MF 1235 Smokes Bad when Startting

[gflitter]

My MF 1235 with 450 hours will not start without using the glow plugs and it just pours out black smoke when I try to start without the glow plugs. It runs well and does not smoke much at all once it is started. I have new air filters installed, so that is not it, and I understand that the black smoke is unburned fuel, but I do not understand why it doesn't smoke much once started. Can anyone tell me why it does this? /forums/images/graemlins/confused.gif

 

[AntrimMan]

I'm sorry no one more suitable than myself has offered you some help. I know nothing about a lot of things but I do like to see myself talk, so take this with caution.

Learn about the following topics if you need to...

1) Atomization (spray pattern), learn what affects it and how the pump and injectors work together in unison.

2) Injector leakdown.

3) Cylinder compression.

If, as you mention, the engine runs fine once started, I would imagine there is no air intake restriction or lack of compression and the problem is related to the timing or quantity of fuel delivered to the compressed air. The ratio is incorrect. Leaky injectors will cause fuel to accumulate when the engine is not running on a gas engine, the engine will start fine when dead cold but will appear to be flooded and will be hard starting if restarted after a short, incomplete, cooldown. The gasoline will evaporate overnight allowing easy cold starts, the diesel will to a much lesser degree. The fuel volume leaked is related to availability, time, and the injector leak rate.
Once running, the time period for the leak to accumulate is greatly shortened and the results much less noticeable.

"And that, ladies and gentlemen, is your basic turbine engine"---Cliff Clavin.

This advice is probably worth what you paid for it.
Sorry I can't be of more help.

All the best,
Martin

 

[Jeff396]

I have a guess from my limited knowledge of diesels. The purpose of the glowplugs is to preheat the cylinders to help initiate the burn of the fuel. I would imagine that when the cylinders are cold without using the glow plugs the fuel is not completely burned and the black smoke is the excess fuel coming out of the exhaust. I would also think that the fact that the diesel fuel is not near as volatile as gas also contributes to the situation. Once the engine starts and the cylinders heat up a more efficient and complete burn takes place and the black smoke is eliminated. I'm not sure why you would want to start your tractor without using the glow plugs......I use mine everytime I start either my truck or tractor. I have heard many say it is not necessary to use the glow plugs on a restart when everything is still up to operating temp though.......but I still do.

Jeff

 

[SteveInMD]

</font><font color="blue" class="small">( My MF 1235 with 450 hours will not start without using the glow plugs and it just pours out black smoke when I try to start without the glow plugs..... )</font>

Actually unburned fuel usually gives you white smoke from a diesel. If I start my tractor or my diesel pickup without using the glow plugs I get white smoke. While running, black smoke us usually from too little air.

You said you get black smoke when you start without using the glow plugs. It probably just builds up a lot of fuel in the cylinders before it fires and when it does it has more fuel than air. Why would you start it without using the glow plugs? I'm not surprised it smokes when you do this.

 

[JerryG]

Use the glow plugs, that's what they are there for. You should have very little smoke upon start up by doing that other than maybe an initial puff.

 

[AntrimMan]

Here is some info I just stumbled upon. I don't have the background to critique it's accuracy or completeness.
I figure if it's free to view on the web then it's ok to post the link here. I have no connection to the company.
diesel smoke


If the link doesn't work.... http://www.bowerspower.com/Diesel_Troubleshooting.htm

Hope this helps,
Martin