High Altitude Adjustments, Car Bucks/Jerks and Shakes

Hi All,

Recently picked up a 1963 Falcon with a 1965 170, Autolite 1100 carb and 3 speed manual. It now lives at 6,500 feet and I've just got it running again after some neglect from the previous owner. I can drive it around town OK but need help getting it fine tuned. Cruising down a relatively flat road it seemingly runs great. Idles great (600rpm) but any bit of load required its bogs down, gets jerky, bucks a bit, car shakes etc.

I reduced the main jet 2 sizes (#61 was in it, now running #59) and the idle mixture screw is tuned almost all the way in (this is where smoothest idle was).

What has been done:
New plugs
Petronix ignition
Petronix coil (has constant 12v)
Carb has been rebuilt and thoroughly cleaned
Accelerator pump pin has been moved to the "above 5,000ft" position
New gas tank
New fuel lines
New vacuum advance canister
Completely new cooling system (pump, radiator, thermostat and hoses)
Still has original fuel pump
Does not appear to have a vacuum leak.

Ive attached a picture of the plugs after driving a ~45mph sustained for 30min, #2 has not been cleaned, that's how it came out.

First welcome aboard. I don't like the looks of #1 plug, it looks fouled.
What brand of plug wires are you using??
If you move the accelerator pump to the other position, does that correct the condition.
If not i would look at the electrical side.
Did you install a new cap & rotor? Are they new plug wires?
Ohm #1 plug wire & what is your reading?
Install a new plug in #1 or swap it to another cylinder & see if it cleans up.
Advise from there.

Plug wires do not have an branding and I didn't change them. Thinking I'll order the Petronix ones so everything matches and works together.

Cap and Rotor were not replaced either but both look new and seem in good shape.

I think plug wire #1 is bad, the resistance indicated below is "blinking" this value. As in, it goes form OL to 4.1k ohms to OL to 4.1k ohms in almost perfect cadence. Tried twisting the wire around and no change.

Resistance of plug wire:
#1 is 4.1 kohms (blinking)
#2 is 4.3 kohms
#3 is 5.04 kohms
#4 is 6.5 kohms
#5 is 8.4 kohms
#6 is 9.3 kohms

I'll swap the accelerator pump pin and see what happens, I never ran it the other way so no comparison.

Looks like maybe a set of Champion Plugs. What kind of results did you get on a compression test?

I don't have the tools for a compression test at the moment so that hasn't been done. Reached out to a buddy that should have it and will get it done.

They are NGK plugs

Hi, an easy test for these old engines is to warm it up and let it idle and remove 1 plug wire at a time. If the engine shakes and gets rough it tells you that cylinder is working. If there is no change the cylinder is not working and you have to find out why.
Also a good time to double check the firing order.
Get the Ford Falcon Performance Handbook from Vintage Inline to get the most out of your Ford Six.
Good luck

2X ^^^^ the above, while waiting for Matt's delivery ck above 'tech archive' by clickin on the blue box w/crossed screwdriver/wrench.
U must ID what U have 1st. (Its 50 yrs old right). Look to the "LOM/SCV feedback system" (on the index of that archive) to see if ur set there...
2 need to match.
Who knows what OP (& how many others of them?) did w/to the vehicle...

Also, next/last: ignition tune comes B4 carb. Got that set?, go to carb nxt...
Lets C what else may B missed...

Thanks all, Ill have some time Monday to go through these things.

To add to my notes above and help with overall information provided:

• Carb is a SCV carb with SCV in place and matching LOM distributor
  Timing is set at 9-10 degrees, hard to tell with the old marks and my old timing light
  I swapped around plugs 1-3 to see if they change after the next drive
  Firing order is verified correct
  I am replacing the vacuum line from the carb to the dist to rule this out
  I adjusted all the wires so contacts are tight on both ends and put some wire separators between wires. Boots are fully covering each contact.
  When plug wire is pulled during idle, there is no dramatic change to idle when any one is pulled

Thanks for help all, Ill go through each comment and will come back on Monday

Quick report back.

I moved the accelerator pump pin back to the lower hole and it made a noticeable improvement. It still bucks under certain load circumstances but the movement of the pin helped without a doubt.

I am picking up some .040 gap plugs today and will swap them, the plugs that are in the car now are .034. Seems like the consensus is that the Pertronix stuff likes a bigger gap.

After those are installed and I drive it a bit I'll see if it likes a few more degrees of advancement.

Yes with a Pertonix, plus their good coil and wires .045 to .050 gap works well. You might also add 2 more degrees of base timing too, reset carb idle mixture to lean best idle, and then reset the curb idle RPM. Good luck

Thanks, I will knock all of that out too.

Should I jump up to a .045 plug? Sounded like a .005 increase was it

Yes go to .045 as the minimum

Did you get a quality set of spark plug wires that are spiral wound??

wsa111, I ordered the Pertronix wires to go with the Pertronix coil and electronic ignition. The set should be here Thursday.

More notes:
I installed Autolite 46 plugs today with a .044 gap. Seems to start quicker but there is now a slight bucking while cruising.

There is still also slight bucking under load going up a hill.

I'll continue to play with it, seems like I have a little more adjust-ability in the idle mixture screw now.

I played with the choke while it was bucking and it appears to smooth out with a small amount of choke applied.

To add to it... the tranny is now whining at idle

If you need to add some choke to smooth it out then your too lean, you might want to jet it up one or two sizes.

make sure not to use synthetic but top off w/90 weight.
Check ur level as a 1st step, if dwn use 75-90w to top up.
Did U ID it yet, just cuz it's a '63 (50 yrs old, no known history ) & 3 speed duz not mean it's what wuz in there oe.
Is it dripping?
Duz it shift OK?
(new thread time?)

Bubba, I have both 1 an 2 sizes bigger. Ill start with 1 size and see how it goes.

Chad, I haven't IDd exact year on the trany as its caked in crud, the motor is a 1965 170. The tranny is certainly a 2.77 top loader based on the cover. Fluids were changed, I stopped filling it when It started coming out of the top hole. I used 80-95w as that's the only non synthetic stuff Napa had, it took about 1.5qts which seems low based on my research. There is a bit of moisture on the external linkages. I am going to adjust the clutch and will make a new thread if needed. That was mostly a "to add it the issues" comment

I am going to keep updating this till its running well. Its my biggest frustration when I find an old thread with a bit of helpful info but OP doesn't take it to the end and give a solution.

That's a good plan on the jet going up one size at a time. On the trans whining at idel that sounds like you will soon need to put in a new input shaft bearing to fix that. Best of luck on the tuning.

Hi, it is also possible the whirring noise is the throw out bearing. You usually can feel that with your foot on the clutch pedal. A throw out bearing noise can change as you push on the clutch. Good luck

Just curious, when was the last time you changed your fuel filter?

I see that you changed other fuel related parts, and you probably changed that as well - but it is worth looking at. A clogged filter can cause intermittent bucking.