Now, it won't start at all

Vancouver Van · Post by **Vancouver Van** » Fri Dec 17, 2004 5:35 pm

So - have been picking through a seeming glow plug problem - hard smoky cold starts, but lovely fast smokeless warm-engine starts.

I've been using it as a daily driver, anyway - trying to track it's behavior in the wild.

The last couple cold mornings, it started oddly - it didn't fire at first, but I just kept cranking. This, after three cycles on the glow-plugs (per the LED, and assuming something actually happens at the motor), and with the cold-start knob pulled out.

Anyway, it would crank and crank, then gradually begin to fire, but without actually seeming to be ready to take off. I just kept cranking until it sounded likely to keep running, then quit cranking, and it did. Smoking like everything, but running. It'd substantially reduce smoking within a block, be barely visible under hard acceleration after a half-mile, and when warmed up fully, there was no visible smoke.

Then, it would start very quickly after short stops - firing within 3-4 seconds, and idling smoothing.

This morning, it wouldn't fire at all. It just cranks and cranks. Seems to crank normally - not too easy, not too hard, no odd noises, just spinning and spinning. It seems not to fire at all. It's as though someone disconnected my coil wire.

**
Under previous posts and via an e-mail, there was some question there might be a failed check valve in the system. If so, it's not in the engine bay. Tank's up under and a bit behind the front seats.

So...given it never had spark, it must not be getting fuel. The injector pump is 'new' to this vehicle, but seemed to work fine and it ran much better than with the old leaking one. There's no sign of leakage....

hoyt · Post by **hoyt** » Fri Dec 17, 2004 9:42 pm

I don't think there is a check valve in the diesel fuel system. I just
look in the Bentley and did not see a check valve in the fuel system.

What I would do is crack open one of the injector lines and see if fuel
comes out when you crank the motor. If it does then you got fuel
to the motor. Have you ever had a compression test done on
the motor?? Low compression makes for harder starting in cold
weather.

srivett · Post by **srivett** » Fri Dec 17, 2004 11:52 pm

It could be the solenoid wire or IP solenoid. Find an assistant walking past your place and have them turn the key off and on while you listen to the pump. Also try powering your old IP to see if it makes a noise at all...I believe I read that they do.

Good luck, Steve

Vancouver Van · Post by **Vancouver Van** » Sat Dec 18, 2004 5:51 pm

Interim test results....

no fuel coming from the FROM the injector pump - I tested one, and it was dry as a bone.

no fuel coming INTO the injector pump - I pulled the hose that comes from the fuel filter, and even after 15 seconds of cranking, it hadn't dripped yet. Didn't drip on dissassembly, either.

I assumed "IP solenoid" referred to the injection pump solenoid - my old pump is in pieces in a plastic bag; that solenoid has a spring-loaded tip to it; with the body of the valve grounded, the tip pulled into the body when positive juice was applied to the valve's electrical connection-end.

So, on the van - I applied positive juice to the valve's electrical end, with a finger at the base to feel the valve move. I didn't - but that's inconclusive. I couldn't really feel the other one, either. But the glow plug relay clicked nice and loud. I'll test again via the ignition switch when my assistent arrives....but...

it seems to be it's just not getting fuel. I lent my Bentley to the PO, and he changed jobs and disappeared...I don't even know if their is a conventional fuel pump in the system....if not, it all functions on suction from the injection pump. That may be, be seems prone to interruption.

Off to busdepot.com and such, to see a fuel pump is listed, then to Powell's City of Books to study the Bentley.......

thanks!

hoyt · Post by **hoyt** » Sat Dec 18, 2004 6:00 pm

There is not a fuel pump on a Vanagon diesel, just the vane pump
in the IP.

The fuel line between the tank to the fuel filter could be pluged.
I owuld start there and see what you find.

Vancouver Van · Post by **Vancouver Van** » Sat Dec 18, 2004 6:12 pm

Yep - I just read up on it at http://www.cs.rochester.edu/u/jag/vw/. They've an "exploded" view of a pump there, and a good technical article on how the pump functions.

I'm guessing the most likely plug is the fuel filter itself - and am inclined to replace that, reprime the pump, and see if it fires and runs.

