The mysterious Holley... Reply #15 – November 12, 2006, 06:28:48 PM Quote from: sum_weirdo;113041Yay! I got the floats adjusted right. No more flooding or fuel starving. But something is still off, the vacuum reading at idle keeps jumping around mostly between 17-19 inches (sea level). That's well within the green "good motor" range of the gauge but I know it's not supposed to search back and forth like that. I tried tuning the mixture to no positive effect. It's on my mind that if there was gunk on the needle/seat then it's entirely possible it's in the jets or even the metering block itself. Sound logical? I'll probably take it apart later and see.could be a vaccume leak or the air adjustment not set correctly. Does the car have a aftermarket cam? Quote Selected
The mysterious Holley... Reply #16 – November 12, 2006, 07:19:41 PM It has a non roller HO cam. Nothing too aggressive. I've started wondering if the plugs became gas fouled when the carb kept flooding over. I'm also going to make sure there's clearance between the throttle arm and the accelerator pump arm in case it's leaking small amounts of fuel into the engine at idle. I guess I can look again for vacuum leaks, we'll see. Quote Selected
The mysterious Holley... Reply #17 – November 12, 2006, 09:27:15 PM Well I just checked the accel pump and it was being pressed down on with a fair bit of tension. I adjusted it to spec and we'll see in the morning. Out of curiousity what would you guys consider a normal mixture screw setting for a Holley on a Mustang-esque 302? Ford Muscle says if you have to go more than 2 then you have some kind of problem elsewhere. Quote Selected
The mysterious Holley... Reply #18 – November 13, 2006, 09:53:57 AM Quotethe vacuum reading at idle keeps jumping around mostly between 17-19 inches (sea level).Pretty much the same thing found in most repair manuals:http://www.classictruckshop.com/clubs/earlyburbs/projects/vac/uum.htm Quote Selected
The mysterious Holley... Reply #19 – November 13, 2006, 04:52:02 PM Okay I started the car again and didn't change any settings, I just observed for a bit. And one thing in particular caught my interest. The cheap plastic fuel filter in the line just in front of the distributor was nearly full of gas at first and the car ran smooth enough but after a while the level of gas in the filter dropped lower and lower until it was almost empty (see picture). The car maintained its RPM but was getting moderately rough. I don't know if that's remotely normal behaviour for a fuel filter but if it isn't it seems I have a problem. I know your first thought would be bad pump but that's a Holley pump, less than a year old and it never gave me any trouble until the carb swap (although I didn't used to have a see-through filter). Any other ideas about this? Could the fuel be vaporizing in the line? I don't know.... Quote Selected
The mysterious Holley... Reply #20 – November 13, 2006, 05:44:16 PM Starting to lean towards this being vapor lock....Incidently I never used an inline filter before because the stock carburetor used a small brass one that screwed into the bowl. I know my Holley has filters in the bowl that are meant to be secondary only and they warn that I should use an inline filter as well. I finally looked up a picture of one of those filters and presumably this is one in the picture below. Certainly looks as competent as any filter I would have had. Has anyone relied solely on them? Cause I think this oversized junk filter I'm using is providing a place for vapor to build and hold back fuel flow. Quote Selected
The mysterious Holley... Reply #21 – November 13, 2006, 07:19:51 PM Okay I just came back from a parts store and one guy brought up the possibility that I need a spacer plate to further insulate the Holley because it may be overheating and forcing vapor down the line. Right now all that stands between the carb and the manifold is a felt gasket so I guess it's possible. I didn't do any more because clearance is limited, maybe I can fit something small though. Quote Selected
The mysterious Holley... Reply #22 – November 13, 2006, 08:00:30 PM Just ordered a .25 inch heat disappator plate. Wish me luck. Quote Selected
The mysterious Holley... Reply #23 – November 13, 2006, 08:50:15 PM Quote from: sum_weirdo;113363Just ordered a .25 inch heat disappator plate. Wish me luck.should help some, the filters they do ok but ive seen dirt get past them i like to use the clear fuel filters like the fram G6 . Quote Selected
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