Setting High Idle

[jbolt]

Ok I've been told two different methods now.



1. Set the max RPM in neutral.



2. Set the max RPM by driving in second gear.



So which is it? Oo.



Jay

 

[formula]

I would recommend that you set the high idle under no-load (neutral or park). The no-load speed will be around 200-300 rpm higher than the defuel rpm. The reason for this is that the extra rpm is needed to spin the flywheights on the governor fast enough to produce the necessary force to overcome the spring tension. I don't think it makes sense to set the high idle in 2nd gear as the engine will have a load on it and you won't get an accurate reading. 2nd gear can be used to find your defuel point though. The reason for using 2nd gear is that you'll be going at a relatively safe speed while taking readings. If you try it in 3rd, you'll probably be at about 70mph, and in OD around 100mph.



Cheers,

Sean

 

[Old Smoky]

Setting the high idle in second gear is a good way to go. Just floor it in second gear and at the point where it "falls on its face" is the defueling rpm. This is usually set to about 2900-3000rpm. The high idle can be set in neutral, this no load rpm will be higher than the defueling rpm.



Mike

 

[Old Smoky]

O. k. formula, you're doing this on purpose now, aren’t you?



It depends on if your setting load, or no-load rpm.



Mike

 

[formula]

Originally posted by Old Smoky

O. k. formula, you're doing this on purpose now, aren’t you?

:-laf never, never



Check out this thread for a description on how to perform the high idle adjustment https://www.turbodieselregister.com/forums/showthread.php?threadid=58462&highlight=2900



To make things easier, just set the no-load rpm first. Then take it out for a drive and see how you like it. Then make further adjustments if necessary.



Sean