I've put perhaps 3000 miles on this filter, so it shouldn't be plugged...but then, neither should the rest of it.

Oh well - it's a lovely day for lying in the street!

Vancouver Van · Post by **Vancouver Van** » Tue Dec 21, 2004 3:00 pm

I thought to test more thoroughly before crawling under the van and tracing out fuel lines....

I disconnected each of the four lines running from the pump to the injectors; I pulled them one-by-one, at the back of the pump. I wiped each clean, refolded my rag, positioned said rag, and cranked the engine for ten seconds - by counting one, one-thousand. Each time, the rag then bore a Diesel stain a bit larger than a silver dollar.

Then I removed the brass fitting where the line from the filter enters the pump. You can see into a chamber there, just a bit; it was full of Diesel. I left the line off and cranked the motor for a ten-count. That chamber emptied. I refilled it and put the fitting back on.

I also drained a bit of fuel off the bottom of the filter, before doing all this.

The van, in all that cranking, never seemed inclined to fire.

But I think it's getting fuel - I don't know if that dollar-sized stain is enough, though. I rather expected it to just splurt out and make a mess all over the engine bay. I suspect, from comments here before, that getting too little fuel would have caused the smoky cold starts. If the dollar stain is way too small, perhaps the constriction has simply worsened to the point it won't start at all.

*
Having found an ammeter in a box of stuff I should've thrown away years ago, I'm going to go fiddle with the glow plug system - see what kind of amps it's using.....

Vancouver Van · Post by **Vancouver Van** » Tue Dec 21, 2004 3:54 pm

I did two quick electrical tests -

first, I connected an old dash-mount style ammeter into the glow plug circuit. Working from memories of high-school shop (class of 1983), I opened the circuit by removing the lead at the first (furthest away from the timing belt) glow plug, then ran a pair of jump wires up to the front, where I connected them to the ammeter. I then turned the ignition key; I got my usual LED, which previously was tested and shown to match voltage cycling....but I got NOTHING on the ammeter.

Later, I'll test that ammeter.

*
Then, because I'd been charging my van battery off my Accord, and had the cables handy, I hooked up my jumper cables. I put the negative leads on the block and the negative terminal of the battery. The positive lead I ran from the positive battery terminal to the first glow plug. Nothing. No spark as I moved in on the target, no warmth after holding it there for a count of 12 seconds or so.

*
Are these tests reasonable? I'd expect to generate heat, jumping like that.

Vancouver Van · Post by **Vancouver Van** » Tue Dec 21, 2004 9:01 pm

Alrighty - now that I've answered myself three times....

I tested my old ammeter; it seems to work just fine. Not the most accurate gage on Earth, but I could tell when a little 4A motor was running, as well as a bigger motor. I'd say it works. And it said my glow plugs were drawing zero amps.

And when jumped, they don't get warm.

Here's my hunch: when I had smoky starts, I had only 2-3 plugs heating. When I had to crank long and hard to get it started, I had 1-2. Now that it doesn't start at all, I'd say I have none.

Is there another possible explanation?

I think tomorrow I shall remove my injectors, look in to see if the plugs are turning red, and if not - replace them all.

hoyt · Post by **hoyt** » Tue Dec 21, 2004 9:18 pm

Have you check the glow plug fuseable link?? It is in a plastic
box next to the glow plug relay.

Vancouver Van · Post by **Vancouver Van** » Tue Dec 21, 2004 9:56 pm

Yes - though...it doesn't look like fusible links I've encountered before.

Basically, it's a metal strip mounted on two screws. It passes a visual inspection - it's intact and not corroded and the screws are tight - and it delivers voltage. On my van, it's mounted to the left of the relay.

If it was bad, would I still be getting 12V at the first glow plug? I'd have guessed not...but electicity I do by feel, as the principles seem to escape me, usually.

hoyt · Post by **hoyt** » Wed Dec 22, 2004 12:40 am

If the link was bad then you would not get 12V at the glow plugs.
I would take a look at this at http://www.4crawler.com/Diesel/CheapTri ... lugs.shtml .
This page is about a VW truck, but the glow plug system is the same.