intermittent no start - (was rapid turning over once)

[atomatom]

so, today i did a dump run in the van. all went well in the dumping part, stuff begone. however, when i went to leave, with encroaching seagulls, van did not spring back into life.

what happened instead was a rather strange rapid turning over. as if there was no compression. not a slow laboured churn, but a rapid, bip bip bip.

seagulls encroached. a staff member mentioned 'this happens regularly'. and i cried, 'this van is not ready for the dump'.

after 10 minutes of personal contemplation and a few tries, the van caught, and i drove away. seagulls were more interested in whatever muck was on the floor than me or the van.

but i'm now wondering what the heck that was all about.

i did change the oil a few days ago. checked level, around 1/2 full as per. maybe i have a stuck valve? i guess i'll do a compression test. van drove me home, some highway bits at 100kmh, reasonable power.

1.9wbx, as in my sig.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[harvgwen]

Was it just the starter spinning quickly, and not the engine at all? If so perhaps a new starter?
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1986 Westfalia Vanagon, 2.2 Subaru
Okanagan Valley, British Columbia

[atomatom]

[Abscate]

I didn’t think it happened with a Boxer engines but if you flood an engine you can lose compression from loss of ring sealing. See Thanksgiving syndrome or lawnmower syndrome ( bmws, Volvo, VAG water cooled products)

I thought it was a legend until it happened to me in an E83
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[atomatom]

https://www.brickboard.com/AWD/volvo/1381779/S70/easy_fix_lawn_mower_syndrome.html

plausible i suppose, although i drove it for 15-20 minutes on the highway before arriving at the dump, but perhaps my injectors are leaking. engine was certainly hot when shut down.

i'll check injectors and compression on the weekend. maybe something is still wrong and gives some clues. or maybe it was just dump gremlins.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[hardway]

I have seen dozens of engines lose compression. They used to say that they were "washed down". Observing this compression loss has caused automotive engine theorists to modify their theory of how compression rings work. The current theory is that the rings must float freely in the ring land. On the compression stroke the piston moves up and the ring due to inertia and the air pressure above the ring is forced to the bottom of the land. The increased gas pressure then gets between the ring and piston and forces the ring outward against the cylinder wall.

If for whatever reason the gas pressure does not force the ring outwards then the gas pressure can push the ring in towards the piston and gas can escape the combustion chamber between the ring and cylinder wall.

Engine oil helps the initial sealing of the ring. The theory is that excess fuel dilutes the oil and allows the gas to bypass the ring and not push it outwards. Once the engine has been cranked and fuel delivered without the ring sealing it gets worse. The engine is flooded.

Newer engine types with low tension rings are more likely to have this happen. I have only seen this happen on an engine that was being started when cold. But that does not mean that it can only happen on a cold start. Overfueling could exacerbate this problem.

As I said I have seen this many times. To get the engine to start I have induced vacuum leaks, shut off fuel delivery or held the throttle open. Holding the throttle open is the traditional method of clearing a flood. That is why the software engineers use it as a "clear flood " command.

In extreme cases I clean and heat the spark plugs with a propane torch and put oil in through the spark plug hole to seal the rings.

[harvgwen]

Doesn’t it seem odd that this has never happened before, but suddenly, one time it happened presumably on several cylinders at the same time? (It seems for the engine to rotate quickly, most or all of the cylinders would have lost compression). I’m still suspicious that the starter never actually engaged the engine. I’m looking forward to finding out the eventual outcome.
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1986 Westfalia Vanagon, 2.2 Subaru
Okanagan Valley, British Columbia

[djkeev]

There are ignition parts that fail when hot.

Coil is #1
Hall pickup is right behind it.
I've experienced both.
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Stop Dead Photo Links how to post photos

Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[atomatom]

thanks folks.

some more clues; had a 99% successful road trip this summer in +30C (100F+) temps. heat soaked engine acted up after waiting at a construction stop sign leaving princeton, bc. the symptom there was a loss of power - maybe the same as this time? it was very intermittent, as if running out of fuel, but van kept on going, just scared the whole family. when i got home, i swapped in a spare coil. intermittent problem gone - but who knows. maybe this is the same thing.

you may well be right djkeev, that i still have more dying electronics to replace and it wasn't the coil after all. i have a complete spare engine, so maybe i'll look at swapping the hall sensor - not sure that is so easy - i will go check your saga for ideas. https://www.thesamba.com/vw/forum/viewtopic.php?p=10088796#10088796

...

however, despite all of the possible electrical woes above, it really felt like the engine was spinning awfully quickly during this extended dump stop - rather than just not firing. i'm going to check timing, valves, fuel injectors, and so on this weekend.

harvgwen - i agree, odd. however, even if it was just one cylinder, that would reduce the effort by 1/4 - would not need to be all.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[atomatom]

this is still plaguing me. van starts fine when cold. when hot, sometimes starts, sometimes not.

