: anyone running the 4k gov spring kit notice a little flutter or pop in the exhaust just rolling along and slightly letting off the throttle say 1100-1200rpm? Psychoram and I both notice this, we wonder if it might be the extra fuel added at that low of RPM..? anyone else have the same issue..and could it be bad? or just normal

 

I've noticed it too, but considered it a quirk of using the 4k kit with 370's...too hard for it to control that rpm range. : Oh well I say, Just go past that rpm faster and you wont notice it that much .

 

This normal with hard fueling, the pump doesn't know what to do fuel or not fuel. Mine does it and always has at that RPM, if the RPM is too high were it happens you can back the springs off one click and it will lower the stumble, mine are at the first initial click then one more. A guy can get a good pump shop to balance the pump and get most of it out but it's likely that you will never get it all out. Some have said adding 191's will help this but it didn't with me, mine got slightly worse with 370's then 191's then Lasers, but helped with Timing and fuel pressure. I have my overflow valve shimmed for more pressure and it helps....25-30 PSI is good!<br><br>One mine it idles ok considering the bottom end fueling and runs hard from 1500-3400 were it needs to and cruises just fine.<br><br>Jim

 

YEAH..jim it didn't start til i added the 4k springs...was worried it was the valve springs or something, good to know.Hope it's not bad on the pump..

 

One thing you can do! Looking at your sig your fueled heavy, hook up an unlock switch using a dimmer switch in the floor then when your in that tight spot (25-30 in third fo me) unlock the converter....it helps allot!<br><br>Jim

 

Now that I have the Race Pump I can see what the hours and hours of labor on the flow bench are all about, I never would have believed that a Diesel would hum at idle but mine will, A dream to drive a really smooth pump.<br><br>Jim