A little background on Ahstray's car: A year ago June, the car ran fine after installing a chain and gear, back when the fuel pump eccentric was loose, not allowing the pump to pump gas.
Later, it developed a hesitation. The first thing we checked was the accelerator pump--of course after breaking the fuel line and verifying that the pump pumped enough volume, plus a full bowl--and it didn't even sputter.
Installed a new acc/pump, test drove the car, and it still hesitated although Ashtray said that the car accelerated stronger than ever before.
We replaced the boarderline points/condensor and set the dewll a hair under 30'. We set the dwell a nanohair under 30' because we were using a Mickey Mouse hex wrench. We also replaced the cap and rotor, moreso because Ash had a new one, than because it was bad.
(IF ANYONE HAS A LINK FOR A POINTS SETTING TOOL, A HEX KEY ON A FLEX SHAFT, PLEASE POST. I used to have one until a whistelbritches punk kid stole it a few years back.)
The mechanical advance was sticking, so we weasel piSSed it up with wd-40. We put it back together, and it still had a hesitation, but Ashtray said that--hesitation notwithstanding--the car was running even stronger. At least we're making some headway and not going backwards.
On the next and latest bout, I rechecked the advance, wondering whether or not it was still sticking, but the advance was freed up and working fine.
Of course there can be other issues causing the hesitation, but it's acting like an accelerator pump issue. Light throttle is okay, but a slight rap or more on the gas, and it hesitates, even stalling.
I rechecked the acc/pump shot, and as I had origionally wondered when we put the cab back together, the shot wasn't/isn't what I consider a sufficient shot of gas. We verified the pump volume by crnking/disconnecting the gas line. Ran the engine to ensure a full bowl, then checked the acc/pump shot.
The problem with this diganosis is a case of wheter or not my opinion is accurate. (It's a rod 2bbl.) Yes, the pump provides a shot, but I don't know what is considered a healty shot from a 2bbl. If it were a quadrajet, the pump shot is unsatisfactory, but it's not a quad, so it's a different ballgame, and the acc/pump shot just may be VOTS (vehicle operating to specifications).
With a quadrajet, when you crack a quad throttle, in addition to a hard stream of gas, and you can feel the pump's resitance. If you continue to pump the throttle to the point where the pump cannot shoot, you can feel the lack of resistance as the pump goes dry.
With the 2bbl, there is a shot of gas; the question whether or not it's sufficient. Another thing that I'm unfamiliar with is, unilike the quad, you cannot feel resistance when you crack the throttle, meaning that you cannot feel a difference in the resistance as the pump goes dry.
Of course there are other issues that could cause hesitation, but we're pi$$!ng in the wind if we cannot determine whether or not it's a sufficient acc/pump shot.
Does a 2bbl have a similar shot as a quad? I would think that a 2bbl would have a similar shot as a quad, perhaps even more because the larger venturies would require a larger shot.
sounds like timing to me. too much retard in the timing? or the distributor might have a worn shaft and needs rebuilt. possibly the springs on the centrifuge might be worn out? also check for vaccume leaks (cracked lines). good luck
There are some vacume lines that should be replaced. The weights/springs seem to be in order. The timing has always been something that I have seen as an issue. It acts as if it's late with a lot of fast cranking. But if the accelerator pump is staving the engine, it would net similar results.
We have played with the timing since day one, and the initial setting is about at its max, with the hot start issue coming into play. (It has been varied in the 6 to 14 range, with it @ about 12.) The problem with the timing is that the engine acts as if it would like more timing, but @ 14, it wont crank.
If you back the timing a hair below 12, it flat out won't start. On my car, it has a farily healty sweep on the dist and still start. On Ash's car, however, it's a narrow band, right around 12'. Again, if the accelerator pump isn't giving it what it needs, that would answer the hard start (crank, crank, crank, not hot sart) issue.
I toss the carb issue into the equasion because if you don't know good from bad, you are at a loss for finding the problem.
I have been considering the distributor too because everthing seems to add up to a spark problem. Steve is on a fairly tight budget too, so I hate to go out and play hit-or miss with his money. The only thing worse than that is playing hit or miss with my money.
Use a vacuum pump to see if the vacuum advance canister is properly advancing and releasing the plate. If the diaphragm leaks or if the link is sticking, that can contribute to your problem.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
Thanks Jon. I had read that, it may have been, a few years ago. Let's fact it, I'm a readaholic. I became a readaholic at about 18 months of age--learned to ready by accident--and I have been a readaholic ever since.
Yes, unlike before the acc/pump replacment with no gas, it gives a shot of gas. The issue I look at is it that were a quad, it wouldn't be a stong enough shot of gas. I wish it had something to compare it against so I would know for sure.
Thanks Vicki. I knew that you would be able to come up with a tool source.
I'm still not ruling out spark/vacume as the cause, and I have just the vacume pump for the job. But I have found it wise to revisit areas, especailly when it doesn't require major overhauls and a few hunderd dollars thrown at it.
The thing with the vacume line is the way it's hooked up. It shares a fitting with the brake booster, and the fitting is about 3x too large for the line, and it's a major pita to hook back up.
It has to be something small. The best bet would be to pull the distributor so I can get a good eyeball on it. And it wouldn't hurt a thing to give the advance a good cleaning because it was hanging up; a little shot of wd doesn't qualify as cleaning up a sticking advance. We will also get some new vacume lines and look it over as to the best way to route the vacume lines.
As I recall from seeing Ashtray's car, a previous owner disconnected the ported vacuum switch circuit that is used on the 68/350. They rewired the vacuum lines without passing through this switch. I didn't pay much attention, but I think they buggered up the switch too.
Who knows if they rerouted the hoses to suitable places? Check to see if they make sense to you. This switch routed vacuum around depending on engine temperature. It's acting as though your stuck with late timing because this switch is missing. That will make the car drive like a stone.
I haven't been able to find a clear drawing for this anywhere. Maybe someone can post a clear photo? I'm sure I saw one somewhere, but I can't find it tonight.
I think with this thermostatic vacuum switch system ripped out, the factory distributor advance curves are out the window. You may get it working okay without this stuff by configuring it for the flow outlined in black for "off idle or cruise position, timing advanced". Where is the other side (the linkage side) of the distributor diaphram connected?
As long as it's Ashtray's money we're spending, Ames sells this vacuum switch for $37 and the hose kit for $56. Starting with the correct OEM configuration may be the best starting place.
You say the car developed hesitation. Did the problem start after a period of working okay, or is is something that was noticed after making timing adjustments? Was this hesitation after setting advance "to stock" with this wrong vacuum system in place? The factory procedure probably won't arrive at correct timing with stuff hooked wrong. Maybe it needs some more advance the way it's hooked up. Crank the advance up till she pings and back off a tad. Or disconnect and plug the hose to the rear port of the distributor advance can.
Well, just some ideas to kick around. If someone's put a single port distributor in, ignore what I've said.
Ashtray, I have a vague recollection of the switch being there but not connected up and its vacuum ports were damaged. I might be recalling a different car though. Take a look for it at near the upper radiator hose on the manifold and let us know what you see.
I finally found a clearer diagram of the vacuum lines. Imagine it being here
My thought is that if vacuum is being applied to the retard side of the distributor, you won't get the advance timing you need. Setting static timing by the manual won't take wrong vacuum connections into account. Somewhere along the way, you may have set per the book but the retard side vacuum throws that setting out the window.
In any case, I think Amervo is hot on the trail. One way or another, there is a lack of timing advance. This is very hard to check because you can't watch the timing mark while you drive.
Larry - how do you remember the vacuum line setup in my engine?! 
