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Discussion Starter · #1 ·
I have a 55 with a 265 and powerglide. It runs fine at idle but will not accelerate at all. Wide open downhill it will run 42 mph. It acts like the timing will not advance properly. It will not crank when it is hot either. It sat for almost 3 yrs beforeIi got it. It has new plugs, clean tank, fuel filter before and after pump. Cleaned the carb and also put on another carb (rebuilt but not by me). Runs about the same with both carbs. What could cause this? Still has points in dist.
 

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I have a 55 with a 265 and powerglide. It runs fine at idle but will not accelerate at all. Wide open downhill it will run 42 mph. It acts like the timing will not advance properly. It will not crank when it is hot either. It sat for almost 3 yrs beforeIi got it. It has new plugs, clean tank, fuel filter before and after pump. Cleaned the carb and also put on another carb (rebuilt but not by me). Runs about the same with both carbs. What could cause this? Still has points in dist.
Your problem could be a variety of things. Try to eliminate them one at a time. Sounds like you've already eliminated the Carb.

To answer your question, if you hadn't already done so, to see if your vacuum advance is working, simply detach the vacuum hose from your distributor, start your engine and see if anything has changed. If it runs same, then I'd suspect it has to do with the advance. If you do see a change, then it may be working okay.

If you're still running points, make sure they are gapped properly.

Best of Luck with it! BDR...:cool:
 

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Do you know if the distributor was rebuilt at the time of the rest of the motor. If not or you are not sure, it may be that the distributor is gummed up and not functioning properly, including the vacuum advance. You might try having the unit redone. I have used Bubba's Hot Rod Shop for my 235 distributor rebuilds. Very fair price and excellent work. You might also check your running vacuum to see if you have enough vacuum to actually operate the can, in addition to checking to see that the diaphragm in the advance itself is not shot
 

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I have a 55 with a 265 and powerglide. It runs fine at idle but will not accelerate at all. Wide open downhill it will run 42 mph. It acts like the timing will not advance properly. It will not crank when it is hot either. It sat for almost 3 yrs beforeIi got it. It has new plugs, clean tank, fuel filter before and after pump. Cleaned the carb and also put on another carb (rebuilt but not by me). Runs about the same with both carbs. What could cause this? Still has points in dist.

Does it miss or just bog down> :anim_25:
:gba:
bowtie-trifive
 

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3 psi fuel pressure should get you to more than 42 mph, especially if the pedal isn't on the floor.

The vacuum advance by itself won't cause your problem either.

I would do three things to get started.
1. Make sure you have all the plug wires connected and connected in the right firing order.
2. Pull all the spark plugs and see if any are fouled with oil or fuel.
3. Check the timing with a timing light. You may need to clean up the timing marks on the balancer and timing tab.

There's a bunch of things that could be wrong, and you may have more than one thing wrong. I am assuming that you have fresh fuel.
 

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Hey,,,,554Dr150,, Try this quickie,,
Hook up a timing light to #1 spark plug,, start engine and let it idle.
Disconnect vacuum hose at vacuum advance while pointing timing light at harmonic balancer. If Vacuum advance is working, you will see the light change position on balancer.
You can also wedge the "window" open on distributor and actually see the advance mechanism move when you disconnect the vacuum hose.
Also, hold vacuum hose to your skin while engine is running to make sure you do have vacuum at the hose. the tap could be plugged with exhaust buildup. Hope this helps. :flag6:
 

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Hello 554dr150,

While idling, pull off the hose to the vac adv. you should hear an rpm change if you have enough vacuum at idle. A vac. gauge is best but your finger should stick to the hose at idle or maybe just a bit of manual throttle.
This goes into the questions about how much vacuum is supposed to be on that hose at idle. 15 in hg is working for me.

You say it won't crank when hot, crank as in starter won't turn the motor over or crank as in it won't start?

When idling, if you manually throttle up, do the rpm's increase nicely or does it just bog down and run crappy? Curious if the power problem is only while on the road?

What is your idle rpm when it is running good? Good luck.
 

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Check that distributor shaft bushing, make sure its not wobbling. That can do all sorts of things.
 

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Discussion Starter · #19 ·
It spins over fine when hot but will not start. When you throttle up, it bogs. Not only when on road but sitting too. If you increase throttle slowly it will rev higher than it you increase it fast.
 

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Hmmmm how's your carb's accelerator pump? With the air cleaner removed open the choke butterfly and snap the throttle open while looking down the carb. You should see a stream of gas pumped into the carb as you move the throttle. If not you have a problem with the pump.

Don
 
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