Hi. Just got done syncing the carbs on my FJ ('93, Uni's, #40 pilots, 2 1/2 turn mixture, rebuilt by Randy about one to 2 years ago) with the Carbtune. All went well & it seems to idle/run better (time will tell). I have always found that the #1 cylinder mercury bounces continuously (steadily) while the others are very steady. Any thoughts on what cause this & what can be done? Thanks.
Add some in-line needle valves to restrict the vacuum, just enough to smooth out the bounce. I saw them work really well on the gauges Randy uses.
You should not add valves on a carbtune, only use the restrictors supplied with the carbtune. It is finely tuned to work with the restrictors and nothing else.
First: Rule out the Carb Tune:
Swap hoses. Swap #1 hose with #4 and see if the bounce follows (i.e. the #4 column now connected to the #1 cylinder continues to bounce)
4everFJ is correct....add nothing to the vacuum lines.
Assuming all the Carb Tune line restrictors are in their proper place and clean....and the Carb Tune is hung vertically (no side loads on the ss rods)
Are your valves adjusted? That's important. A tight leaking valve (typically exhaust valve) can cause different vacuum readings...
Assuming that is done...
Check your (hot) compression numbers. See if #1's any different than the others.
That's about all I got... HTH Pat