1520 Engine hard start and smoking

[bbomer]

Hi, I'm a newb so any help would be appreciated.

I've owned my '89 1520 for 4 years and never really had any issues. Recently it started running rough right after I started it, but eventually it would even out (once the engine was hot). By rough I mean that it felt like it was missing and there were abnormal puffs of smoke coming out the muffler, usually only noticeable at low RPM. Eventually it got so that sometimes I'd have to try 2 or 3 times to get it started, which was concerning since it always started immediately before.

I figured it might be an injector problem (they are 20 years old after all), so I pulled one and it looked pretty filthy (could be normal for a diesel as i don't have much experience). I replaced them all with NH parts from my dealer. Unfortunately now the problem is worse than before. The tractor is harder to start and I see puffs of smoke and drops in RPM even at high throttle.

Is there some other adjustment I need to make after replacing injectors?
I'm hoping I didn't make an even bigger mess of things...

 

[Egon]

Have you checked out the fuel system for water and changed the filters ?

 

[RickB]

You probably have a bad glowplug, or other issue within that circuit.

 

[bbomer]

Have you checked out the fuel system for water and changed the filters ?

I changed all the filters (including fuel) at the same time as the injectors. I suppose I could drain the tank and lines and put in new diesel. What else should I do to check for water?

You probably have a bad glowplug, or other issue within that circuit.

I thought that too, but I also get puffs of smoke (although much less frequent) every time I go to high RPM regardless of engine temp.

 

[Egon]

What else should I do to check for water?


Just check at the filter canister bottom.

 

[jinman]

I thought that too, but I also get puffs of smoke (although much less frequent) every time I go to high RPM regardless of engine temp.

I suspect that you may have "soaked" your exhaust/muffler with raw fuel and it may take some time to clear out. Puffs of smoke on a diesel are not uncommon when increasing engine rpm, especially under load. Perhaps you are just a bit more sensitive to seeing smoke now that you are trying to trace down a problem. As RickB said, hard starts and rough running while the engine is cool that go away when the engine warms are most likely related to glowplug performance. When you try to start and raw fuel gets pumped into the exhaust, things look a lot worse than they are once your engine starts.

 

[bbomer]

Just check at the filter canister bottom.

Haha, guess I'm making this harder than it needs to be. When I changed the fuel filter, I emptied the bowl. I didn't check before I emptied it. I will check it again tonight to see if there is any that may have accumulated since I changed the filter.

Perhaps you are just a bit more sensitive to seeing smoke now that you are trying to trace down a problem.

I can't deny that.


I will replace the glowplug and see what effect that has.

 

[RickB]

I will replace the glowplug and see what effect that has.

You are going to get real tired of buying and replacing parts if you don't slow down and do some troubleshooting. Are the glowplugs getting power when activated? If so, remove the buss bar from the glowplugs and test each one individually with a VOM. A good glowplug should read a little over 1 ohm. Alternatively, a good glowplug (or one with a dead short that would instantly blow your fusible link) will light a test lamp when power is supplied to the alligator clamp of the test lamp and the probe is applied to the glowplug power terminal. I prefer the VOM test myself, but not everybody has a VOM and some that do don't know how to use it.

BTW, there are three glow plugs.

 

[bbomer]

@RickB

I have the repair manual, I will follow the instructions on testing the plugs (all three!) from there. I have also have a meter and know how to use it. :thumbsup:

After considering the entire status of my tractor I'm starting to think something more severe may be the issue, or at least I have multiple issues to be addressed. Other symptoms are: gurgling or boiling noise coming from underneath after running at full throttle for some time (clearly some radiator or coolant problem) and maybe some excessive blowby (I can see exhaust from the black tube coming out the bottom). I'm not sure how much exhaust should be coming out that tube, but I never noticed it before.

 

[Hooked_on_HP]

Have you ever checked your valve adjustment. This can also cause the symptoms you are describing.
Bill