Tuning a Proform/Holley carb, what parts and tools?
I did. It ran good at first, then total crap.
I took it to my normal spot, as I hit third at about 90mph I could feel it falling flat.
If I get on it from a dead stop and let off, it dies.
If I get on it starting from 20 and let off, it dies.
Even died on ne twice in a grocery store parking lot at idle, and must be flooding because it would not fire back up without holding the pedal down.
While my amatuer tuning attempts might be contributing, I think I may have a fuel issue and or ignition issue or both. I just replaced plugs and wires. Starting to suspect the coil or voltage regulator, and or fuel pump.
I have had issues with three different carbs now.
I worked all night and I'm so tired and pissed. I might pull the plugs, but getting into the carb will have to wait.
I didn't realize you were also trying out high speed WOT. Be patient on that. Get the idle much closer first (which also means steady cruising up to around 40-50 mph).
So first, just get the fuel level about in the middle of the sight glass for both primary and secondary. Then readjust the idle mix screws. Test the how it responds using as little accelerator pump as possible.
As far as the other possibilities for problems.
Since you cleared the carb using the throttle wide open technique, flooding seems to have been the problem at least that time. That's too much pressure for the needle and seat, or just set too high. Check that out first.
Next check out the choke, make sure its opening up quick enough. Also, see if you can observe whether it has an internal 'qualifying'. That is, as soon as the engine fires, manifold vacuum pulls the choke open. Original mopars from 60s and 70s have this as an external vacuum pod on the choke assemble. Most aftermarket carbs have this as an internal passage or some don't bother.
Back to the carb tuning. It will be iterative, but the sequence is also important. The idle circuits draws on the mains. They also can act in reverse at when wide open throttle. This is why the best tuners spend time working the "idle circuit" first. It saves time in the long run. "Idle circuit" includes the "transition" slot and starts with getting the throttle position in the correct range. Refer to that sidebar in
Holley Carburetors and Manifolds For street and return road etc, only the primaries transition slots are in play. So don't move the secondary throttle position very much from factory setting at this point. Secondary transfer slots are sometimes higher up than the primary side. So they may or may not have slot showing under the throttle blades at idle. Just note what you find when you take the carb off and map it out.
