Stumble off idle -

[Grubby]

Originally Posted by decooney

John,
For what its worth... I'm running primary 82s on my Holley HP830, and have tried both 6.5 and 5.0 PVs. One thought is I suspect the QFT carbs may be a tad leaner on the idle feed / transition circuit as we found out on my buddies QFT carb. He's got more freeflowing open sidepipes too. In the last run someone there at QFT told me they went down 2 sizes in the metering blocks for the idle feed restricters. So, we went back up two, and another two more again - something like 32 > 34 > 36 and it cured the problem. Not sure if this is your situation or not. Curious to know what you have in there now. If going with 82 primary jets up front and a jump in PV from 5 to 6 does not help, you might check with Phil at QFT and see (and measure) what size itty bitty jets are in the metering blocks for the idle feed restrictors. This is what I like about the QFT better than my Holley, way more adjustable. You can get the little restricter jets from Summit or Jegs too.

Duane,

I have the jets in but the weather is not cooperating. I will update all on what it takes to get the drivablility spot on.

After driving with the vacuum gage it became obvious the 65 PV is likely correct. Lean conditions occur when the vacuum is higher than 10 inches. It is possible a 75 PV may even work better, but let's see what the jetting does first.

I am thinking about idle feed restrictors as well. I am working through one piece at a time.

John