Ignition problems

[Greg Schoolbus]

Hello Samba -
I'm unable to figure out what's going on with my 1974 bus with a 1973 type 4 engine. Single progressive carb with a 009 no vacuum advance distributor. I'm not a mechanic, so I apologize in advance for my clumsy dialect.

It's been one thing after another for the past month after it had been running like a top quite a few months. First thing was the electronic ignition burned up and my mechanic said the coil also needed to be replaced. He replaced the coil and installed new points and a new condenser (which he claims is the way to go over an electronic ignition, and I understand there is disagreement out there about this idea).
I took 3 trips back to him in the week after because it was running so rough (no power, coughed and sputtering). A retired VW friend of mine figured out (I think?) this mechanic had the timing way to retarded, and got it running decent for me. That was two weeks ago. (One point of confusion I have found is that the books and charts that refer to the correct timing as I understand it aren't necessarily meant for my rig as the bits and pieces have been cobbled together over the years. Can I even trust the timing charts in the books for my CB 1973 motor??)

Now it is dying on me, can't keep it running. And it backfired 3 separate times in the past two days. My retired mechanic friend (he worked on VWs for about 10 years back in the 70s) says he is confident it is ignition issues, and someone needs to "scope" the distributor and coil. One problem I have is I literally can't even find an air-cooled mechanic within 45 miles of me. The guy who replaced the coil and condenser is kinda suspect to me, as the car comes back smelling like weed and they seemed to struggle to diagnose the problem.

Can anyone lead me with some ideas as to how you would approach this problem?

I am super appreciative in advance of any advice you have. I am located in Ripon, California. I'll try to include some pics below of my engine compartment so you get the idea of how this is set up. These pics are old, before the coil was changed out.

_________________
1974 Transporter
Zen and the Art of Motorcycle Maintenance: "The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed."

[SGKent]

so the first thing is to be really concise in what you want help with. If you want to do a narrative type question like you did, just be aware that threads that go like that are hard to follow without devoting a half hour to study them -> example of what not to do-> "I was on the way to get groceries for the house, decided to stop by and pick up some dog food. The people in the parking lot were being their usual pushy jerks. I got gas the the other day and it was so expensive so my mind was on that too. My wife asked me to get some specific groceries so I had to go back to the bus to get the list. Some guy was talking to me and I wasn't paying attention so I set my keys down and now I don't know where they are. They were on their own yellow fob so I should be able to see them but I don't. So I went back into the store to get the groceries that I remember but I am still locked out of my car. Anyone have ideas?"

Example what to do: "I am locked out of my bus and need help getting back in it. I am at the store and can't find my keys."
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"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[Greg Schoolbus]

Gotcha. Here's the question:
My bus keeps dying on me, can't keep it running. And it backfired 3 separate times in the past two days. My friend says he is confident it is ignition issues, and someone needs to "scope" the distributor and coil.

Can anyone lead me with some ideas as to how you would approach this problem?
_________________
1974 Transporter
Zen and the Art of Motorcycle Maintenance: "The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed."

[Bnanwel]

Adjust the valves; check for damage in distributor(points, rotor, distributor cap); gap points; set timing; report back.
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‘72 Karmann Ghia Conv.
‘73 Karmann Ghia Coupe
‘74 Karmann Ghia Coupe
‘70 Deluxe
‘72 Deluxe

[SGKent]

[timvw7476]

Classic '73-'74 'Twilight Zone' Issues.
problem is VW put a dual-can-dual advance distributor on those VW buses. So the Bentley manual 'reads wrong' if you have a 009 or a DVDA distributor that has long since experienced a failed advance or vacuum canister failure & been rigged to get by without the vintage emissions detritus.
If you have 009 distributor, set it up as though it is a Bug or any other air cooled device running 009. You do need a timing light to confirm the spark events. meaning the idle timing event, anywhere from Top Dead Center (TDC on the #1 cylinder power stroke, to 7.5 degrees Before Top Dead Center (BTDC).
The other timing event is measured at 3,400rpm or so. You want to see the strobe light trigger at 28-30 degrees Before Top Dead Center. Then return to the previous idle speed . You need a legible timing scale bolted to the fan housing. The 1973 ones were all painted. White background with black numerals With a tiny red dot where the 'at speed' spark event should occur. <<these also tend to fade with time & can't be seen well, the later black plastic scales hold up better.<<
The reason to use a timing light/gun is to confirm you're at a safe spot at 3.400rpm. The liquid cooled cars were happy with 36 degrees or so of advance. That setting will burn a valve & do bad things to an air cooled engine. Always keep it so 30 degrees BeforeTDC at 3,400rpm or less.
The factory setting for a 2.0L is 7 1/2 degrees BTDC @ idle. 28 degrees BTDC at 3,400rpm. There's also an extra boost in timing advance via the 2.0L distributor vacuum can. But that's another story.

[Greg Schoolbus]

[Greg Schoolbus]

[/quote]

there are two kinds of backfires. One is back up thru the intake plenum and the other is out the exhaust. Different causes. Which one does your bus have?

[/quote]

I don't know how to tell the difference.
It's sharp and loud, like a gunshot.
_________________
1974 Transporter
Zen and the Art of Motorcycle Maintenance: "The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed."

[SGKent]

[Greg Schoolbus]

[Greg Schoolbus]

[SGKent]

[Greg Schoolbus]

[SGKent]

I guess she could have knocked dirt free in the carb or something. Not a common thing.

I might make sure all the plug wires are pushed down tight ON THE Distributor, and that the distributor is fully seated. If he did not get the wires all the way in, or if the drive dog is barely catching the drive gear it could occasionally skip. There should be no gap at the bottom of the distributor and the clamp should be up tight against the bottom of the distributor. If it occasionally jumped out and then caught again, that would make for an intermittent backfire, stumble, loss of power. A quick look with a flashlight will answer that question.

