Idle bounce!

[SOOT]

My truck just started doing this only when the outside temp is above about 70 degrees, its more pronounced when the engine warms up. Its almost like a lope but consistent. The tach holds rock steady but I can hear it and feel it, it rocks the whole truck

Its kinda cool actually



Any ideas?

 

[Wirenut]

Mine did this when I installed the 370 injectors but only when it was cold. Ever hear an old MACK do this? Kinda reminds me of that.

 

[pwknapp]

I put 370's and the 3k gsk in at the same time and have readjusted it every way I am capable and it still lopes. Gettin' so used to it I just smile when I get those early morning looks.

 

[SOOT]

I kinda like it



I was just wondering if it was a syptom of something that might fail



Thanks for the replies, I guess I have nothing to worry aboutOo.

 

[HoleshotHolset]

How would one go about adjusting their governor springs so that the idle lope was MORE pronounced? *EVIL grin*



Matt

 

[SOOT]

HUMMMMMMMM... ... ... .



I like that idea



SOOOOO is there a way "EVIL GRIN"

 

[HoleshotHolset]

I know that big 'ole injectors will cause a bit of an interesting idle..... but I'm sure we could 'adjust' our governor so that it would bounce a little at idle... .



Matt

 

[SOOT]

Maybe like the 2 Stroke Detroits?



Maybe, just maybeOo.

 

[radixr]

Matt,



You want an idle lope? Tighten up your 4K or 3K governor springs a couple clicks and fasten your seat belt!Oo. Oo.

 

[HoleshotHolset]

I would LOVE to have my 6BT idle like a race 2-stroker Detroit (that reminds me... I still have to transfer those videos..... )... just for car shows or cruising, etc.....



I thought that having the springs too tight would reduce the idle speed? This would make it lope too??!!



Let's get this straight while we're at it... .

This is how I have interpreted it... . and I could be wrong.



Governor spring adjustment:

Too 'loose' = idle RPM raises, less overall fuel, less top end RPM...

Too 'tight' = idle RPM drops, more overall fuel, more top end RPM...





Matt - just ended a ~1200 mile road trip - I'm beat... . so hopefully the 'good' info on this will be uncovered in the AM... .

 

[radixr]

Loosen the gov. springs, idle rpm drops and vice versa.



Matt, I don't think tight gov. springs will give you a race car idle. They will make the engine surge at light throttle which is not a desirable trait. :{

 

[HoleshotHolset]

Surging would not be cool..... a sweet idle would be!

Thanks for the info!



Matt

 

[DT]

In the injection pump industry, this is known as "droop". Most pumps have a "droop" screw to put just a little more tension on the governor springs. This also raises your idle at the same time.

I know that right on the back of my pump, there an acorn nut and beneath that is a little adjustment rod with a stop and a lock nut.

My engine was doing this when I first got it, but not since I adjusted it.



http://www.picturetrail.com/turbokid



1984 3/4 ton Chevy

6BD1TA Isuzu Turbo Diesel (Straight six, 5. 8 Liter, Direct Injected, custom intercooler, Chrome liners, replaceable valve guides and seats, tuftrided crankshaft, big injectors, inline pump, etc. )

With an Allison AT542 and an NP208 TC behind it.

Straightpiped 3" with 4" tip.