Engine sputtering at about 65

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Ever check the mechanical advance to see if it is free?
 
i wouldn't change the distributor unless it's faulty, or a points dist.

is it electronic? if so maybe just put an MSD streetfire ignition box on it.

if the motor has a stock camshaft in it then, the factory dist timing is fine. which will be about 28-30* mechanical advance most likely, so you set the initial timing around 8* advanced, adjust your idle mix on the carb and set idle speed. on to the next thing...
 
cookietruck said:
i wouldn't change the distributor unless it's faulty, or a points dist.

is it electronic? if so maybe just put an MSD streetfire ignition box on it.

if the motor has a stock camshaft in it then, the factory dist timing is fine. which will be about 28-30* mechanical advance most likely, so you set the initial timing around 8* advanced, adjust your idle mix on the carb and set idle speed. on to the next thing...
Click to expand...

The timing does seem to be part of the issue, and because with a moderate pull the motor seems to do ok, but asking for more out of it, she sputters, I thought timing, specifically the advance. My thought was maybe this distributor is just not able to advance enough due to age or just being worn out. If it's just a new set of springs then maybe I can breathe new life into it.

The reason I thought HEI was two fold though, one, why bother trying to bandaid an ancient distributor and two, with an HEI, I can get rid of a whole bunch of clutter from the engine compartment which obviously needs help lol.

It's not electronic, no.
 
Your timing can be 5 degrees late and it won't cause a sputter. Even 10*, and maybe more. I know because I have a dash-mounted, dial-back timing device with a working range of 15 degrees, and I test these things, cuz I'm a curious guy.
>I'd be more concerned that it had too much timing.And I'd be most concerned that the Vcan had died. But,if the Vcan diaphragm works, and the timing is at least close,think about it; as long as the coil can light the fire at the sparkplug tip,and you have already proven that it can by driving thru the problem;forget about ignition; at least for now.
>If it's related to throttle input,as you describe, it's most likely to be a mixture issue.IMO you have exactly 3 possibilities, a cold-running engine, the pumpshot,or the transition circuit.
>as to a cold engine
Cold engines require extra fuel on account of not all the fuel gets burned, instead sticking to cold surfaces, then tearing off in sheets, and passing through the engine,some of it unburned. The hotter you can run them the less compensation they require. Of course there's a limit to how hot you can go. I run mine at a minimum 205*F.
>As to the pumpshot;
Figure out how far your throttle is open at cruising speed. This may require some ingenuity on your part. Then stop the car, and stop the engine. Now open the carb to that amount, stare down the primaries, looking with a flashlite, and ever so gently open the throttles just like you do with the footfeeder; There better be a small amount of fuel delivered from the pump-nozzles, and it needs to not be a dribble.
>As to the transitions
Your carb has multiple transition circuits.
There are;the Idle to idle plus transfers; that plus the mains; and that plus the M-rods.And they are all air-flow driven,and/or vacuum controlled.
In your case,per your description, the primary suspect after the temp and accelerator pump,is the transfer to main transition, at part-throttle tip-in.
At 65mph, the M-rods should be stuck down hard,by vacuum. Your butterfly valves may or may not be at the top of the transfer slots, depending on the load being presented to the engine, and the throttle-opening being used to achieve the power to achieve the speed.The vcan should be at max timing, and the total all-source timing should be more than 40*@2200. Firing on all cylinders this can easily done on the transfers, by even a lazy SBM.
Ok so, you're cruising at 65, and start rolling into the throttle:
The very immediate thing that happens is that the manifold vacuum drops. Immediately. Simultaneously the Vcan may start dropping timing, but doesn't necessarily have to yet . Also simultaneously..... The accelerator-pump should deliver a bit of fuel, in response to the drop in signal at the T-slots.
If you then stop the throttle tip-in, the pump shot ceases and the engine vacuum stabilizes, bringing the Vcan back on line, if it relaxed. At the new higher cruise rpm, the D should be supplying a new slightly higher amount of centrifugal timing, and everything returns to normal.
But if you continue increasing throttle opening, eventually the T-slots get to max flow, and by this time your main boosters need be on line. But the boosters better be delivering pretty small droplets of fuel, cuz the big ones may not burn, and go straight out the tailpipe. Or, they may drop into the bottom of the manifold and stick there like raindrops do on your windshield, slowly creeping down the runners. Eventually they rip off and plow into the cylinder, and most probably never finish burning in the chamber.These may even be the cause of your sputter, but I don't think so.
So the trick is for the boosters to deliver those small combustible droplets. The carb does this by mixing air into the fuel, BEFORE it gets to the nozzles, inside something called the emulsion tubes. I'm suspecting a problem in these, or in the transition to these, iF the problem cannot be blamed on the temp or the pump-shot.
>As to the transition to power
The power transition, in the case of a metering rod carb, is controlled by the step-up rods and more specifically the springs under them........which have to be synchronized to the manifold vacuum.
...And that leads to suspecting manifold vacuum, which leads straight back to the basics,
the compression,
the idle-vacuum,
and maybe the valve springs, or lash.
Then the fuel, the fuel level, the fuelpump output,finally the carb.
You can keep on working on the carb, or jump in anywhere you like, but I doubt you'll get to the bottom of it in a reasonable period of time. I'm old, and I learned the value of basics many many years ago,spring of 1968.

