Holley stumble trouble
^^^^This is what I’ve suspected the whole time. Question is, how to correct it? I’m not sure I’m interested in trying to drill out these tiny holes or press in new ones. Perhaps a replacement adjustable metering block is in order here. I briefly considered a ProForm main body but they do not come with blocks and there is no provision for a vacuum advance port if using my existing block.
Negative. It’s the primary. I’m gonna measure again to be sure but I was pretty careful the first time around.
Go make a sheet or table like I poisted or there's ones on Racing Fuel System as well.
Write everything down.
Since the mains started at different rpms, it wouldn't hurt to pin every bleed and restriction. One side could be different than the other.
Take out the jets and see if there are tubes. I'm betting not but......
My approach is normally the slow approach.
I'd do each of these seperately and take it for a drive.
* Plug those holes in the primary block's doglegs with fuel resistant epoxy - like for fuel tanks.
* Open the IAB's to something normal, but start on the small side - like .070
* MAB to .026
* IFR to .033, and then open the IAB a hair if needed
First one because I think it serves no purpose and is likely to be the root of the evit - assuming no e-tubes.
If there's e-tubes, then plug the eholes in the channel with some lead or a set screw.
Second because I agree this is an odd combo - maybe due to the holes in the doglegs but it aint doing the trick if that was the intent.
Third, if the above isn't doing it, then maybe the MAB is too small. .026 is not unreasonable.
Finally, if it really is running out of fuel in the idle circuit, then a larger IFR should keep it flowing to a higher rpm. A larger IAB may be needed to trim it to the same AFR as before.
