Idle

[rodpaslow]

I've read some post in this forum about mtdi idle.  I'd like mine to be a bit higher right around 800-850. If I adjust the fuel screw down and adjust the idle back up it will start to hang at about the same spot every time.  Is there a trick to getting it higher without it hanging?

I've also read a post about injectors.  I know mine need to be changed.  I get some blue smoke at startup and first minutes or so when cold (around 32°F, 0°C).  Would re-newing/changing nozzles help this and the idle?

[libbydiesel]

It sounds like you may be fully compressing the idle spring.  You may want to stretch it a little.

[rodpaslow]

Thanks.  I think I may change the nozzle first.  See what happens and if I still need to pull the top off and see if I can do that.  I have a few other pumps, would replacing the idle spring with a stronger one do the same thing?  the LR spring seemed pretty weak to me.

[libbydiesel]

Yes, a stronger idle spring would accomplish the same thing.  I don't recall what idle spring I used in my Rover pump.  I think it was the stock rover spring.  Idle is rock solid at 890 rpms.  On Cummins 4BTA base pumps I always used the Cummins spring and idle is always solid. 

[vanbcguy]

My Rover pump definitely wants to idle right around 900 too. I have it bumped up slightly from there for vibration purposes but you can let the clutch out and it will hold about 850-875 happily.