743 Smokes at start up BAD!!!!!

[mlsteele]

I have a 89 model 743 with the Kabota engine. When it is cold I heat the glow plugs for about 15 sec. I turn the switch and it acts like it is slow to take the fuel or is either getting to much. After about 2-3 sec it idles up to normal and smokes bad. It will smoke for about 10 sec and it smells rich too. What is the deal here??? Thanks MS

 

[OldMachinist]

What color smoke? blue(oil),black(incomplete combustion) or white(raw fuel or coolant)
Could be a bad /leaky injector.

 

[Tazza]

What color smoke? blue(oil),black(incomplete combustion) or white(raw fuel or coolant)
Could be a bad /leaky injector.

I glow mime longer than that. If i don't, it will start but run poorly till the missing cylinder(s) fire too, the smoke clears up then its fine.
Try longer glows, 20-30 seconds, see if that works better. White smoke means the fuel is not burning from it not being hot enough. Black is excessive fuel or bad spray pattern causing it to not burn properly.

 

[mlsteele]

I glow mime longer than that. If i don't, it will start but run poorly till the missing cylinder(s) fire too, the smoke clears up then its fine.
Try longer glows, 20-30 seconds, see if that works better. White smoke means the fuel is not burning from it not being hot enough. Black is excessive fuel or bad spray pattern causing it to not burn properly.

The smoke is white or maybe whitish blue. It smells very rich. The machine runs great but just smokes on start up. How would you know if it was coolant causing smoke

 

[OldMachinist]

The smoke is white or maybe whitish blue. It smells very rich. The machine runs great but just smokes on start up. How would you know if it was coolant causing smoke

First sign that its coolant would be if you're having to add coolant to the system.
Likely the problem is a leaky injector or injectors thats dripping into the cylinder when its not running causing it to run rich until it burns it off. Does your oil smell of fuel? If it's a leaking injector then some of the fuel can seep down around the rings and get in the oil.
The other thing would be if one of the glow plugs isn't working.

 

[mlsteele]

First sign that its coolant would be if you're having to add coolant to the system.
Likely the problem is a leaky injector or injectors thats dripping into the cylinder when its not running causing it to run rich until it burns it off. Does your oil smell of fuel? If it's a leaking injector then some of the fuel can seep down around the rings and get in the oil.
The other thing would be if one of the glow plugs isn't working.

How do I check the injectors to see if one is leaking? How much are the injectors and where is the best place to get them?

 

[OldMachinist]

How do I check the injectors to see if one is leaking? How much are the injectors and where is the best place to get them?

The best way is to pull them out and take tem to a diesel shop and have them test them. If they find a problem they can rebuild or replace them.
For a at home test pull them out one at a time and reconect to the line with the nozzzle pointed in a safe direction and have someone crank the engine over a few times. Watch the spray pattern it should be a nice cone shape and shouldn't drip afterwards. This will give you a idea if one is bad but like I said a shop can do the testing right.

 

[Tazza]

The best way is to pull them out and take tem to a diesel shop and have them test them. If they find a problem they can rebuild or replace them.
For a at home test pull them out one at a time and reconect to the line with the nozzzle pointed in a safe direction and have someone crank the engine over a few times. Watch the spray pattern it should be a nice cone shape and shouldn't drip afterwards. This will give you a idea if one is bad but like I said a shop can do the testing right.

How does it run when warmed up? it could be a bad valve seat causing the compression to be low and it will smoke badly too.
I do the same as OM stated to test injectors. It works great for me.

 

[biggie]

Sounds like U have glow plug issues. 1 or more are not working. Replace is about $25 each. The part # should be3974953. If U can test the plugs seperatly,the ohms should be 1.5 give or take. 0 means pooched

 

[bobcat 743er]

i have the same problem, my relay is blown so i cannot warm up my glow plugs. so when i start my bobcat i have to take the filters off then spray some starting fluid in and then once it starts i get ALOT of white smoke, i went and bought some LUCAS INJECTOR CLEANER and its helping alot!! tomorrow i am going to buy a new relay, my battery moved and the positive terminal rubbed up against the back part of the bobcat and when i went to start it it shorted out the relay. so i replaced the ignition and that wasnt it. i had a mechanic check it out and he says my relay has power on 1 side but none to the ignition so hopefully that fixes it. but try the fuel injector cleaner, the 1st time i used it i pout it in the fuel tank and 30 minutes later i had soo much white smoke for about 30 minutes lol but now when i start it im getting less white smoke and its going away quicker,once the smoke goes away the bobcat runs bad ass, you can hear when the smoke goes away the bobcat sounds so much better, hope this helps you

 

[Tazza]

i have the same problem, my relay is blown so i cannot warm up my glow plugs. so when i start my bobcat i have to take the filters off then spray some starting fluid in and then once it starts i get ALOT of white smoke, i went and bought some LUCAS INJECTOR CLEANER and its helping alot!! tomorrow i am going to buy a new relay, my battery moved and the positive terminal rubbed up against the back part of the bobcat and when i went to start it it shorted out the relay. so i replaced the ignition and that wasnt it. i had a mechanic check it out and he says my relay has power on 1 side but none to the ignition so hopefully that fixes it. but try the fuel injector cleaner, the 1st time i used it i pout it in the fuel tank and 30 minutes later i had soo much white smoke for about 30 minutes lol but now when i start it im getting less white smoke and its going away quicker,once the smoke goes away the bobcat runs bad ass, you can hear when the smoke goes away the bobcat sounds so much better, hope this helps you

White smoke is unburnt fuel, you need your glow relay to work. You can jump a wire and power then direct and see if it starts propperly. The plugs may even be bad and need replacing.

 

[ZackaryMac]

White smoke is unburnt fuel, you need your glow relay to work. You can jump a wire and power then direct and see if it starts propperly. The plugs may even be bad and need replacing.

FWIW, I work at a Massey dealer, and we have a new compact tractor that is smoking some, and it's oil. I've often wondered if you can tell on a diesel if it's burning oil from the smell of the exhaust, and you can. It smells almost like a gas engine when it's burning oil - a definite oil smell, versus the choking diesel smell, or sweet smell/taste of antifreeze in the exhaust. I have a few small diesel engines, and they will smoke whitish/blue till they heat up, even though they aren't mis-firing. Their small displacement doesn't generate enough heat at first for a clean burn. I agree with the other guys, you may have injector issues.