This isn’t what I am working on today but it was 2 weeks ago, it took a while to upload the photos and gather my thoughts on the job. Some interesting things hopefully others can learn from this.
My AMX started running rich towards the end of the summer. I intended to do a carb kit at some point so this was extra incentive. I also wanted to install a heat insulator gasket as I have always had a hot start issue from percolated fuel. Job went fine, these Edelbrock AVS carbs are really simple to work on and I love how they are just as configurable as a Holley, everything, pump shooters, pump stroke, jets, rods, power valve springs etc. I really like these carbs. Found two major issues.
1 – Passenger side float was full of gas. It can happen with brass floats and this was no exception. I installed two new floats, set the drop and float level to spec. All good. The one on the left is heavy with fuel.
2 – This was a weird one but I checked online afterwards and I was not alone. The small plug on the secondary booster cluster had fallen out (see pictures). I discovered it in the fuel bowl and, of course, found the hole in the cluster. It just presses in but this one worked itself out. I pressed it back in and used a small dab orange Loctite around the rim to seal it in place, same as the other one which has not fallen out. Orange Loctite is fuel resistant so it should be fine. This missing plug would only be noticeable at WOT / secondary opening and I never felt it (limited secondary usage, I live in a congested city… so not much WOT action) but it would have seriously impaired the mixture in that venturi.
Post checkout, car is running great again. Smooth, great throttle response, decent idle etc. Biggest bonus, so far, is that heat insulator gasket is working great, the couple stops I made (burgers and gas) no percolation. I’ll see next summer in the heat how it is. I have always had success with these insulator gaskets on my Holley cars too. My Q-Jet cars are pretty good from the factory against percolation.
Always check hood clearance when you increase the height of the carb / air cleaner. The insulator gasket is .3” high… the regular gasket was .060”… I have seen lots of hood damage from an oopsie here.
Anyway, here are a few pictures of the day.
Parts used:
Edelbrock Master Kit 1477
Edelbrock Float Kit 1469
Edelbrock Insulator Gasket 9266
Next up is some power valve tuning. I have the “orange” springs in (5”Hg) and I want to go to the “pink” (7"Hg) spring as I have a very slight mid-throttle sag when the engine is cold... pretty sure it isn’t the pump shot but it feels like the power valve is not lifting fast enough for the mid-throttle enrichment. I’ll see. It is easy to change these springs.
Desperately trying to find someone local with a synchrograph because I want to get into the ignition curve as well. I can do it with my dial back timing light and I pretty much know I want the lightest springs to get the advance in by 3000 RPM but it is tedious with the light, much easier with the synchrograph and the distributor pulled.
Other than the ball joints and brake components, trucks like new.
