Super MD starting question

Dan MD · Oct 17, 2011

When switching from gas to diesel, my tractor revs up a lot without even turning on the diesel injection pump. I wait until it starts to die and then I turn on the injection pump and it idles ok. I am in the process of getting the motor overhauled due to blowby and other issues that may be part of the problem. Tonight when I fired it up in the 50 degree temp range, it really reved up compared to what it did in warmer ambient temps. What could be causing this? I don't want it doing this after I get it rebuilt if it is going to hurt things. I already had the entire injection system redone and it is doing this after all of that work.

Thanks,
Dan

LaBoyteaux · Oct 17, 2011

My understanding of this system, you are supposed to advance the diesel throttle and throw the switchover lever simultaneously. I think if you just throw the switchover lever first you would be dieseling on gasoline at increased compression which might explain it speeding up.

sflem849 · Oct 17, 2011

(quoted from post at 18:29:31 10/17/11)
My understanding of this system, you are supposed to advance the diesel throttle and throw the switchover lever simultaneously. I think if you just throw the switchover lever first you would be dieseling on gasoline at increased compression which might explain it speeding up.

I believe you have it backwards. The manual says* that you should advance the throttle until you inject a little diesel and then pull the decompression lever. When you shut down the manual says to use both levers simultaneously.

* Many people have anectdotal experience that is different than what the book has to offer. Right or wrong, it works for them.

D Slater · Oct 17, 2011

Try letting it warm more before switching.

Anonymous-0 · Oct 18, 2011

i have a 400d and i just switch them both over at the same time. i throw the compression lever and open the diesel up to about 1/2 throttle. it speeds up and then it slows itself back down a little. i think its just the nature of the beast when it starts burning diesel.

sflem849 · Oct 22, 2011

(quoted from post at 18:28:01 10/22/11) I always bump the diesel throttle barely over the stop and then switch the compression on both of mine, and they switch over smoothly, if warmed up properly on gas, just a whiff of smoke and then rattle rattle rattle

That's what I was trying to say. When you throttle up it will actually start to pull the decompression lever for you. It talks about it in the book.

MeanGene1 · Oct 22, 2011

I always bump the diesel throttle barely over the stop and then switch the compression on both of mine, and they switch over smoothly, if warmed up properly on gas, just a whiff of smoke and then rattle rattle rattle

Super MD starting question

Dan MD

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LaBoyteaux

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sflem849

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D Slater

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Anonymous-0

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sflem849

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MeanGene1

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