If it is not that then I would replace the condenser on the distributor. The poor quality today of those makes them suspect when the ignition is doing strange things. Probably I would replace it with one of these: https://www.napaonline.com/en/p/ECHEP433 The page may say alternator or ignition condenser but it is an ignition condenser.
_________________
"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[Wasted youth]

Are you planning on learning how do keep your bus running correctly, or do you plan on taking it to a mechanic? That is not a sarcastic question. That question needs to be answered before people start giving you advice. Because your mechanic will ignore internet advice, but if you don’t understand our advice, nor do the work yourself, then it will do you no good. You’ll make no progress.

If you are planning on doing the work yourself, you’ve already been given a full day’s worth of tasks for a new home mechanic from the advice given in the last half dozen paragraphs.

Based on how I perceive your posts, I don’t think you’re prepared to do those tasks yet . But if you have completed those tasks, you should further this discussion. If you are talented enough to figure out your sprinkler system in your yard, change out a dishwasher, and change the oil and rotate your tires by yourself, I can assure you and believe in you that you are talented enough to do this work. Don’t give up just because it gets weird, complicated, or frustrating. You can make your bus perform very well with a decent collection of hand tools that can be bought at Home Depot, O’Reilly’s and Harbor Freight.

You don’t need a Bear engine analysis rollaway cart, you don’t need $75,000 worth of Snap-On Tools, and you don’t need to give up when the going gets rough. I mean, you can if you want. I’m just saying you don’t need to.

You DO need a fairly level place to do the work, you need to have the capacity to understand that you’re gonna have to read instructions and service manuals that make absolutely no damn sense, which means that you’re gonna have to stop that reading and do Internet searches on just what the hell it is these old books are trying to tell you. AND you need to be able to walk away from it and go to your day job with shit torn apart everywhere and not having it get ripped off by tweakers, or your dog pissing on it.

For what it is worth, I have that same bus. I have a 1973 bus with a 1700 cc stock engine that is worn out with sad compression and leaks enough oil making Harley Davidsons jealous. I rebuilt the Type 3 automatic transmission, as well as a complete front end rebuild. I am not an auto mechanic. I’m a home mechanic with a fire trap of a garage, a forgiving wife and two warnings from Code Enforcement regarding an unnecessary collection of automobiles.

My bus also has the incorrect Weber DFAV carburetor and it is properly jetted from parts by Redline Incorporated. I have the proper distributor, I think it is the 205S but I have not looked at it in two years. I’ll have to check I guess.

My engine lays claim to a whole box of dirty parts for the correct dual carburetor system, but honestly, I like fuel injection better so when I finally pull out that junkyard motor, I will be replacing over the 2.0 fuel injected engine.

In my earlier experiences, I just about ruined that engine because I had bad ignition timing and was fighting that stupid Weber carburetor…. trying to follow the Bentley.

Until the point that I took the bus out of service to do all the bodywork, it ran up and down Highway 99 doing 70 miles an hour and never got hot. I’ve been camping over the Mojave and after I rebuilt the front end, I can keep it driving straight with a fart.

I know you’re in Ripon, and I go through there once a week, but I live down in Kingsburg, and I work in San Francisco stumbling over hypodermic needles, piles of human shit and tipping over fentanyl freaks with my balled-up Starbucks coffee cups tossed at them from the locomotive.

So I would like to stop by and help you out, but the sad reality it is I actually do love my wife and kids and my time is extremely valuable. Send me a private message and maybe we can work something out to where I can stop by for a couple of hours or something.

You have no reason to give up. It’s frustrating as fuck, I know that. If you take anything away from my long winded, self-absorbed monologue here, take away this: An elephant is eaten one bite at a time.

Do this: find Top dead Center on number one cylinder, using the wooden stick trick in the spark plug hole. Set your distributor with your points gap and a test light on the number one cylinder. Learn how to do those two tasks accurately. After that, adjust the valve lash. Do not get distracted by any other task.

[Wildthings]

The distributor cam needs to be properly lubed, when everything is done right you can go 12,000 miles without touching your distributor, when done wrong you can have problems in only a couple of hundred miles. I still have a shop size tube of GM distributor grease from the good old days, and Bosch distributor grease is still available through some vendor. Some people use either dielectric grease, silicone grease like Super Lube, or just regular lithium based grease, but I would avoid using the lithium base grease as IMO it will migrate too much when it gets hot.

You can also apply a tiny drop of oil to the pivot for the points with a tooth pick, this is typically not necessary with today's points but was way back when. If your mechanic put in Bosch points, they may have failed as they are or at least were very low quality for a while, check that the wear block has not broken off and thrown the gap way off. I have been running Echlin ventilated points from NAPA for a long time now and have been quite happy. I spent a few hundred dollars a few years ago and bought enough Echlin points to keep all my old rigs running for the remainder of my life.

[Greg Schoolbus]

[Greg Schoolbus]

[Greg Schoolbus]

[SGKent]

there is a lot of debris at the base of the distributor. I am puzzled by why that would be on a fresh install. Looks like a shard of carpet is stuck in there too. I can't tell from the photo if it is fully installed or not. The bracket should sit flush on the case and the bottom of the distributor sit flush on the bracket. The condenser can also be at fault. Lots of problems with them the last couple years.

You can turn the rotor to see if the distributor is fully seated. If not it will spin if you pull up just a little on it. Do not turn too hard of the nub in the bottom that locks in in place will break off. You can also look at the bottom of the rotor to be sure that has not happened already.

When you set it to say 30 degrees BTDC at 3400+ RPM, that is with the hoses off.
_________________
"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin