2.1 Cylinder not firing

[Robw_z]

Hey all,

I let my 2.1 idle for about 20 minutes outside on a hot day to charge up my brothers dead battery. His alternator was bad and he needed to make a distance to a shop.

I set a timer and when I came back outside it wasn't running right. Rad fan was cycling, temp needle indicated hot but not overheating.

It hasn't run right since, and I determined it isn't firing on the upper left cylinder as looking from the back.

It has spark, it has 120 compression. Do fuel injectors just quit? I hit the injector with a hammer a few times, no dice. I swapped the injector wiring connectors on that side, no dice.

I'm aware all signs are pointing to an injector, but do they really just stop working?

-Rob

[Steve M.]

If there is any dirt/debris in the fuel system then yes it can stop spraying if the nozzle gets clogged by the dirt at the right moment. The spray ports are very fine so it doesn't take a lot to clog one that's why clean fuel, fuel tank, clean fuel lines are important.
Are you sure it is not the spark plug not firing at that plug?
Be sure you have new small o-rings for the injectors if you remove them.
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[MarkWard]

Without an automotive stethoscope, a long screw driver will work. Place the tip on the injector and the handle against your ear. You can hear the injector cycling. Listen to an adjacent one to get an idea what a working injector sounds like.

The other option is to pop them out and visually check the spray pattern.

In answer to your question an injector can quit. I’d also caution you against doing what you did for your brother. It’s not a good idea to use your van as a battery charger. Especially one that is flat dead.

[djkeev]

I would also be reluctant to leave my unit idling/running unattended for a period of time.

That is when things are prone to going south and cooling fans don't kick on or some similar calamity.

Dave
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[DanHoug]

another possibility is a cooked coil resultant from extended idling. if the coil is damaged and has a lower output, that missing cylinder COULD be one with a poor plug wire, mixture anomolies requiring hotter spark, etc.

3 things go on at idle that can damage Vanagon coils...
- under deck temps become the hottest with engine and exhaust heat and no air circulation.
- no convective cooling of the coil itself, which gets hot on it's own from current consumption to produce spark.
- the coil dwell time MAY increase at low rpm, i don't know that for sure as that is a programming factor in the Vanagon ECU, but it certainly happens on a traditional points system. the ECU may back off coil 'on time' at low rpm or it may not. dunno, haven't measured it myself.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
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[Phaedrus]

Does it have spark at that cylinder, specifically? Pull the plug and check. Also check for a fouled plug. If you have good spark AT THAT CYL and the plug is good, put eyes on the injector spray. Pull the injectors out of that side so that you can see the tips. Undo the distributor hold down nut. Pull the dizzy up so it disengages from the drive gear. Be careful not to put too much strain on the hall sender connection. With the key "on," spin the rotor and watch the injectors pulse. Is the suspect injector spraying?

Fouled plug or bad injector are the likely culprits.

If it is a bad plug, don't just replace the one and call it a day. Go ahead and do a full tune up. It is time.
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1986 WBX (Tin Top Camper)

[Robw_z]

Injector not spraying anything. Rebuilt one on order.

-Rob

[Phaedrus]

Right on. For good measure, it could be worth doing the same test procedure, only this time use a test light at the injector connector (injector unplugged). With the test light in place (one end touching one wire end, the other the other end) see if the light pulses. This will absolutely isolate the injector as the issue, and not a faulty or corroded connection/wire.

This will become clear via the same test with the new injector in place as well. So, perhaps not worth the trouble if you've already got one ordered.

Cheers,

-Alex
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1986 WBX (Tin Top Camper)

[Robw_z]

It is my understanding that all I injectors fire at the same time. Either way, I swapped wiring with it’s neighbor injector, and no difference. So I’m hoping it’s the injector.

-Rob

[Phaedrus]

They do, you're just isolating what exactly is the fault here. By testing that part of the harness, you're verifying that there's nothing wrong there specifically, like a bad connection. The swap test you performed is just as effective as what I suggested. A new injector should do the trick!

Cheers
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1986 WBX (Tin Top Camper)

[MarkWard]

[Phaedrus]

Right on, good to know
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1986 WBX (Tin Top Camper)

[hans j]

A specific noid light for testing injectors and solenoids is incandescent and pulls about 100 milliamps. You can light a LED with 12v and almost no current, but to test wire integrity, you need a little load on it. I'll have to current ramp a vanagon injector to see what they pull. I could probably do it in the next couple of days.
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