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Discussion Starter #1
Start here for some background. Skip to paragraph 4 for the real question. Let's get this out of the way. I'm a car noob. I was blessed enough to get a 1966 Mustang from my grandpa when I was 2 years old. I'm now 18, the car is with me and is my daily driver.

The car has never run 100% right since I brought it home from sitting in a garage for 10 years when I was 14.

I have taken it to multiple places including a vintage Mustang specialty shop and none of them have gotten it running reliably.

1966 200ci i6 w/ C4 3 speed auto tranny. In a nutshell, I bought an external tachometer and timing light to try and verify that the engine was running at factory spec RPM and timing (Though I did use a Chilton manual to get those spec numbers). According to that, timing should be at 12° before top dead center and it should idle at 525RPM (I have no A/C unit).

Where I am confused is verifying the timing using the light. My gun is a Cen-Tech Xenon and has a dial on the back labled Advance Degrees and goes from 0-60. The booklet that came with it said leave the dial at 0. Am I supposed to do that or turn it to 12 since my timing is supposed to be 12B TDC?
 

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Look at the balancer on the front of the engine. Do the timing marks have one labeled 12 degrees? Or maybe one is marked 10 and some smaller marks are adjacent and you can figure out which one is 12.
If so. Set the knob to zero. Point the flash at the pointer and the 12 mark should line up with the pointer.
Vacuum advance hose should be removed and blocked to prevent any chance of a vacuum leak.

The dial knob allows you to check things like the total mechanical and vacuum advance. The amount of advance is greater than the marks on the balancer. So the timing light electrically shifts the timing of the flash so the flash puts the 0 mark back in line with the pointer.
 

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Asm109, pretty much, nailed the use of a Dial Back. I have one too and like it a bunch.
Other items to check:
1. Use a Vac gauge to check the over all condition of the engine? (report your findings)
2. Can be used to adjust the idle mix screws on the carb?
3. Check the points setting (if it needs adjusting, do this before setting the timing)
4. Check condition of the Plugs and wires

Chiltons are "OK(?), but, a year specific Mustang shop manual is much better. NPD is a good source.
 

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Discussion Starter #5
Thanks. When I had the dial set to zero and rotated the distributor to put the mark at 12 degrees, I then hooked up an RPM gauge and adjusted the idle speed screw until it hit 525RPM, which is claimed spec. I then adjusted the mixture screw until it sounded smooth and consistent. After that I took it for a spin and that was one rough ride. It wouldn't pick up speed and the car was shaking like it was in an earthquake. That was what made me think the dial needed to be set to 12. Now that that's clarified, I guess there's another problem. You suggested checking the vacuum, which I guess I'll do next. Recently my transmission has been shifting at higher speeds than usual. 1st-2nd was formerly at ~15-20MPH, now violently jerks into 2nd at 30MPH. 2nd-3rd was formerly ~40MPH, now 55-60. The owner of a local auto trans shop said that could be a vacuum issue.
 

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Discussion Starter #6
I'm assuming this is supposed to be a link. It's not working, so please post the link again.

May I also suggest that you google how to use a timing light

Harry Z
No mistake, I just meant begin reading at the first paragraph if you wanted the full story and to skip ahead otherwise.
 

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Discussion Starter #9
I also have no clue where to find what my fast idle RPM is supposed to be which is also an issue. Currently sounds lower than 525 which is supposed to be the warm idle. Needless to say, it's making warming up the engine a lengthy process in the morning for someone who has to get to work/community college.
 

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Where are you located. Maybe someone in here can recommend a good shop to help your out or even lend a hand themselves if you are close.


Also update your profile it helps people with suggestions like this. I'm somewhat of a car noob myself and there are tons of people here with oodles of knowledge. They hepled me countless times. Kenash is correct, order a workshop manual from NPD. I can't tell yo how many times i have referred back to it!
 

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The fast idle should be when the choke is on. So, when you start the car when the car is cold you stomp the pedal to the floor once and that turns on the choke. It closes the plate at the top of the carb and lets in less air for the same amount of gas so it runs faster. Eventually it warms up and opens back up as the spring in the big black round cover stretches back out.

