First Breakdown

[Igeo]

Closing this one out for now too. Wound up replacing the Hall sender and the coil. I tightened up the 0.060" end play on the distributor shaft too using the fiber washers sourced from advice gotten here and was able to achieve about 0.008" end play. Really running well now. Thanks for the guidance on this one.
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1987 Westfalia 2.1 WBX Manual

[Igeo]

The same apparent issue ruined another attempted vacation yesterday. We left from Oakland and were almost over 7,300 foot Echo summit when it started cuttting out. Not a miss, not fuel starvation but a sudden and moementary cutting out with corresponding tach drop but no warning lights. When this happened in Jackson 2 months ago,we were towed home. I found a broken Hall sensor plug so I repplaced it and the coil. My bad for not definitively identifying the root problem, but the van started right up and ran well on a 15 minute feeway test drive.

Yesterday, as it was bucking, we pulled over by a snow play area and it died and would not restart. All connections and grounds were solid. Fuel pump cycled normaly when the ignition was switched on. The ingition switch is 6 months old. The air flow meter has the capacitor upgrade too by the way.

After about 30 minutes of checking things and discussing options, I tried starting again. Normally I never touch the throttle when sarting, hot or cold at sea level. This time with my foot to the floor it started, cleared out some unburnt fuel and I held it at about 2,500 rpm for about 30 seconds. It was running normally. I started slowly backing out of the throttle to see if it would idle, and it suddenly died when passing about 1,500 rpm with a corresponding tach drop. Just like switching off the ignition. I repeated this behavior a couple of times. We restarted with a wide open throttle and keepng it running, turned around and headed down the mountain, tails tucked firmly.

Drove straight home, but with at least 8 instances along the way with the same apparent momentary igniton drop out, but with momentum we made it home. It idled perfectly in the driveway (of course).

One other clue. This time we noticed a loud, rough rattle/buzzing in a location that sounds to me like it's in the cluster. I thought I had an oil pressure issue at first but the gauge indicate otherwise. I have never heard the low oil pressure buzzer, so I don't really know what it is supposed to sound like. The bucking seemed to correspond with the noise while driving, but not every time. To further muddy the waters, my wife is convinced that the buzz comes from under the driver seat where the Go Westy battery isolator lives. This set up has not given me trouble. From the drivers position, it sounds like the buzz is behnd the dash 100%. My wife is convinced it's under the seat.

Questions:

Does the sudden shut off when backing out of the thottle as described above suggest an air fow meter issue?

Can a loose connection or failing relay in the Go Westy battery isolator create a power drop out in the ingition?

What is that low oil pressure buzzer supposed to sound like?

Can a bad tach cause this behavior?
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1987 Westfalia 2.1 WBX Manual

[crazyvwvanman]

It is rare, but it has happened that the tach causes ignition failures.

VERY quick and easy to test for this though. Let me know if you want to pursue it.

The air flow meter can't make the tach needle drop to zero instantly while driving.

Mark

[Igeo]

Disconnect the tach leads at the coil?
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1987 Westfalia 2.1 WBX Manual

[crazyvwvanman]

Yes, at the coil. Post a photo of the green wires at your coil.

Normally there are 2 green wires to a white plastic connector housing.
One green wire is FROM the ECU to fire the coil.
The other green wire goes to the dash cluster where it feeds both the tach and the oil pressure warning circuit board.

Look at how the white plastic connector plugs onto the coil.
Unplug it and see that each green wire goes to a female pin in the housing. Then move the housing so only the larger green wire's female spade plugs back onto the coil male spades the connector was pulled from.

Mark

[Igeo]

So we want to keep the (larger?) ECU to coil wire connected, but not the tach/oil pressure wire. That seems like a good route to follow up on since the buzzing behind the cluster, the tach dropping and the cutting out appear related.
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1987 Westfalia 2.1 WBX Manual

[Igeo]

What do you think this tap might be for? Doesn't look factory.

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1987 Westfalia 2.1 WBX Manual

[MarkWard]

You'd have to follow the wire. Its not stock, but something that is looking for an rpm pulse. That could certainly ground the coil out if connected to some gizmo.
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[Igeo]

Double post deleted.
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1987 Westfalia 2.1 WBX Manual

[crazyvwvanman]

Perhaps that wire was added for aftermarket cruise control.

Mark

[Igeo]

It does have a non-functioning CC.
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1987 Westfalia 2.1 WBX Manual

[crazyvwvanman]

I would unplug that wire from the green one.

Mark

[Igeo]

The aftermarket cruise control was not functioning, so I removed the entire rats nest of wiring, cable and control box. And I disconnected that signal wire (?) from the coil. I'm also going to pull the cluster to disable the oil pressure warning buzzer since I have a gauge. I know that box control box was always powered up with the key on since it has red indicator lights. Good riddance.

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1987 Westfalia 2.1 WBX Manual

[pdm777]

Following.
been chasing this issue for years.

crazyvwvanman- Why would removing the tach wire from the coil resolve this?
Interested to understand the cause/effect of the tach on this issue.

I've had the tach instantly drop as the engine misses, then dies.
It usually happens after about 3 hours of driving.
It always restarts after resting for 20 minutes.

Replaced my coil, plug wires, rotor, etc.
So far, in the last year or so, many long trips, no problems.
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1990 Westy Full Camper

[pdm777]

MarkWard--

Please give details of how to add the MSD unit and coil !

MarkWard wrote:
MSD unit and MSD coil to try and pin down the problem. The MSD is essentially a standalone spark system. Using the signal from the ECU that would fire the coil, now notifies the MSD to fire. Essentially turning the ECU coil driver into a relay and removing all loads.
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1990 Westy Full Camper

[crazyvwvanman]

The point of my reply was that it is simple and easy to bypass the green wire that feeds the dash cluster and eliminate the remote chance that something on that dash feed wire is the cause of problem.

Mark

[MarkWard]

Adding an MSD is fairly straightforward, but the one we installed on a vanagon was an attempt to isolate why the stock coils we’re failing. It was impossible to duplicate even on the dyno. Adding the MSD did solve the coil failing problem on this van. Can’t tell you why. The owner is stoked to have the van reliable again.

It’s an expense you shouldn’t need. You really need to diagnose when the engine won’t run. The goal is to isolate if it’s fuel or spark. Pre connect a fuel pressure gauge and have your timing light ready. The gauge will let you see if you have fuel pressure and the timing light is an easy safe quick way to test for spark.
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[pdm777]

Thanks for the replies.

I have installed a fuel pressure gauge and Air Fuel ratio gauge,
the problem hasn't occurred since swapping coil a while back.

I recall there was a way to wrap a neon (?) bulb around
a spark wire and it would flash when energized.

Gotta look into that, I'd rather not carry my timing light,
vans too heavy as it is
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1990 Westy Full Camper

[valvecovergasket]

Just carry a spare plug, and ground it against the block to test spark. Even easier than a bulb or timing light
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MegaSquirt resource - SpitfireEFI.com

gone, but not forgotten: '83 tdi westy - swap thread

[MarkWard]