If It Went Any Slower I Be Stopped.....Help!

[1938 Coupe]

I was on my way to the upholster for a new headliner being installed. The v8 60 was running just great for the first 10 miles into the trip and keeping the speed around 55 mph. At first I noticed my speed started slowing down to 45 and then 35 and then 25 mph. I got off the freeway before someone rear ended me for going to slow. I was lucky enough to be able to take backroads and keep up with traffic. The motor idles fine and seems to run a little better with the choke slitty pulled out.
The gas tank is new, fuel line is new, fuel filters are new, rebuilt carb, electric and mechanical fuel pumps are new.
Is this a gas or electrical problem (points, timing, rotor, etc.)? The motor runs like it has a governor installed. I know the thrifty sixty doesn’t have a lot of power, but it should go faster than 25 mph???
Any ideas what may be going on?….Please no v8 60 jokes! I've heard them all.

[Scott H in Wheaton]

Acts like its getting choked, either not enough air coming in to the carb or not enough air going out the exhaust. Check for obstructions.

I feel if it was ignition or fuel related you would have sputtering, rough running, misfire.

[ford38v8]

It sounds like you do have fuel in the bowl, but that it is restricted at the main jets. Even though your fuel system is new including your filter, you could easily have had some crud pass up into the carburetor bowl. Take the top off and check for crud blocking the main jets.

[Phil Gillespie]

Check the linkage from throttle to plunger at bottom of carb. Had this come out on me the other day and experienced similar.
Phil
NZ

[V12Bill]

Some times a muffler will come apart on the inside or an exhaust pipe will delaminate and block the exhaust. You can hear the blockage as the exhaust struggles to exit the tail pipe. remove the muffler or loosen the pipes from the exhaust manifold and see if the power is restored. If spark or gas is restricted, there is usually some kind of miss in the engine.

[FortyNiner]

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I would start at the carb and work backward to the tank verifying the performance of each part. Don't assume anything. Your symptoms suggest a fuel delivery issue.

[funrunr]

I agree with most and start with the fuel, seems to be starving at continuous higher speeds. Most likely it will rev fine in the driveway, yet begin to starve after continuous speed. Do you have a fuel pressure gauge that you can watch? Also check and confirm none of your fuel lines are getting exposed to "HOT" surfaces. (exhaust or radiator hoses)

[Kurt in NJ]

The 60 that we had would slow down when it got hot, the spark got weaker as the coil warmed---even coils that worked on the 85 engine would slow it down when hot, eventually a remote mounted coil was installed, top speed went to over 75, and it didn't mind running 70, fuel mileage went up ---the richer mixture of some choke would keep it running longer when the spark was weak

You could take a plug wire off while running cold, see how much gap the spark can jump ---then go for a drive and check the spark as the car slows
also I found the best performance and fuel mileage by downshifting to 2nd at 40 when in hills, the 60 has no low end torque but it didn't mind being wound out when it was balanced to original specs ---

for a while I got good at roadside coil changes, every time it slowed down I would change out to a cold coil ---at the time I didn't know or it was bedore Skips coils, the remote mounted coil solved the long trip at highway speed problems---

[rotorwrench]

An excessively lean mixture will cause the engine to hickup through the carburetor. Pulling the choke can reduce the air coming in enough to enrichen the mixture to a point where it will still run. Exhaust blockage won't cause the hickup but the symtoms are similar. I agree with either exhaust system blockage or a fuel delivery blockage.

[Willit Stop]

If you have a vacuum gauge handy this might help.
http://www.secondchancegarage.com/public/186.cfm

[waterboychuck]

What type of gas cap do you have on the car? Is it vented? Remove the cap and take another run to see if you have any improvement. I also agree with the coil answer.

[39topless]

If you have a spare (one that you know works) condenser, I would change it out and see if that is your problem. I've had new condensers fail after 20 miles on them

[AnthonyG]

I know it's old news but, coil, condenser. Both will give this kind of symptom.

[1938 Coupe]

Lots of good ideas here. The coil I have now is mounted remotely so I'm not sure if it could be that. I will check everything else mentioned when I pickup the car.

[George/Maine]

On a 38 stock tank the gas line should go into the tank to 1/4 tank of less.
Your gas line could be above the gas level in tank.
Add some gas.

[1938 Coupe]

Originally Posted by 1938 Coupe

I was on my way to the upholster for a new headliner being installed. The v8 60 was running just great for the first 10 miles into the trip and keeping the speed around 55 mph. At first I noticed my speed started slowing down to 45 and then 35 and then 25 mph. I got off the freeway before someone rear ended me for going to slow. I was lucky enough to be able to take backroads and keep up with traffic. The motor idles fine and seems to run a little better with the choke slitty pulled out.
The gas tank is new, fuel line is new, fuel filters are new, rebuilt carb, electric and mechanical fuel pumps are new.
Is this a gas or electrical problem (points, timing, rotor, etc.)? The motor runs like it has a governor installed. I know the thrifty sixty doesn’t have a lot of power, but it should go faster than 25 mph???
Any ideas what may be going on?….Please no v8 60 jokes! I've heard them all.

I finally picked up the car from the upholster and it run like crap all the way home. I pulled off the air cleaner and checked the airway and everything was clear, but the motor wouldn't rev up when you gave it the gas. I put my hand over the carb as to choke it and then it made a popping noise and started running like a top. The motor revved up and had all the power a 60 could produce! Does anyone know what happened? Was there junk in the carb that was cleared by me putting my hand over the carb and chocking it?

[54vicky]

I think you probably dislodged dirt? what ever plugging jet.did the very thing a couple of times.by chocking you created a strong vacuum that forced the blockage through.

[tubman]

Sounds like you have it, to me!

[funrunr]

Great news, another pain in the arse resolved!

[ford38v8]

Originally Posted by ford38v8

It sounds like you do have fuel in the bowl, but that it is restricted at the main jets. Even though your fuel system is new including your filter, you could easily have had some crud pass up into the carburetor bowl. Take the top off and check for crud blocking the main jets.

You've dislodged the dirt blocking the jets, now follow up by inspecting the bowl. Where there was one piece of dirt, there will be more.