You should probably check that your choke is working. When the car is cold push the gas pedal to the floor, then get out, take the air cleaner off and see if that plate on the top of the carb is almost closed. If it's not (and it's not like 90 degrees outside) then you probably need to adjust the choke to get your fast idle working.
 

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Discussion Starter #12
Asm109, pretty much, nailed the use of a Dial Back. I have one too and like it a bunch.
Other items to check:
1. Use a Vac gauge to check the over all condition of the engine? (report your findings)
2. Can be used to adjust the idle mix screws on the carb?
3. Check the points setting (if it needs adjusting, do this before setting the timing)
4. Check condition of the Plugs and wires

Chiltons are "OK(?), but, a year specific Mustang shop manual is much better. NPD is a good source.
Got a vacuum gauge, it tested fine. (~19 inches of Mercury)
Points were converted to electronic ignition.
Wires are in good condition.
I own a spark plug gapping tool but no socket to remove them yet.

Like I said, I correctly set the timing the first go round by using the light with the dial set to zero and rotating the distributor until pulley was reading 12BTDC. Set the idle screw until RPM hit 525, adjusted the mixture until it idled consistently and smoothly, took it for a spin and the car hated the entire drive. No power to accelerate, the car was rattling hard like the panels were all gonna fall off lol. So the car seems to hate factory spec timing. Idk what to do about that, but I'm bullheaded and would rather not take it to a mechanic if I can fix it myself. It doesn't help that I like learning too, so again, a mechanic won't allow me to learn for myself.
 

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Adjust your timing using the vacuum gauge. Turn the distributor until you achieve the highest steady vacuum reading. You can also turn the distributor until you reach the highest RPM and then stop or back it off a little. NEVER trust the timing mark on the harmonic balancer on these old cars unless you just replaced it. If adjusting the timing does not help, increase the size of the main jet in the carb. I use a size 69 in my 200 6.
 

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I'm no mechanic, but I can say that I've read on this forum many times that the factory timing setting is too retarded. The experts here say advancing to ~15 or 18 degrees is better. I think @Fitch is saying the same thing regarding timing by vacuum and not so much by the balancer.

It's easy to give it a shot and see if things improve.
 

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My project stumbled badly when set under 15. I'm running more like 18 at idle. I ended up setting the max timing with vacuum disconnected to 35 which put my idle advance to about 17+. Runs much more crisp off idle once i adjusted the accel pump and idle mixture screws and got the timing where it is.
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Every engine is different, dependent of any mods wild or mild. If your engine runs "good" with 15-18º, so be it. As long as it's doesn't ping under load. There are so many variables........
 

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Discussion Starter #17
I'm no mechanic, but I can say that I've read on this forum many times that the factory timing setting is too retarded. The experts here say advancing to ~15 or 18 degrees is better. I think @Fitch is saying the same thing regarding timing by vacuum and not so much by the balancer.

It's easy to give it a shot and see if things improve.
Then I guess I'm all set in terms of timing and idle. Just need to figure out why I'm getting low oil pressure when at a stoplight after the engine has been running for a half hour or so. And figure out why the transmission is shifting so high.
 

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Then I guess I'm all set in terms of timing and idle. Just need to figure out why I'm getting low oil pressure when at a stoplight after the engine has been running for a half hour or so. And figure out why the transmission is shifting so high.

Shifting could be as simple as backing out the screw in the vacuum modulator....or not. I'd start with a full turn and see if you notice a difference.
 

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"Why I'm getting low oil pressure when at a stoplight............"

This is very typical for an engine at idle, the OP can read 20-25 PSI. What you need to worry about,.....if it does not increase to 35-45 PSI (depending on the age of the engine) then, you have a problem.
 

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Discussion Starter #20
"Why I'm getting low oil pressure when at a stoplight............"
It doesn't just rest at low. The needle completely bottoms out. The reason it concerned me is because one night I pulled into a drive thru and while I was at a dead stop for a good while, the engine started trying to die. Looked down at the OP needle and it was totally bottomed out. Not sure if it was related or coincidince.
 
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