Hi Gang,
I'm still working through the kinks on my 67 fastback. It is a re-built 289 (302 block) with what I believe is an Autolite 4300 4v carb & C4 transmission that the PO had installed 20 years ago.
One thing I noticed when I would drive it is if I tried to goose the throttle, it would 'fall off' then kick-in... A significant hesitation. I wanted to verify the timing. It was way advanced - maybe around 12 degrees or more. It took me over a week to free-up the distributor to be able to adjust it. I put it back to 6 degrees BTC & it ran worse. I opened up the distributor & it looked pretty nasty in there, so I took apart the internals of the distributor down to the springs/weights & cleaned it all up/put it back together. I tested the vacuum advance unit & it functions/holds. I don't have anything more than a basic timing light & a DVM, so my diagnostic tools are limited. After putting the distributor back together, I could hardly give it gas at all without the engine wanting to shake out of the mounts. When I would disconnect/cap the vacuum line off the distributor to re-check the timing, it actually ran better. SO - I played with the throttle & adjusted the vacuum advance unit's screw until I figured I had it smoothed-out. When I took it for a run, it seemed to perform alright... the hesitation on acceleration is still (periodically) there like before... but now when I am at steady speed for a few minutes, it starts to run rough, like it's missing or something. If I let off the gas, or give it slight acceleration, the roughness goes away. Doesn't matter what speed I'm at.
I've read quite a few posts on the whole vacuum advance topic... Some of them are quite involved. I'm wondering if there is an easy way to adjust/set it up when you don't have all kinds of diagnostic tools handy. I suppose I could just advance the timing a bit & plug the line that goes to the distributor & run it like that for now, but I don't want to leave it that way. If I have to spend some $$ I'd like to make sure I'm putting it in the right place... do I get a tach, do I replace the whole distributor/rebuild? It still needs to be set-up...
Any suggestions welcome...
Thanks,
R.R.
I'm still working through the kinks on my 67 fastback. It is a re-built 289 (302 block) with what I believe is an Autolite 4300 4v carb & C4 transmission that the PO had installed 20 years ago.
One thing I noticed when I would drive it is if I tried to goose the throttle, it would 'fall off' then kick-in... A significant hesitation. I wanted to verify the timing. It was way advanced - maybe around 12 degrees or more. It took me over a week to free-up the distributor to be able to adjust it. I put it back to 6 degrees BTC & it ran worse. I opened up the distributor & it looked pretty nasty in there, so I took apart the internals of the distributor down to the springs/weights & cleaned it all up/put it back together. I tested the vacuum advance unit & it functions/holds. I don't have anything more than a basic timing light & a DVM, so my diagnostic tools are limited. After putting the distributor back together, I could hardly give it gas at all without the engine wanting to shake out of the mounts. When I would disconnect/cap the vacuum line off the distributor to re-check the timing, it actually ran better. SO - I played with the throttle & adjusted the vacuum advance unit's screw until I figured I had it smoothed-out. When I took it for a run, it seemed to perform alright... the hesitation on acceleration is still (periodically) there like before... but now when I am at steady speed for a few minutes, it starts to run rough, like it's missing or something. If I let off the gas, or give it slight acceleration, the roughness goes away. Doesn't matter what speed I'm at.
I've read quite a few posts on the whole vacuum advance topic... Some of them are quite involved. I'm wondering if there is an easy way to adjust/set it up when you don't have all kinds of diagnostic tools handy. I suppose I could just advance the timing a bit & plug the line that goes to the distributor & run it like that for now, but I don't want to leave it that way. If I have to spend some $$ I'd like to make sure I'm putting it in the right place... do I get a tach, do I replace the whole distributor/rebuild? It still needs to be set-up...
Any suggestions welcome...
Thanks,
R.R.