There's only one way IMO, that it could be timing related, and that would be if it was severely over advanced or severely late, both of which lead to vacuum issues, and thus step-up issues, and thus transition issues.And you would see that unusual timing on the vacuum gauge
In any case
We're in your corner.
 
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I agree ^, I don't think timing is the problem.

Did you put an 8.5 or 9.5" hg power valve in the carb?

just to the be sure, the distributor has only a single wire? not two wires going to a black rectangular plug??
 
AJ/FormS said:
Your timing can be 5 degrees late and it won't cause a sputter. Even 10*, and maybe more. I know because I have a dash-mounted, dial-back timing device with a working range of 15 degrees.If the timing is at least close,think about it; as long as the coil can light the fire at the sparkplug tip,
and you have already proven that it can by driving thru the problem;forget about ignition.
If it's related to throttle input, it's a mixture issue.IMO you have exactly 2 possibilities, the transition circuit, or the pumpshot.
The transition, in the case of a metering rod carb, is controlled by the step-up rods and more specifically the springs under them........which have to be synchronized to the manifold vacuum.
...And that leads to suspecting manifold vacuum, which leads straight back to the basics, testing the compression,the idle-vacuum,and maybe the valve springs, or lash.Then the fuel, the fuel level,the fuelpump output,finally the carb.You can keep on working on the carb, or jump in anywhere you like, but I doubt you'll get to the bottom of it in a reasonable period of time. I'm old, and I learned the value of basics many many years ago, about spring of 1968.

There's only one way IMO, that it could be timing related, and that would be if it was severely over advanced or severely late, both of which lead to vacuum issues, and thus step-up issues, and thus transition issues.
In any case
We're in your corner.
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Wow that's a lot to absorb. So the new carb is installed, I made sure there were no vacuum leaks with the carb cleaner test. I set the idle set screws at 1.5 turns out and the idle speed to what I feel is a pretty solid resting idle. It's stronger through acceleration but still will wants to sputter up around 65, so the underlying cause is still here. I'm not upset about purchasing the carb since that secondary shaft was absolutely gone and I didn't want to mess with drilling and pressing new bushings in.

Will this eliminate fuel as the issue all the way from the carb to the start of the steel supply line that runs back to the gas tank, being that it's new fuel hose, new carb, fuel pump and filter?

If the timing can't be an issue, I'll look at the vacuum levels next. It used to be she idled at a perfect 20 psi but I haven't put the tester on it since the new carb is in place. I might actually buy enough vacuum line to run the gauge back into the car and drive it that way to see what it does when driving.
 
cookietruck said:
I agree ^, I don't think timing is the problem.

Did you put an 8.5 or 9.5" hg power valve in the carb?

just to the be sure, the distributor has only a single wire? not two wires going to a black rectangular plug??
Click to expand...

Its a new carb, so whatever the stock power valve is in it now.

The distributor has a single wire going to the coil, the 8 plug wires obviously, and what looks like 2 tiny gauge sensor wires off the side of the cap.
 
cookietruck said:
I agree ^, I don't think timing is the problem.

Did you put an 8.5 or 9.5" hg power valve in the carb?

just to the be sure, the distributor has only a single wire? not two wires going to a black rectangular plug??
Click to expand...

This is the closest shot I have of the distributor. I popped the cap on the distributor and the rotor has a touch of carbon built up on it, wasn't sure if that's normal or not.

