Starting problems for a NH 1715

mikelh · Apr 2, 2015

This may be a bit lengthy, so please bare with me. My 97 NH 1715 is having starting problems. About two years ago I went out to start it at an idle and it would not start. It seemed to be laboring because of the battery so I replaced the battery. It still would not start, just turning over and no fire. Out of desperation I pulled out the kill switch and tryed it and it attempted to start and then died. Just a note here, I had replaced the glow plugs, and put in new lines from the fuel tank to the glass fuel filter as well as replaced the filter. So anyway I tryed to start it again and it labored but finally started. Felt like the battery was running down, but it finally started. Another note here, this little tractor started first time every time at an idle. I used it and it ran like a top and then I parked it. The next time I went to start it the tractor would not start. At this time I took it to the NH dealer for examination. They checked the glow plugs which were fine. They checked the injectors which had some low pressures, so we replaced them. The also took the injector pump apart and put new seals in it and checked the operating pressures and they were fine. I went over to check out their work, and they informed me that it would now start everytime, but I would have to start it at full throttle and then slowly back it off as it warmed up. This seemed odd to me, but their explanation was that they felt the timing system was compromised. I have used the little tractor now for two years, in winter and summer and as I mentioned it runs fine and starts if I use a full throttle to start it. It is always plugged in when cold as I installed a block heater on it. Here's the thing, IF I do not get it started on the first try it will act like it is flooded(gas engine) and I have to wait for about a 1/2 hour and attempt it again and it starts fine. I know that you cannot flood a diesel engine, but that is what it acts like. Once again when it gets warmed up it is fine a runs like a million bucks. It only has about 800 hours on it, and I am puzzled by this. If the engine is warmed up or it is warmer out I can start it at an idle very easily. The warmer it is the better is starts. Well there you have it, I await any and all theories.

mikelh · Apr 4, 2015

Hey all out there in little big tractor land. I really need some help brain storming this problem. Any and all suggestions would be appreciated.

mostly_gas · Apr 4, 2015

Do you get any smoke during cranking when engine is not starting? Typically no smoke indicates no fuel, white indicates fuel present but not combusting well. Do you have a timer on the glow plugs or you just turn the key left until the indicator glows?

skyhook · Apr 5, 2015

Could be air intrusion, check all your fuel lines, even the return lines or....
could also be lack of turning power, next time you do a 'cold' start, have booster cables on the battery,
see if it starts better when boosted.

90cummins · Apr 5, 2015

Just because they replaced the glow plugs does not mean they are working properly.
Check the current or resistance thru the glow plugs to verify they are in working order.
Use a volt meter to check for a full 12 volts at each glow plugs when you heat it, also use the volt meter to see how long they heat on the timer.
These tractors start very good if the cranking speed is up there. My 1720 starts at idle fine.
Another thing you can do is check the voltage drop of both the battery cables, again using a volt meter.
Cranking speed is very important.
For lack of a volt meter you can check the battery cable connections for excessive resistance by cranking it for a while the touching the battery terminal and all other connections between the battery and starter and battery and ground point on the block.
If any connection is warm there is a problem that needs to be corrected.
It may be as simple as removing and cleaning the connections.
90cummins

mikelh · Apr 6, 2015

There is white smoke, which I will check out the low fuel problem. It blows out black smoke when it starts and will surge until it warms up. The surging goes away faster when it is warmer and as it warms up.

mikelh · Apr 6, 2015

Thank you very much for the thoughts. I did put a new battery in when I initially had the starting problems. That did not solve it, but I will check it again. Appreciate it very much.

mikelh · Apr 6, 2015

Thanks very much, and I will check this all out.

mikelh · Apr 6, 2015

The key on mine turns to the left and I hold it to the count of 60. There is an indicator on the dash with a glow coil in it. I can see the coil glow brighter as I hold the key. When my problems first started, I would hold the glow the key on and the coil would glow bright very quick. The tractor seemed to labor to start, which is when I replaced the glow plugs. Then the tractor started fine, but the coil took longer to glow. Everything seemed fine, and I was patting myself on the back for saving some dough. Then I started having the start problems at the idle. Changed out the fuel lines and filter, still nothing, then the battery and I got it started with a lot effort. THat is when I took it to the NH dealer. The installed a new injector rack at considerable cost and checked out the glow plugs for resistance and rebuilt the injector pump. That is when they told me it was probably the governor in the front of the engine.

skyhook · Apr 7, 2015

Sixty seconds on the glow plugs seems a bit long for me, that will take considerable "juice" from a battery.
Depending on the size of your battery, I would try doing a start with another vehicle "boosting" your machine. The faster she turns over, the better.
I have had similar problems on mine, when the temps were cold outside ( I have a volt meter connected on my machine, always, to know if its charging well or not) I would read about 12.3 volts on my battery,
I would then turn the glow plugs (thermistor in my case) on for about 20 seconds, the battery voltage would drop to about 10 volts, causing a slow turn-over. I then installed a "smart trickle charger", it stays on the battery always and its plugged in when the machine is not in use.
Now when i turn the key on, the voltage reads 14.3 volts and when I start the glow plugs, it goes down to 12.2 volts, she turns over faster and starts easier.
It made a huge difference in staring in cold weather.
Try it.