I searched but couldn't find an answer to this... I installed my 3KGS last weekend and my truck runs great except for a very brief idle surge as the tach passes 1000 on the way down when I let of the throttle with no load. I just checked my measurements again and both sides are pretty much right where they were with the stock springs (.06). One was slightly out and tweaking it smoothed my idle a bit but I still get the surge/grunt as RPM fall below 1000.

Anyone know what causes this and how I can fix it? Any help is greatly appreciated!

Btw, I tried using the 'click' method to adjust the retainers but that seemed WAY too loose. I'd get 2 solid clicks WAY before I get anywhere near .06.

-john

 

Mine does it too, and it started with the gsk. It doesn't do it when the engine has warmed up, and it does it worse in colder weather. I have no idea why it does it, and it doesn't really bother me that much.

 

Mine also does it mostly when cold... still does it but not as bad at operating temp.

I'm not terribly worried about it, but if there's a fix I'll try to get rid of it.

-john

 

Mine also does it but very slightly - maybe 100 RPM (hard to tell exactly). It also started after the 3K GSK.

I kinda like it!

 

Piers calls it flutter and it is the downside of GSK.

Do you have an auto or manual?

 

Flutter, huh? Mines a manual. Does Piers say if there's a way to make it stop?

 

Did you leave the shims out? I did not put the shims in mine and do not have this problem.

 

I filed the springs in my kit so they were sure to have free travel.

The ends/edges were sharp and all I did was gently round off anything that might catch on another spring in the assembly. Maybe this is not necessary, but I don't have "flutter" and it took a minute a spring to do it. Pre-install of course.

Big Jim

 

Probably got the springs a couple clicks too tight.

I've done a lot of GSK and only screwed up 2 that required a little tweaking.
A 96 manual got too tight and a 95 manual was too loose

It is Ok to have one side a click tighter than the other side, too.

-John

 

I got one shim out of each side (didn't put them back in). Did you guys measure with calipers or did you just adjust by counting clicks? I'll try backing off a couple of clicks and see if that makes a difference.
-john

 

Well, I backed off the tension a couple of clicks and that only made the flutter/bounce/grunt worse. I guess I'll give Piers a call tomorrow.
-john

 

I've always kept the shims on the large outer (idle) spring if OEM. I guess it is about 50/50 for trucks that have them.

My method is for an experienced installer only. A combination of clicks, measurement, & pre-load on the spring stack.
Basically I reset the GSK to OEM setting and then adjust based on what my fingers tell me about the pre-load tension on the springs.

-John

 

Mine does this as well, except mine is stock as far as I know. It is only when it is cold or not fully warmed up.

 

Well, perseverence pays off I had to go back in two more times and I ended up backing off two more clicks still and adjusting my idle up and that took care of the idle bounce problem. Idles up and down just as smooth as can be and I still have all the RPM benefit of the 3KGS. Where my retainers sit now they are just flush with the end of the stud so it's nowhere close to where it was with the stock springs. Oh well...
-john

 

Glad to be of help.
You should only notice flutter when the engine is cold.
The throttle response from idle to 3,000 (or more) should be a lot smoother and linear, too.

-John