Hey guys,
(65 f350 352) Ive got a timing situation. My truck never really ran great. Poor throttle response. I’d get bogging and backfires in low the low rpm range of gears 3rd and 4th. I also had pops and backfires when engine braking as well as between gears. I tried every combination under the sun on the mixture screws. I bought a rebuilt carb and swapped the points and coil to pertronix. Still wasn’t running or idling great. So I tried my hand at adjusting the timing with a light, tach gauge and vacuum gauge. The white chalk marks are the pointer and the V mark for 6 degrees before TDC (I think). The yellow line is where it was reading when I started. When I moved the chalk lines together to be 6 degrees , I could barely keep it running. I went through all the adjusting and could never get above 15 lbs of vacuum and it ran really rough. Inadvertently, I severely retarded the timing and to my surprise it purred like a kitten 18-19 lbs of vacuum. My first question is how does that happen? Did something slip internally and knock off the marks? Second I’m still getting the engine brake and between shift popping. Checked the plugs and they look to rich so I’ve been slowly leaning it out. I ran out of test drive time tonight. Am I headed in the right direction for that issue or could it be something else? Full discloser my muffler looks like a rusty bucket that was used for target practice.

 

Did you have the vacuum line to the distributor disconnected when you checked the timing? The dampner ring that the timing mark is on have been known to slip after years of use. The rubber that holds it to the pulley assembly rots and hardens, crack etc with age.

 

I did have the vacuum advance unhooked and plugged. I figure something must be off. Rubber for the marker makes sense.

 

Your picture doesn't show up well but I can't make out any timing marks on the balancer. This is a pic of a 65 352 I have. It is pretty rusty but the marks still show up. You need to lightly sand that balancer ring until you can make out the markings otherwise you're just shooting in the dark. Also make sure your vacuum advance is working. The symptoms you described in your first post point to a bad vacuum can or your advance plate is bad and needs replaced. On the Autolite distributors the advance plate rides on three little nylon rivets those rivets wear out, fall out, then your timing is all over the place.

 

This ole timer occasionally gets confused if timing becomes an issue at which time I tend to resort to the back yard mechanic approach in determining whether the timing marks are aligned. !st check to verify the plugs wires are are consistent with timing. I then remove plug #1 and place finger in the opening while the engine is turned over and once compression forces finger out of the opening I immediately stop and check the position of the rotor, should be pointed at #1, and then check the position of the timing mark, should be close; if not, then I can remove the distributor retainer bolt and lift the distributor out and rotate to the correct position that is aligned with the timing marks. I gently close the idle mixture needles screws then open approx 1 to 1.5 turns, once the engine is running I can fine tune from there.

I have a 64 Thunderbird 352/390 in my 65 and running between 10-12 degrees. Also have Electronic Ignition and found the only issue regarding tuning is I set the spark gap at around 45?
t? In addition, an adjustment in the idle mixture requires resetting the timing. lock when setting the timing.

 

I keep hearing and reading about the 45 gap. I’ll try that first. Ten thousand is a big jump when talking about 35 gap so maybe that’s a big part of the backfire and popping problems. Appreciate the advice.

 

Not sure if the Spark Gap on all Electronic Ignition Systems are same, Pertronix gap setting may be different than my DuraSpark ll ignition?

 

Plug gap with a Pertronix would be the same as points .032-.036. The gap between the pickup and the reluctor is important on the Pertronix and can be affected by a worn vacuum advance plate.

 

I have the pickup gap set at what pertronix recommended which I think was .30. I tested the vac advance yesterday. It held vacuum and the plates moved with the vacuum. I’m not sure that they moved appropriately. This is my first rodeo with this issue.

 

X2 on the plug gap, Pertronix doesn't change that, normal .035 is all you need.

 

Sounds like you are going in the right direction. Find those timing marks on the balancer and set the timing with them. Then if there is still a problem it should be easy to figure out. One thing to remember with these old Ford carbs with power valves is if you get a serious backfire it will blow out that diaphragm and your carb will go pig rich.

 

One other item to look for is timing chain slop. First find your TDC by removing #1 spark plug, bring the piston to TDC then use a piece of wire to touch the top of the piston to find true TDC because the balancer may have slipped, MARK your balancer there.
Now turn the crank CCW gently until it stops, and make a mark on the balancer again.
Now turn the crank CW gently until it stops, mark the balancer once more.
If you have more than 15 degrees movement in between the 2 marks, you will need to replace the timing chain and gears.
It's not a bad job on a FE engine but others can be more challenging.
You would think that after all the years that our trucks have been used nicely or other wise the timing set would have been changed at least once and the nylon gears have been long gone but you never know until you aes in there.
By the way 10 degrees slop is usually the limit on a timing set.