I’m just about installing turbo to my 3B and try to learn how to adjust the inline fuel pump the right way. I’d like to keep the economy and avoid increasing fuel to the power band where it’s not needed, but there should be the possibility to get all needed fuel when floored.
I have never seen or heard told here that the venturi nipple is turned or the hose of it is manipulated.
I have read that turning it 180° would help quite a lot by giving much more fuel under the boost. Normally it reduces fuel when higher rev’s ”ram air” through the nipple starts to push the diaphragm back in the vacuum chamber. Charged air is heavier, so the fuel compensation starts too soon and in the wrong direction. By turning the nipple to the opposite direction allow the fuel delivery increase to the end. The rev limiter is not working properly because of that. The position of the turned nipple is told to be very accurate (the angle and how deep the nipple is). About 1.5 turn more inward might be about the right.
The other solution is install a bleed valve between the hose or drill about 2-3 mm hole to the hose near the fuel pump.
The diaphragm spring may need to stretch or shim longer, or change longer spring because of the increased vacuum, otherwise the rod may not keep in the max fuel position when needed.
Also some of you said that the timing should retard few degrees, but I’ve heard that by advancing it the consumption and power is the best.
Thoughts?
I have never seen or heard told here that the venturi nipple is turned or the hose of it is manipulated.
I have read that turning it 180° would help quite a lot by giving much more fuel under the boost. Normally it reduces fuel when higher rev’s ”ram air” through the nipple starts to push the diaphragm back in the vacuum chamber. Charged air is heavier, so the fuel compensation starts too soon and in the wrong direction. By turning the nipple to the opposite direction allow the fuel delivery increase to the end. The rev limiter is not working properly because of that. The position of the turned nipple is told to be very accurate (the angle and how deep the nipple is). About 1.5 turn more inward might be about the right.
The other solution is install a bleed valve between the hose or drill about 2-3 mm hole to the hose near the fuel pump.
The diaphragm spring may need to stretch or shim longer, or change longer spring because of the increased vacuum, otherwise the rod may not keep in the max fuel position when needed.
Also some of you said that the timing should retard few degrees, but I’ve heard that by advancing it the consumption and power is the best.
Thoughts?