A
Anonymous
Guest
OK, so after reading about the timing and all the related issues, I decided to try a few things...
1. I pulled both air/fuel mixture screws and they are fine, clean and not bent, although one was 1 1/2 turns out and one was 2 1/4 turns out, this is not good, since they should be equal. I set them both to 1 1/2 turns.
2. From a cold startup here are the tuning numbers, vacume 16inches, idle 1600 timing 35 degrees (dialed back to 0 on the light!)
As it warmed up this fell down to 1000 rpms, 12 inches of vacume, and 25 degrees in the timing light. Once the choke was completely open it did it's usual attempt to stall and the vacume dropped to 6 and then almost 0... but it holds a vibrating and steady needle at 16 until it warms up.
Then if I can get it going a bit, it sits shaky at 12 inches.
I had at this point the PCV line hooked into the base of the 2300. The vacume advance hooked into the "Ported" source at the carb on the metering block. and the gauge on the tree.
First I decided to pull the vacume gauge off the intake tree on the manifold and hook the advance line from the carb striaght up to the intake manifold tree.
When I pulled the line the enigne rpms increased and it smoothed out just being open.
Then I hooked the advance line up and the rpms increased more, so I decided to back the curb idle down now with the advance hooked to full manifold, I got the rpms down to 800 with no missing or stumble, a little shaky, but nothing like before, and it idles really much better in the 800 to 900 range than it did hooked to ported source.
I hooked the gauge up to the "Ported" source and get a 0 reading at idle, I get a 7-10 inches reading at throttle from 1200-1600 rpms... on that ported source of vacume from the metering block.
with the advance line on the dizzy hooked to the ported source I measure 16 degrees initial with that line pulling no vacume, if you pull the line it has no effect on the timing. Like I posted before.
With the advance line hooked to the intake manifold getting full vacume I get a reading of about 30 degrees at idle running at 800 rpms (shaky)... but if I pull the vacume line to set the timing it drops the engine so low it dies. Also the timing at this rpm range is a little jumpy, meaning the mark jumps a bit, and it is hard to get a reading on, but that may be from what sounds like the timing being advanced too far with this much vacume pulling on the diaphram. I need to back it down from here and adjust the idle if I am going to run with full vacume. but I want some opinions on this information first...
so my questions are?
is the ported source supposed to have 0 vacume at idle? if so then that would have no affect on the timing.
is is better to run with ported vacume? Full vacume? or no vacume?
how can I set this up to be correct?
Thanks
1. I pulled both air/fuel mixture screws and they are fine, clean and not bent, although one was 1 1/2 turns out and one was 2 1/4 turns out, this is not good, since they should be equal. I set them both to 1 1/2 turns.
2. From a cold startup here are the tuning numbers, vacume 16inches, idle 1600 timing 35 degrees (dialed back to 0 on the light!)
As it warmed up this fell down to 1000 rpms, 12 inches of vacume, and 25 degrees in the timing light. Once the choke was completely open it did it's usual attempt to stall and the vacume dropped to 6 and then almost 0... but it holds a vibrating and steady needle at 16 until it warms up.
Then if I can get it going a bit, it sits shaky at 12 inches.
I had at this point the PCV line hooked into the base of the 2300. The vacume advance hooked into the "Ported" source at the carb on the metering block. and the gauge on the tree.
First I decided to pull the vacume gauge off the intake tree on the manifold and hook the advance line from the carb striaght up to the intake manifold tree.
When I pulled the line the enigne rpms increased and it smoothed out just being open.
Then I hooked the advance line up and the rpms increased more, so I decided to back the curb idle down now with the advance hooked to full manifold, I got the rpms down to 800 with no missing or stumble, a little shaky, but nothing like before, and it idles really much better in the 800 to 900 range than it did hooked to ported source.
I hooked the gauge up to the "Ported" source and get a 0 reading at idle, I get a 7-10 inches reading at throttle from 1200-1600 rpms... on that ported source of vacume from the metering block.
with the advance line on the dizzy hooked to the ported source I measure 16 degrees initial with that line pulling no vacume, if you pull the line it has no effect on the timing. Like I posted before.
With the advance line hooked to the intake manifold getting full vacume I get a reading of about 30 degrees at idle running at 800 rpms (shaky)... but if I pull the vacume line to set the timing it drops the engine so low it dies. Also the timing at this rpm range is a little jumpy, meaning the mark jumps a bit, and it is hard to get a reading on, but that may be from what sounds like the timing being advanced too far with this much vacume pulling on the diaphram. I need to back it down from here and adjust the idle if I am going to run with full vacume. but I want some opinions on this information first...
so my questions are?
is the ported source supposed to have 0 vacume at idle? if so then that would have no affect on the timing.
is is better to run with ported vacume? Full vacume? or no vacume?
how can I set this up to be correct?
Thanks