distributor body. Gently pry it out of the body, taking care not to damage it, as you will want to put it back in when you're done. If you then turn the shaft of the distributor you will see springs and weights and things rotate past. You will want to clean and lubricate those as best you can. I have successfully cleaned up sticky distributors with nothing more than WD-40, but I doubt that is what would be best for a long-term solution. I'm sure Colin has better advice on exactly what to use in this situation.

When you reinstall the distributor, you do your best to line up the drive dog with the matching slot in the pinion, then press gently down on the distributor body as you turn the distributor shaft until you feel the dog engage with the slot. The distributor body should suddenly sink a little further into the case when this engagement happens, and the shaft should become harder to turn then (you should then feel the "springy" action of the centrifugal advance). At this point turn the distributor shaft/rotor as far CCW as it will easily go (don't reef on it). This pulls the weights in to their fully-retracted (ie. zero-advance) position, which is where Colin wants you to start.
Should the 4 degrees BTDC be with the vacuum hose off?
Hose off, yes.
Is measuring dwell for electronic points replacement the same as with points? Connect red test lead to (-) post on the coil and black to ground? If so dwell = 55 degrees

Started up this morning with some difficulty. It was idling low again, at or below 650. Adjusted idle up to 850-900 range. Timing remained constant at 7.5 and 28.

Bentley says "remove bolt that holds the distributor bracket to the crankcase". That is the one directly below the distributor vacuum canister? Is that all for removing the distributor?

TDC no. 1 is where the rotor is pointing at the no. 1 wire position? There is also a notch on the rim of the distributor cap in that location.

Is this procedure leading to a possible solution of the original issue or just addressing another potential problem?

Sorry, but I want to double check before I potentially create a condition worse than the one I already have.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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Amskeptic
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by Amskeptic » Mon Jul 30, 2012 8:41 am

aopisa wrote:dwell = 55 degrees
Timing at 7.5 and 28.
Dwell is a little high. You can adjust the proximity of the pick-up to the trigger wheel with the provided plastic shim. If you do not have the plastic shim, you will have to guess. I tink! you move the pick-up unit slightly further away to reduce the dwell. Call Pertronix and ask.
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Mon Jul 30, 2012 9:10 am

Amskeptic wrote:
aopisa wrote:dwell = 55 degrees
Timing at 7.5 and 28.
Dwell is a little high. You can adjust the proximity of the pick-up to the trigger wheel with the provided plastic shim. If you do not have the plastic shim, you will have to guess. I tink! you move the pick-up unit slightly further away to reduce the dwell. Call Pertronix and ask.
I called Pertronix tech support. They told me that dwell cannot be adjusted as it is set inside the unit and that 50-55 is within their range. Since I am out of my league here, I'm not sure what that means for my bus or this is just a load of BS. I don't even know if the unit I have installed is actually Pertronix or some other brand, but that should not make a difference I think.

I am getting pretty close to have to scrap taking the bus to destinations West if I can't fix this issue soon. I leave in a little over a week. It's starting to look like it's going to have to be the Jetta wagon. A tighter smoother ride, but certainly not as fun or memorable....
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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56ovalbug
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by 56ovalbug » Mon Jul 30, 2012 12:22 pm

Since your problem comes and goes and your bus generally doesn't run well I doubt your problem is distributor related - more so now that the timing is correct. The dwell reading sounds correct for a electronic set up so I wouldn't worry about it. Sounds more like either a fuel delivery problem - like crap in your tank or fuel lines rotting on the inside plugging things up or an electrical problem like a lose or corroded connection or a wonky cylinder head sensor. A good start would be to unplug the connectors one at a time to make sure they are all in good condition and tight with no corrosion. If you see any green residue on any connector then that's corrosion and must be cleaned off. I always like to use a small dab of dialectical grease on all my FI connections.
Joey

'56 Beetle|'65 Beetle|'74 Bus|'79 Panel

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Mon Jul 30, 2012 12:34 pm

56ovalbug wrote:Since your problem comes and goes and your bus generally doesn't run well I doubt your problem is distributor related - more so now that the timing is correct. The dwell reading sounds correct for a electronic set up so I wouldn't worry about it. Sounds more like either a fuel delivery problem - like crap in your tank or fuel lines rotting on the inside plugging things up or an electrical problem like a lose or corroded connection or a wonky cylinder head sensor. A good start would be to unplug the connectors one at a time to make sure they are all in good condition and tight with no corrosion. If you see any green residue on any connector then that's corrosion and must be cleaned off. I always like to use a small dab of dialectical grease on all my FI connections.
Since I am running through a lot of possibilities, checking fuel pressure was next on my list. I would assume that if one or more of the above was true, I would find variation in fuel pressure?

I did test the TS ll yesterday. The Bentley states 2500 ohms at 68 degrees. It happened to be 67 yesterday morning and the sensor (newly replaced) tested within spec. That doesn't mean that it still might misbehave as the bus warms, although I have tested it by unplugging it and grounding the wire leading to the ECU without any change in the condition.

I have checked a lot of the FI connections, but not all. Will continue.

This issue is helping me get more familiar with my bus and as I go through things, I am eliminating (I hope) what isn't the problem. At the same time it's frustrating not being able to drive it or get it out on the open road this summer.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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Re: Bucking, lurching leads to no camping and bummed out kid

Post by 56ovalbug » Mon Jul 30, 2012 12:48 pm

I hope you find the problem and it's the real problem so if you do decide to take it on your trip you'll have piece of mind knowing that the bucking and lurching won't return again.
Joey

'56 Beetle|'65 Beetle|'74 Bus|'79 Panel

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SlowLane
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by SlowLane » Mon Jul 30, 2012 1:05 pm

Y'know, we've gone through an awful lot of possibilities. Here's one we haven't explored much: how clean is your fuel?

