Too Soon Old, Too Late Smart

[bsekf]

My new/old 7030 sometimes starts hard. I've thought starter not fast enough, bad battery, bad connections, bad glo plugs. BUT, the last few times I have tried to start the tractor I've left the throttle very low, about 500 rpm's, and it starts right up. Did I stupidly veer into the proper procedure for my tractor or is that the correct way to start a diesel? Or, does it indicate a problem? I've always set the throttle about half way, 1000 rpm's, before starting. Have I been doing it wrong all these years?

Bill

 

[big bubba]

i always start at idle rpm, around 800. certainly wouldn't want to start @ 1/2 throttle in the winter months. actually anytime. let the oil seek out it's job 1st before higher rpm

 

[tacticalturnip]

I can't say I've ever throttled up my diesels before starting them; I can't tell you of any possible effects from that, I've just never done it.

 

[Doughknob]

Interesting. On my new Bobcat with Deadong engine, no matter where I put the throttle lever, the tractor starts at idle. I actually have to move it up/down a cycle to even get it to throttle up when I am ready to go.

 

[Eagle1]

Always start at idle unless I forgot to set the throttle back when I shut it down (rare)

 

[5030]

My new/old 7030 sometimes starts hard. I've thought starter not fast enough, bad battery, bad connections, bad glo plugs. BUT, the last few times I have tried to start the tractor I've left the throttle very low, about 500 rpm's, and it starts right up. Did I stupidly veer into the proper procedure for my tractor or is that the correct way to start a diesel? Or, does it indicate a problem? I've always set the throttle about half way, 1000 rpm's, before starting. Have I been doing it wrong all these years?

Bill

As with any mechanically injected engine, you always start it with the throttle set at base idle because the pump internally will advance the fuel to 100% on start up and instantly reduce it back to base idle when it starts. How they work. Electronically injected engines (common rail) are different I'm sure.

 

[JWR]

As with any mechanically injected engine, you always start it with the throttle set at base idle because the pump internally will advance the fuel to 100% on start up and instantly reduce it back to base idle when it starts. How they work. Electronically injected engines (common rail) are different I'm sure.

I own 4 Kubotas -- 3 older B2150 4 cyl and one BX2200 3 cyl. None of them reduce back to idle once they start. They go straight to whatever I have the throttle set at. Have not tried it on the larger MF2660 yet.

 

[big bubba]

on the flip side of a work detail, i'll always let it idle a few minutes before shutdown. mainly for turbo, but a good practice anyway on agri or small engines, etc.

 

[Ferpen]

The start procedure in the operator's manual for my Kubota L3901 states to "set the hand-throttle-lever to about 1/2 way."
It also states to slow the engine to idle before turning the engine off.

 

[ljjhouser]

The start procedure in the operator's manual for my Kubota L3901 states to "set the hand-throttle-lever to about 1/2 way."
It also states to slow the engine to idle before turning the engine off.

Same in the manual for the L4701.

 

[loggin]

I usually start at just above idle. Somewhere around 1000 rpm. I feel as though the oil pump might develop pressure a little sooner at the slightly higher rpm. I do not believe it will cause any greater damage at that level.

Just my 2 cents..

 

[Thomas]

I let idle lowest rpm for couple mins the rise rpm 1500 than slowly exercise attachment more so in the winter.

 

[5030]

I own 4 Kubotas -- 3 older B2150 4 cyl and one BX2200 3 cyl. None of them reduce back to idle once they start. They go straight to whatever I have the throttle set at. Have not tried it on the larger MF2660 yet.

Maybe I should distill that a bit for you.. You leave the throttle at the idle setting prior to starting and the injection pump (if they are mechanical) advances the throttle internally to 100% until the motor starts and then immediately returns to the throttle setting you have set, in my case, base idle. How they all work (at least Bosh style pumps) like are on Kubota tractors. My big truck with it's Cat 3406 operates exactly the same way. maximum fuel on start, immediate reduction on firing. One reason why Cats start so well in the winter, that and their base compression ratio is so high.

 

[5030]

I let idle lowest rpm for couple mins the rise rpm 1500 than slowly exercise attachment more so in the winter.

Exactly what I do and I never plug mine in in the winter either (no juice in the barn anyway). Pre heat the glow plugs about 20 seconds are crank it. Usually starts right up at an idle. Then I'll run the rpm up to about 1000 and go have a cup of coffee. Some banging and clanging going on but that is all combustion noise.

When they sit in the barn, the fuel tanks are full (to reduce tank condensation) and I shunt the batteries out of circuit too. When I need them, I close the shunt and start them up. That way no chance of any parasitic drain on the starting battery at all. Flooded cell batteries are real efficient at maintaining a charge, especially in the cold weather. Both have block heaters I've never used.

 

[bsekf]

Manual says "half throttle" (1000 rpm) and then reduce after it starts. But I've found it starts better with a low throttle setting (500 rpm). Will be interested to see what happens when the weather gets colder. No turbo on the 7030, but I still let it idle for a few seconds before shutting off.

Thanks for the replys.

Bill

 

[5030]

Manual says "half throttle" (1000 rpm) and then reduce after it starts. But I've found it starts better with a low throttle setting (500 rpm). Will be interested to see what happens when the weather gets colder. No turbo on the 7030, but I still let it idle for a few seconds before shutting off.

Thanks for the replys.

Bill

I presume that is a common rail, high pressure injection engine and not a mechanically injected engine correct? If so the ECM determines the initial cold fueling rate, not the fuel rail in the injection pump. In reality, you only need to idle a turbo charged motor so the hot side bearings in the turbo can cool down and not turn the now not circulating engine oil to 'coke'. The leading cause of turbo failure is the hot side bearings fail. Pretty easy to tell too. Just remove the intake hose to the turbo and grab the impeller and wiggle it. If it wiggles, it's on it's way out. Once it gets excessive radial play, the impeller hits the scroll housing and destroys itself and the engine too because the 'shrapnel' from the impeller gets ingested in the motor and eats it up.