Newbie to the Van!

[WAgrower]

Last night I meant to pull the GPs and give them a test, but the air in the line just took too long and I ran out of daylight
It may be a few days before I get some time off but checking plugs and clearing air are top priority.

What fist caused this was putting in the "T" for a vacuum gauge; the fuel just flows into the vacuum line because it goes under the bus... I'm thinking of putting a check valve in does that sound like a bad idea for any reason?

Ok so the check valve wouldn't allow the gauge to reset to 0; should have thought through that one a bit more... Guess I'll run the hose along the coolant lines to keep the fuel from gelling in the cold.

Thanks guys.

[rsxsr]

You can check the glow plugs without removing them electrically. You will need an amp meter to do this test. One of the cheap hold on ones will work. When you turn the key to on, the amps to the glow plug could spike as high as 90 amps, but should settle at 36 amps until the relay shuts off. That is 9 amps per glow plug. If you have 27 amps indicated, one plug is out, 18 amps indicated, two out, 9 amps indicate only one is good, zero amps, all 4 are out assuming you are getting 12 volts to the glow plugs.

[WAgrower]

I am getting 12v at the plugs; last time I checked via resistance and they all showed a little over .6ohm.

Thanks for the amp numbers I'll hook my fluke up and see what the range shows.

One quick question: when the glow plug light in the dash goes out I still meter 12v @ the plugs. When I start it while warm the light doesn't turn on at all (not sure about the plugs).
Does this sound like a relay going?
also this is a silly one but have to ask; do the 7sec plugs stay on for 7 sec and the 20 sec ones stay on for 20 sec? The bently says I should have the slow 20 sec ones but the dash light is only on for about 7 sec and the PO said something about changing out the plugs and relays with a different type...
Do the fast plugs work with a slow engine??

[coke]

The fast plugs draw more like 12 amps per plug. The slow plugs would draw 9 amps per plug.

You can't mix and match fast plugs and slow relays or vice versa. The relay takes a temperature sensor input and determines how fast the plugs stay on. In really cold climates, even fast plugs will keep the light on for extended periods past the "7 seconds".

The light on the dash is no indication whatsoever of voltage at the glow plugs. Its merely a recommendation on whether or not the car should be able to start. Some people prefer to put a 12v led in the dash somewhere that indicates actual power to the glow plugs, so they know when they're actually on, but they will remain on after the light goes out for some time, and on my vehicle they'll remain on for a few seconds after the car is started.

All the temperature sensor does is send a value back to the relay to tell it to come on or not, and for how long to keep the light on the dash on for.

[Fatmobile]

12 volts at the glow plugs sounds too high.

I haven't checked in awhile but I thought, after going through the glow plug relay, the fuse and all the connections it was supposed to be closer to 11 volts,.. but maybe that was with glowplugs and the starter going.

High voltage could mean not enough draw,.. but an ammeter would be way more accurate.

[WAgrower]

Thanks Coke for the explanation of how it all works together! I'm an electrician by trade (who deals with ALOT of DC) so I'm pretty sure I can trouble shoot it with that info, I was just getting a little mystified by how the circuit works- what's sending a signal to where.

12v seems high?... Hmmm I'll see if I can meter it while I crank too- kind of hard in the van...

[coke]

I get like 10.9-11.5 volts on my bus bar.

[WAgrower]

interesting... I do have a rather large battery; in fact it's so large the label with the ratings on it has rubbed off on the battery housing.... So I don't know the Ah but it's a big one; best guess would be about 500 to 550.

Thanks for the input!

[joat]

there is also a wire from the starter solenoid that drops the glow plug relay out when the engine is cranking (smaller load for the battery)

[coke]

So why does the relay have a termainal specifically numbered and labeled "power while cranking"? I read from several sources that the glow plugs stay energized while the starter motor is cranking. I have checked the relay on my 90 (before I sold it) and the relay and bus bar were energized while cranking the engine and didn't turn off till about 4 seconds after the engine was running.

[WAgrower]

Well sure as s*$% 3 out of 4 GP are kaput!

put them to the battery this morning and not even a spark from 3 of them and the 4th only got warm...
Hmmm so I'm hoping they were tired and old before all this tinkering which just pushed them over the edge.

Already have a new set in the mail so those will be swapped out asap.

I guess this could be why I was metering 12v @ the plugs.

I do have a wire going from the starter solenoid to the relay but haven't checked as to weather it cuts the plugs while cranking. I'm almost thinking at this point to put a toggle at the dash for the plugs and by-pass the relay entirely; my relay is looking a little tired too.

So waiting for plugs and whole day off!!

[WAgrower]

New plugs installed, replaced the hard lines and got all the way to having the fuel lines purged of air before the battery died.
As the battery wound down, I didn't hear any sputtering or see any smoke so I'm hoping a fresh charge will remedy all this.

Question; what if any harm is there in leaving the engine flooded. It's been 2 tries of cranking for about a min each time, and a few days between tries. So will the diesel evaporate over time or just sit in the chamber?

[coke]

Are the injector lines loosened while cranking to purge the air from them? Are you sure fuel is even getting into the engine?

[WAgrower]

The lines were cracked @ the injectors and took about 30-45sec of cranking to get spurts. I'm seeing fuel in the clear lines before the pump and seem to have quite a bit of pressure in the line.

One thing that makes this more complicated is my return from the pump goes to a "T" into the line before the pump. Once reason being as a purge loop for the WVO, second being it's a conversion from a gasser so no return line to the tank (I think...).

[Fatmobile]

How can you purge air from the pump, and prime it;
when the return line is connected to the front of the pump?