i just replaced the o2 sensor today, thinking maybe it was fouled from my over filling oil. i think it probably was, but i think this was just a cause of running rough rather than no start.

while testing today, i drove to get the van warmed up, then stopped on a hill. tried to start, failed. bump start, no problem. and the idle is fine after bumping! i did this three times in a row with a few minutes apart - same situation.

i bought a cheap-ish new coil replacement from rockauto. however, i have not installed it. i'm not convinced it is the coil either (i already swapped a used one i had), but i might try that next. i don't have a new hall sensor, but i could try looking at that next. however - given the van runs fine after a bump, would this really make a difference?

is there anything else i can do to make it right from my oil overfilling - or maybe that was a coincidence to these woes.

van smells like fuel when it won't start, so i don't think it is the pump. that leaves air or spark, right? should i pull the air box off and see if there is oil in the intakes or something?

i'm stumped and annoyed because i can't really use my van like this. i live on an island and there is no greater sin than being a stalled car on the ferry.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[atomatom]

also, starter motor is spinning engine, not weak, etc
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[atomatom]

[atomatom]

a few more test drives and things seem much better.

as part of the coil replacement, i put new spark plug wires in. i guess the last set was 10 years old. i have a new rotor cap but didn't put that on yet.

no sign of the no-start symptom yet. so, maybe it was the coil dying. time will tell.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[E1]

I can’t speak to the “why” details, but this sounds like a solenoid/Bendix issue… often caused or simulated by poor cold cranking amps on the battery.

Typically, the fast crank is because the flywheel’s not being engaged to spin properly, from either thing above.

Go to a parts store and have a load test done on the battery, if only to discount that and know it’s in spec or within maybe 10% of it. It’s not a voltage question of the battery, but one of the battery’s labeled CCA (cold cranking amps) not being met (likely by a significant amount).

By your description, I seriously doubt it’s a major engine concern.
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If ever twice as rich, we’re gettin’ a double-wide
’84 “Westfailure”/2.1 Digijet/5.43 Ring & Pinion/Peloquin/D-rated BFG KO2s

AI has spoken to further illiteracy, to steal, to cheat, and to replace humans
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[Wildthings]

[Vanagon Nut]

[atomatom]

E1 - i did suspect the starter, but aside from my first incident, it seems like it is actually turning the engine over. i've been too chicken to turn the ignition with clutch/gears engaged in case it breaks the starter teeth. however, i have pulled the engine lid off and it sounds like it is turning over. the original situation in the dump was strange and i was kind of panicking so i didn't pull the lid off then. i just sat and tried again after a few minutes.

wildthings - thanks, and yes, probably better to tighten up the existing connector. i found that it actually sits better on the coil if i placed it on the other tab (the top connectors on the coil, my van only uses one of them; the plastic connector has slots for two, but one is unused).

(not my coil, but this is how the connector (green wire) is now attached and it seems way more snug, which is counterintuitive)

neil; i seldom throw anything out, but i really should! i will try a multimeter test and chuck them if they are obviously bad. i measured coil resistance but not the wires. nothing was conclusive there, but the new coil was about $60 and both the used ones i have on hand were around 40 years old. (of course, i'll keep the old ones! but maybe write BAD? on them )


to recap:

* had an intermittent ignition problem, since the summer, but it was very intermittent.
* replaced coil with other used part (unknown quality)
* overfilled the oil, which i think fouled the o2 sensor
* drained 500ml or so of oil
* no start symptom remained, with van starting after sitting a while. seemed random as to when this happened, sometimes it was fine.
* replaced o2 sensor, thinking it had been fouled with oil (i can post a pic, but not sure if it is obvious)
* replaced coil with new one and spark plug wires. i heard you are supposed to do both as a bad coil can damage the wires.
* limited testing so far, but seems to run smoother in any case.


so, like most van problems, there was a bunch of things wrong, vanagon comorbidity, but hopefully addressing each of these in turn has routed out the gremlins, for now.
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84 Vanagon Westy, 1.9L, California raised but defected to Canada.

[Vanagon Nut]

I *think* the second open spot on white connector to coil is for a wire to tach (?). If so, and no tach installed.....

If one wanted redundancy, install another "locking" terminal in white housing, connect that to the single green wire? A bit of a "fussy" idea though.

Rhetorical thought: does either nut holding male spade connectors to coil ever come loose?

Neil.
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1981 Westy DIY 15º ABA
(VW Gas I4)

1988 Westy DIY 50º ABA

VE7TBN

[Wildthings]

With that heavy of a plastic insulator around the wire terminal, it would be hard to get to the female spade to pinch it a bit. The plastic is not all that hard to remove from the terminal. I typically just use something like a jewelers screw driver to disengage the tab, but you can buy a set of special tools for this purpose, maybe Harbor Freight has a set??? They can surely be had easily enough on line.

[E1]