You initially said that this was a 3-season driver, so if you've just taken it out of storage there could be a significant amount of water condensed in the tank, which will definitely cause running problems.

I've recently become aware of a product called Mr. Funnel, which claims to filter out water and debris from all kinds of fuels. If you have the skills to drain your tank and run the fuel through a Mr. Funnel, it might help. Alternatively, a dose of Methyl Hydrate (aka. "dry gas") might do the trick.

re: the dwell. I doubt it's an issue. Not surprising Pertronix gave you that line. Assuming you have a Pertronix, the link I gave to Ratwell's dwell adjustment procedure a few posts ago might be of interest, if you have the patience for it. Personally, I don't like Pertronix for a number of engineering-related reasons.
Bentley says "remove bolt that holds the distributor bracket to the crankcase". That is the one directly below the distributor vacuum canister? Is that all for removing the distributor?
Yes. No, you also need to disconnect the wires to the coil (in case that wasn't obvious).
TDC no. 1 is where the rotor is pointing at the no. 1 wire position? There is also a notch on the rim of the distributor cap in that location.
Yes.
Is this procedure leading to a possible solution of the original issue or just addressing another potential problem?
Yes, quite possible. The improvement in engine response when the advance mechanism is working smoothly has to be experienced to be believed, if you've been running with an original distributor with original 30-plus year-old grease in it.

One more thing: if you don't know when that last time your brake fluid was flushed/replaced, you should seriously consider doing this simple maintenance before you embark on any long adventure. Brake fluid absorbs water, and when it does its boiling point temperature decreases. The last place you want to discover that your brake fluid's boiling point has diminished is while you're careening down a mountain pass. Happens to many ill-prepared RV owners every year.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Re: Bucking, lurching leads to no camping and bummed out kid

Post by Xelmon » Mon Jul 30, 2012 2:08 pm

SlowLane wrote:I've recently become aware of a product called Mr. Funnel, which claims to filter out water and debris from all kinds of fuels.
Sorry to go off topic, I wouldn't trust that thing. Even if I used a multi-fuel! It has snake-oil written all over it.
/bahuselesscrap

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Mon Jul 30, 2012 2:37 pm

I don't think fuel is the issue. I stopped driving it last December. Filled it up and put in some fuel stabilizer. Started driving it about April/May this year and almost daily since then. So I have run through several tanks of gas. My fuel gauge only reads 3/4 when full. I fill up generally when I dip below the 1/4 mark which is more like 1/3 to 1/2 tank. Even though I have several gallons left, it still makes me nervous to drive in the red zone on the gauge. I don't think it's crap in the tank since again the problem is predictably intermittent if that makes sense. Plus, the fuel filter did not look terrible when I cracked it open. It might be the pump acting up when called upon to deliver? I still want to put a gauge on it (tomorrow) just to get a base line.

While checking some connections, I pulled the plugs out of the double relay and the left one looks pretty gunked up.
SlowLane wrote: Yes, quite possible. The improvement in engine response when the advance mechanism is working smoothly has to be experienced to be believed, if you've been running with an original distributor with original 30-plus year-old grease in it.

One more thing: if you don't know when that last time your brake fluid was flushed/replaced, you should seriously consider doing this simple maintenance before you embark on any long adventure. Brake fluid absorbs water, and when it does its boiling point temperature decreases. The last place you want to discover that your brake fluid's boiling point has diminished is while you're careening down a mountain pass. Happens to many ill-prepared RV owners every year.


I looked inside the distributor today and it looks very oily/greasy in there.

Yes, brake fluid was on my list. DOT 3 or 4?
56ovalbug wrote:I hope you find the problem and it's the real problem so if you do decide to take it on your trip you'll have piece of mind knowing that the bucking and lurching won't return again.
My thoughts exactly!
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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SlowLane
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by SlowLane » Mon Jul 30, 2012 5:06 pm

aopisa wrote:Yes, brake fluid was on my list. DOT 3 or 4?

What does it say on the brake reservoir cap? I think it's DOT 4 on my Vanagon.
snake-oil-skeptic wrote:I wouldn't trust that thing. It has snake-oil written all over it.
I agree that the video presentation on the web-site has that snake-oily character, but hey, it's just a very fine filter. How complicated can that be? It also has an appreciable number of positive Amazon reviews.

I'm going to risk twenty bucks and pick one up tonight. I have a quantity of gasoline-contaminated water from when I replaced my fuel tank (Colin said "fill the tank with water to prevent it from becoming a bomb". Yeah, but now I have a couple of gallons of very smelly water that I can't dispose of easily. At least, not in California.)
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
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56ovalbug
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by 56ovalbug » Tue Jul 31, 2012 3:49 am

I believe you want DOT 3 brake fluid.

If you suspect water/moisture in the gas tank then just throw a cup full of gas line antifreeze or methyl hydrate in the tank. I do this several time a year just to make sure I have no moisture build up in the tank.
Joey

'56 Beetle|'65 Beetle|'74 Bus|'79 Panel

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Tue Jul 31, 2012 5:43 am

56ovalbug wrote:I believe you want DOT 3 brake fluid.
Ratwell says DOT 3 or 4. Apparently DOT 4 has a higher boiling point.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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