Nearly Dies Going Uphill

[MercuryMarc]

The old Holley 1940 (manual choke) works fine, but when I went up a big hill the car stumbled, backfired, missed, and nearly died. If I backed off the accelerator it worked OK. I had the timing set at 12 degrees, so I reduced it to 8 degrees and it is about the same (maybe a little better?).

Although my old Holley 1940 (Auto Choke, leaky float bowl) took forever to start, it went up hills fine.

Any thoughts? I am thinking vacuum leak.

Marc in SF
63 Comet Ratop
69 200/C4
Dual Cupholders
http://mercurycomet.net

 

[Anonymous]

sounds like accelrator pump on carb. mine did that

 

[BIGREDRASA]

Dirty fuel filter or weak fuel pump. Low float setting, or maybe too high.

 

[MercuryMarc]

Thanks-
the fuel pump is new, and the fuel filter is easy enough to replace. If that does not work, then I can reset the float. I think the accelerator pump is OK since I see a large spray when I advance the throttle linkage.

Marc in SF
63 Comet Ragtop
69 200/C4
Dual Cupholders
http://mercurycomet.net

 

[CobraSix]

My guess is float as well.

Slade

 

[MercuryMarc]

I am thinking float, too, since the problem is only present if I am 1/2 way up the hill and going over 30 mph. So for now I am trying to avoid hills (which is tricky in San Francisco!!!).

Thanks again for all the advice-


Marc in SF
63 Comet Ragtop
69 200/C4
Dual Cupholders
http://mercurycomet.net

 

[BIGREDRASA]

OK, I'm dying to find out what you found out!

 

[Ronn]

It may be the orientation of the float, does it point front to back or sideways? Are the jets located real close to the bottom of bowl and are they located on the front, back or side of car? My RBS will die out if I take a hard turn to the right or go up a serious hill at full tilt. It's just that fuel is not getting to the jets, all the fuel in the bowl is being forced to the sides of the bowl from g force there fore robbing the jets of, fuel. I raised the float level a little bit and I don't have the problem as bad. Could be too that not enough fuel pressure will run the float bowl low on fuel under hard driving. First thing I would try is raise the float level, if it don't work, put it back where it was and go to next possibility.

 

[Lazy JW]

Does it stumble on flat ground when you mash on the throttle in high gear? If so, you may have ignition problems, such as bad wires, plugs. If you can lug it down and give it full throttle without bogging then the ignition is good.
Joe

 

[MercuryMarc]

Thanks for all the continued support!
I changed the plugs, air filter, moved the timing back from 12 to 10 degrees, put in a new fuel filter, and checked the ignition wires. The connection between the center distributor wire and the coil was cracked and corroded at the coil terminal. I cleaned this up and replaced the connector with a spare I had lying around, and added dielectric grease. Just went up that big hill- no problems!!!
I believe my car may have "multifactorial" issues - that is to say problems arrising from more than one source. I still believe I could also have a float problem, but I am haven't takes the carb off yet to check or adjust.
Again, thanks to all the wonderful folks who make this forum so great.
Happy Holidays to all.
Marc in SF
63 Comet Ragtop
69 200/C4
Dual Cupholders
http://mercurycomet.net

 

[BIGREDRASA]

The bad coil contact makes sense, since going uphill would demand the greatest amount of effort from all components.
Happy motoring!

 

[Lazy JW]

The bad coil contact makes sense, since going uphill would demand the greatest amount of effort from all components.
Happy motoring!

Yup. When it bogs at full throttle under load and smooths out when you let off it is a pretty good clue that the ignition is giving up. High powered ignitions are actually worse in a case like this because all that spark energy has to go somewhere and it goes to ground via the easiest route. And whenever that is someplace other than the spark plug.........
Joe

 

[MercuryMarc]

Well, even after the coil wire was properly connected, the stumbling 1/2 way up big hills continued if I was going over 35 mph. I rebuilt the carb twice (the old Holley 1940) and after blowing out all the passages the second time around, the car now works great! I have been up and that monster hill going FAST and no hesitation.
Oh yeah - did I mention I found the problem? The 2 inch section of fuel line from the fulter to the carb had a CHUNK OF FOAM in it!!! Silly me, but even though I replaced the filter, I still used that old fuel line. It had that same piece of line when I was using both old and new carbs.
So after I added a new fuel filter, rebuilt carb, new fuel fump, and new air filter, I finally solved the mystery!! It only took 4 months.
Here is a picture of that little Gremlin...

Thanks for all the advice and infinite patience with us novices!!
Marc in SF
63 Comet Ragtop
69 200/C4 (fixin' up the 78 200 for transplant)
http://mercurycomet.net

 

[BIGREDRASA]

I used to tell my kids, "If you can't figure out the problem, and need to start replacing parts, change the cheapest first!"
Glad you solved it.

 

[Anonymous]

Mystery solved...a good story along the way.