Thread: series glow plugs

Originally Posted by Gromit68

1. smoke swirls off the negative earth coiled-metal thingee mounted on the bulkhead. Current is flowing!

Smoke?
I'm no expert, but should the be smoke?

Series glow plugs are "series" wired, so if current is being drawn they are working fine. Must be a fuel problem.

That said, I used to do the following on cold mornings:
1 Crank over 1 or 2 turns
2 Press glow plugs for 10-30 secs without cranking
3 Crank immediately after releasing glowplug switch (or start just befor releasing).

Spraying some fuel in the cylinders first seemed to help, as did cranking without glow plugs (faster cranking).

Originally Posted by Gromit68

You guys must think my truck is a dog of a thing! It's actually a nice little LR when it's running right.

Since my water and air-in-diesel problem, Gromit has become difficult to start when c-cc-cccold.
Starts easy when warm though!

Could I have a little bit of residual air in the system? It ran beautifully along the M5 from Campbelltown to the city this evening.

Here's what happens when I do a cold start:
1. smoke swirls off the negative earth coiled-metal thingee mounted on the bulkhead. Current is flowing!
2. When I glow and start together, the starter motor is much slower. Current is going somewhere.
3. After a 20sec glow, I turn it over. White smoke putters out the exhaust, followed by grey smoke as it catches and eventually black smoke as it roars into life.

If it is a glow plug problem, are they easy to change and where can I get some? Are they exxy?

Alastair

Try this mob on eBay, "poppysbargains" I bought a set of glow plugs for a Toyota 4Runner for $36 a year or so ago and there still working good, check out this item #on ebay 220139735682 you only need a couple of glow plugs not working to cause the problems you're having,
Regards Frank.

Alistair,

I don't think it's a glow-plug issue. Stuffed glow-plug (1) would mean all of them are dead and starting would be near to impossible as they are in series (no pun intended). The fact that you have current flowing through the resistor means they should be OK.

It sounds like you might have air in the system (still) or your timing is stuffed. Does the engine start when hot? Normally it should not need glow-plugs when hot. Up in FNQ with high ambient temp I almost never needed to have a minute of silence for Mr Diesel.

Do a search on the net for diesel smoke colour and cause. Might give you an idea what to look for:

http://www.freeautoadvice.com/diesel/smoke.html


-- Irek

uurmmmm....

1. you have a, bad connections along the lines causing voltage drop stopping the glow plugs from working correctly. to check this out try the following have someone key the glow plugs while you measure the voltage across each glow plug you should see about a 3v drop on each plug if you have 12v on the battery (check the battery voltage while the plugs are turnd on first then devide that # by 4 for each plugs representive voltage) or disconnect the wires from the glowplugs (pay close attention to how the wires go and the insulation posts are assembled) and check each plug for resistance you should get between 2-4 ohms.

2. your starter motor might be a bit sad and not spinning the crank fast enough for the combustion chamber temp to rise to the ignition point fast enough. to check this out the only thing you can really do is a current draw test on the starter motor or pull out and clean up the starter. (this is of course assuming the battery is ok) another point to check is the voltage along the circut of the starter motor 99% of your voltage drop when cranking should be across the startermotor itself, from memory for every volt that goes missing outside of the starter motor you are robbing the starter of aproximately half its power (ie 11v is nominal at 10v you have half at 9v you have 1/4 at 8v you have 1/8 at 7v you have 1/16 at 6v you have 1/32)

3. you might have a fuel problem in that the injectors are worn and instead of injecting a nice mist they are "jetting" the fuel in a stream which is much harder to ignight.to check this order in a new set of injector seals and when they arrive one at a time remove each injector and mount it upside down on its injector line, crank the engine over and with gloves on hold a white piece of cardboard in front of the injector nozzle about 4 inches away you should wind up with a nice wide wet spot on the card, if you get a small spot that looks like it was trying to shoot through the card then your nozzles are fubar and need to be replaced ($35 each for the replacement nozzle kit +fitting and testing)

and finally

4. you might have compression loss, do a cold compression test then a hot compression test and see whats what. The bush method is with the crank handle, insert and turn the crank through 2 revolutions every 180 degrees there will be a compression stroke, if one feels easier to crank through than the other then you have a compression loss on one cylinder. If the whole test (once done with the motor stone cold another with it at operating temp) is easier than the other then you have a worn engine that is getting close to wanting new rings as a bare minimum.


hope that helps

Dave has covered just about everything except another possibility is a short to earth part way along the chain of glow plugs, so one or more are not working. (On one occasion my speedo cable shorted against number three plug with similar effects !) But my guess is that either the battery, connections or starter are bad, as there should be no noticeable difference in cranking with and without glow plugs, as the glow plug current, while quite high by, say, lighting standards, is pretty small compared to the starter current.

In Sydney's climate these engines should start readily even without glow plugs.

John

nahh I snuck that in with the voltage drop on the plugs thing.... I just didnt explain it..

if you had a voltage drop to earth youd have voltage on a couple of plugs but then youd have none on the ones after the short......

SNEAKY.....

Originally Posted by Blknight.aus

nahh I snuck that in with the voltage drop on the plugs thing.... I just didnt explain it..

if you had a voltage drop to earth youd have voltage on a couple of plugs but then youd have none on the ones after the short......

SNEAKY.....

And a short and merry life for the ones with voltage!

John