G1800 (D662 engine) Glow Plug troubleshooting

[jas67]

I tried to start my G1800 today for the first time since last fall.

I just bought it last spring, and noticed as the weather got cooler, it took a long time (2-3 minutes) for the glow plugs to warm up enough to start.

Well, this morning, 40 degrees, no start. I'm getting a little white smoke, and fuel smell, so I know I have fuel. I even tried the hair dryer into the intake manifold trick to help, but no go.

I had my automotive battery charger connected while trying to start it, and noticed only about a 2-3A additional current draw when activating the glow plugs, vs. just charging current for the battery. Is this enough?

Does anyone here know how much current the glow plugs should draw?

Glow plugs are $25 ea (times 3), so I want to be sure they're the problem before I older them.

Thanks,
Jay

 

[Willl]

The plugs I've played with draw about 5 amps a piece.

Many years ago I made a crude glow plug tester out of a in-dash amp gauge.
(like this one)

Attached 2-3' #12 wires to the term and cut the extra term length off.
Drilled 2 holes in a paint can cap for the wires and glued it to the back to cover the terms.
Stuck a small alligator clip on one end for plug, other end stripped 1/2" and tinned.

Edit; Got a 12V test light ?, that would give you a quick continuity check.

 

[jas67]

Then these are probably shot. I'm seeing a TOTAL of 3A for all three.

I guess I'll try powering them directly, one at a time, and measure the current, to be sure that the problem isn't wiring or a bad ground or something. I have a clamp on DC current probe, so I can use use that to measure the current.

Thanks,
Jay

 

[jas67]

OK, just a followup.

I was looking at the ammeter on the charger as a guide to how much current was required for the glow plugs. The battery was doing most of the work. I'm an electrical engineer -- I should have know better. I put my trusty clamp-on DC current probe on the glow-plug wire, and they collectively draw 25A when on. So, that should be plenty of heat.

My battery charger died during all this, and I don't think the battery is charged enough, because it isn't cranking too fast. So maybe the problem is just too low a charge. I'll get a new charger this week and try again.

This still doesn't answer my question as to why it has been been a b***h to get started when it cold (cooler, below 50 degrees). My B7100HST starts fine even when it is 20 degrees -- and that is with no block heater or anything.

Any ideas on what to check for? I do not know the hours on it, as the hour meter died early in its live (57 hours). I guess low compression could do it. It doesn't seem to be burning (engine) oil, so if the rings were loose, I'd expect blow-by.

Thanks,
Jay

 

[David_Kb7uns]

Have a G2160-60 with the D782 engine and a 40A alternator(the dyanamo would not keep up with the electric Power Steering unit). When it is below 45 outside I get about one shot at doing a good preheat and cranking until the stater begins to slow down and I hope the engine catches, below 35 I need a jumper pack. My opinon is that the batteries in the garden tractors are too small to handle the reserve needed to do the preheat and then crank the engine fast enough to get a start. My unit has less then 100 hours on it and I wonder what I will have to do to put a bigger battery in as it ages and needs more CCA as it is tight between the radiator and steering shaft. Try giving the battery a good charge and maybe try a booster to get it fired up, maybe just weak battery and the glow plugs are ok.

David Kb7uns

 

[jas67]

The battery was brand new last year, so probably just a little low from sitting all winter.

I'm getting a new battery charger tomorrow, so I'll give it a good charge, and then try again.

Thanks,
Jay

 

[kobyp]

if you're gonna let your equipment sit for that long, invest in a battery tender.

just my opinion