BOSTIG: Frustrating Engine Dying Problem Solved At Last

[jyl]

I think I have FINALLY fixed what ails my van, and thought I'd come tell you about it, because it was slightly weird, to me anyway.

The various problems are partly explained here

https://www.thesamba.com/vw/forum/viewtopic.php?t=713565&highlight=jyl

However, there were, in the end, a couple different problems. So I'll describe the specific problem that I just fixed.

It is an older Bostig v2 conversion. The engine started dying for no obvious reason. Sometimes it would restart and run fine, other times not. The OBD scanner sometimes gives a “coil” code. I found that replacing the coil fixed it temporarily but after a while the problem would recur.

Then it started dying sometimes when I lifted off the throttle, like when approaching a red light. It would restart fine, I could even dip the clutch and bump start if I had the road space.

And then it started wanting to die when backing out of a parking space. I had to use higher revs and slip the clutch. If I just let out the clutch at and give it throttle at lower revs it would die.

And sometimes it would simply die without warning and wouldn't restart. I could crank away, it might start after a few hours, or the next day, or might not until the new coil was installed.

So it was an intermittent problem, but with sort of a pattern to it.

Diagnosis was complicated by other problems cropping up, as mentioned in the linked thread. Vacuum leak, fuel pump, wire to the speed sensor, etc. But those got sorted, and the engine kept doing this “I’ll drive fine and then I’ll die just to make your day hell ha ha” thing.

I’m not much of a mechanic, certainly not a diagnostic talent. It was super frustrating, and led to the van only being used for short but nerve-wracking local drives, and then not getting used much for the past year. Well, the pandemic had a part in that too.
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1988 Westy, Bostig v2.0

[?Waldo?]

It seems to me that you should just update your prior thread rather than starting a new one.

Regardless you should mention that it is a Bostig in the title.

[jyl]

I only live a couple miles from work, and we have lots of cars between wife, kids and me. So it was easy to let the van sit and ignore it. Finally the wife and kids all went out of state and my other car has been in the shop for months, plus it is getting hot in Portland so I didn't want to ride my bike to work.

The van has been sitting in my parking space at work. The battery is dead. I replace the battery, find yet another vacuum nipple that has lost its cheap crap cap, wrap that up with electrical tape, start the van and begin driving home. I figure I'll get it home and then absolutely figure this intermittent dying thing out.

A few blocks into the short drive, the engine starts dying on throttle lift. The first couple times I restart it no problem. Then it does it again, and won’t restart.

By now I've learned to take streets where it will be convenient to break down - wide shoulders, plenty of open curb, etc. So I roll, helped by a little hill, to the curb, and pop the hatch. I have a spare coil and tools, of course.

Hey! I notice something new. One of the three wires to the coil connector is now visibly dangling.

The exposed copper strands at the end of the wire are pristine. They don’t look like they were ever clamped or crimped or soldered. There is a little white plastic collar around the wire insulation that holds it in the connector housing. That collar has split and the wire has come out.

Inside the connector I see a metal “tube” that the wire presumably goes into. It is round, not crimped or anything. It is a bit larger in diameter than the wire. The exposed wire end can be inserted and withdrawn freely.

I scrunch up the wire end and *jam* it into the tube, and *push* the plastic collar back into place.

The engine starts right up and I drive home. No dying, no threatening to die, everything runs perfectly.
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1988 Westy, Bostig v2.0

[jyl]

Order a new connector (Dorman, $24). Cut off old connector, splice in new. Van has driven perfectly for three days since then. Knock wood!

Here’s what I think was going on.

The connector attaches on the passenger side of the coil. The harness has very little slack, at least on my v2 install. If the engine moves (torque rotation) in its mounts, the harness and its three wires tug a little on the connector. Sometimes that means the wire momentarily stops touching the “tube” inside the connector.

That might happen at throttle lift off (torque removed) or when reversing (high torque applied). Sometimes vibration or butterfly wings flapping in Brazil cause the wire to stop touching. The OBD sees a “coil” code and replacing the coil “fixes” it, temporarily, simply because the coil connector and its wires get manipulated.

All this is going on inside the connector, from the outside it looks fine. Until the plastic collar finally gives up and the wire falls out. Which it can, because there is no actual mechanical connection of the wire strands to anything.
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1988 Westy, Bostig v2.0

[JudoJeff]

Do I get a prize for saying “ loose wire” from the get-go?

If all you have on the input manifold nipples are those rubber caps I suggest doing it better. RTV, etc, then the caps. I mix up bondo and plug them but good!

Glad you found it!
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1989 Vanagon GL Westfalia Camper, Burned up on 7/31/16.
1987 Vanagon GL Westfalia Camper, Bostig & Rebuilt, sold
1986 Vanagon GL Westfalia Camper, Bostig Sold May 10, 2021
1999 Ford GTRV Westfalia camper (30% bigger Westy layout)

[jyl]

[Vsyevolod]

Thanks to this thread, I was able to find an issue (intermittent sputtering/stopping) that has been plaguing me for the past 7 months. Error code came up as P0503 Vehicle Speed Sensor. It was actually the middle wire to the coil!

Thanks all for the write ups and sleuthing that goes on here all the time.

I ended up replacing spark plugs, coil, and speed sensor, eventually finding that loose wire that came from the wire harness straight from Bostig, but took 12 years to start causing problems...

Does anyone have a suggestion for how to get this wire back in place and secure?

Stephen