Distributor sensor wire.jpg
 
did you ever do the fuel volume test, if no surging in 1st gear or 2nd gear at wot its a fuel delivery problem
 
halifaxhops said:
Like throwing parts at it, man I wish I was Better off. Back read once and a while and follow the advice. I am out!
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I'm not sure what you're getting at here, but thanks for the snark filled comment, it's highly constructive.

Someone asked about fuel flow, I tested it, was not up to the quart a minute, I replaced the fuel pump.

If you're insinuating that I should have yanked the tank, cleaned, and/or replaced it, sorry that's a huge job that I'm not ready to do right now, especially after the new fuel pump gave me acceptable fuel pump flow when it hadn't before.

Replacing an old electronic distributor (that has a sketchy history) with a new HEI version is not "throwing parts at it", it's replacing old hardware with newer more effective hardware and getting rid of a coil and wire running through my engine compartment and something that isn't that costly, to boot.

If you're "out" then fine, thanks for your thoughts, but lose the snarky attitude if you're going to continue to try and offer helpful advice, because that's not what I (or most people) came here for.

This is my driver and I'm not sitting on a mountain of cash. It's reliable enough to get me to work but needs a bunch of things that I need to prioritize and be able to fit in along with my other "real life" responsibilities. If I can't do 75-80 on the interstate it's not the worst thing in the world and my insurance will stay low. I need to be able to do this in small manageable chunks, sorry if you think I should tackle something in a different order but that's not the only advice I got in this list and I've listened to all of it, not just yours.
 
I am truly out of line on that I just see so many people just waiting for a magic troubleshooting procedure and skip steps it is frustraighting to see. Seriously man I was out of line.
 
halifaxhops said:
I am truly out of line on that I just see so many people just waiting for a magic troubleshooting procedure and skip steps it is frustraighting to see. Seriously man I was out of line.
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All good, I've got thick skin and realize I'm very inexperienced compared to many on these forums. I like being able to be able to bounce ideas off a large group of people with different experience, especially being fairly new at this. I know enough to be dangerous as the saying goes.

And the gas tank for sure is something that I've got on the short list of things to do, no question. If nothing else for the fact that I have no fuel gauge and need to be able to go more than 2 days without filling up for fear of running out of gas. The gauge issue could be electrical at the dash or it could also very well being the sending unit itself and since the tank will come out anyways, a new sending unit is in order to go along with that.
 
Save the old locking ring the new ones do not seal properly, the gasket is ok the ring is not.
 
KitCarlson said:
The wiring of the plug wires is a mess. Have you checked for correct firing order?
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Unfortunately all of the wiring in this car is a mess. Also unfortunately I bought it this was so I have zero idea what corners were cut and how jacked up it fully is. I'm guessing that I wouldn't get it running half way decently if the firing order were out but I'll have a look and make sure.
 
Sending units are a crap shoot, either they are good or not, when it is out check it with a ohm meter before buying one I believe it is 24-75 ohms full travel. Nos is the best but serious $$$$ if you can find one. I got lucky I found one in a parts store of all places in mine. There is a few threads on them with recommendations just do a search. There are also a bunch of troubleshooting threads on them do it before you order anything can be something really simple like no ground strap on the sending unit to the frame.
 
halifaxhops said:
Sending units are a crap shoot, either they are good or not, when it is out check it with a ohm meter before buying one I believe it is 24-75 ohms full travel. Nos is the best but serious $$$$ if you can find one. I got lucky I found one in a parts store of all places in mine. There is a few threads on them with recommendations just do a search. There are also a bunch of troubleshooting threads on them do it before you order anything can be something really simple like no ground strap on the sending unit to the frame.
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Will do. Thanks.
 
halifaxhops said:
Any other gauges not working?, not reading back.
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Pretty much everything on the dash has screwed the pooch. Speedo cable's all whacked, no dashboard lights, no fuel gauge, battery/alt gauge is reading but don't think it's accurate. I have an aftermarket set of 3 mechanical gauges, oil pressure is the only one reading anything.

Like I said before, electrical in this car is a HUGE project and probably one where I will literally have to rewire the whole thing either at once or in stages. I actually found an inline fuse wrapped in aluminum foil (between the battery and through the firewall feeding something inside the car) by total luck, I happened to wiggle the wire and heard it shorting, I'm lucky the whole damn car hadn't gone up in flames. I replaced that with the appropriate fuse and the newer flat blade style fuses and re-ran that line. It still freaks me out.

The previous owner has added electric seats from a pickup and a heavy duty after market radio, my guess is they boogered up **** connecting those things
 
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