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Discussion Starter · #1 ·
Here's some background on what's wrong with my car:

When I first start the car and the engine is cold, it idles fine. However, when I step on the gas and give it power it sputters and sometimes dies. When the engine warms up, the problem dissipates to almost nothing (but is still there).

I've had the carburetor rebuilt and have installed the correct choke tubes.

A shop told me that I am only getting 4 degrees of vacuum advance from my distributor, or something. Clueless on engines :p

Now... the plan is to drop the car off at a repair shop and get an engine diagnosis for $60. Seems like a good deal to me.

I am assuming that the end result will be replacing the distributor. It may be jumping the gun a bit but I want to figure out which one to get in the case I need to replace it.

My engine is all stock as far as I can tell and I am just looking for a good distributor for the best price. I've heard that it will be roughly the same cost for a performance dist. as getting mine rebuilt or buying a rebuilt one.

So... what do people suggest as a good distributor? My '68 has a 289 2bbl and this car is just a weekend cruiser.

Also, what kind of prices are we talking for the dist? The shop says that install will only be $90, so I think that's not too bad.
 

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I'd try to replace the vacuum advance can on the distributor, it's $20 and you can do it with hand tools without removing the distributor.
 

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A lack of vacuum advance should have no effect on driveability. In fact at wide open throttle the vacuum advance is zero.

However, a failed diaphragm in the vacuum can will cause a vacuum leak, which will cause rough running. Try disconnecting the vacuum hose from the distributor and plug it with a bolt or screw and see if your problem goes away.

Aftermarket distributors start at about $200, and look out for the ones that require a capacitive discharge igniton box (like an MSD), because that adds another $180 or more. So a remanufactured points distributor is far and away the cheapest option.

I won't comment on the $90 quote to install a distributor. It's a simple job, particularly on a Ford where the thing is right up front. But there's also overhead, and the possibility of screwing up the job. So $90 isn't a deal killer, if that's the best deal you can find.

I was pricing the idea of rebuilt Duraspark stuff but the total seemed to be closing in on $200, so I went for the bling of a Summit brand (I think they're made by Mallory) Ready to Run for $230:

http://static.summitracing.com/global/images/prod/large/sum-850303_w.jpg
 

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$90 labor to install a distributor is a rip off. It is something you can do yourself in 20 minutes with nothing more than a screwdriver to pop off the cap and swap it over to your new dizzy, plus a half inch open end wrench to loosen and tighten the distributor hold down clamp. Just have to borrow a timing light to re-set the advance.

I concur with the other post here, that if you are only pulling 4 degrees of advance off the vacuum advance, the cannister on the side of the dizzy is bad. Swap that first, before doing the engine diagnosis and save yourself $60.

If fact, if you want to bring the car over to my shop here in Suisun City, I'll show you how to check the timing and how much is being pulled in by the vacuum advance. We can check it out, and if that is your problem, I have a spare dizzy out of a 66 A code with a new vacuum advance unit on it that I'll swap in for you. If that cures your problem, pay me $20. If that does not solve your problem, we can search around to figure out what else might be necessary. I assume that South Bay means the San Francisco area and not the San Diego area, correct?

Sounds to me like you have two things going on, a carb adjustment that wasn't set up right, plus the timing issue on the dizzy.

Send me a private post with your phone number if you are interested and I'll give you a call.
 

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Discussion Starter · #5 ·
70sportsroof said:
If fact, if you want to bring the car over to my shop here in Suisun City, I'll show you how to check the timing and how much is being pulled in by the vacuum advance. We can check it out, and if that is your problem, I have a spare dizzy out of a 66 A code with a new vacuum advance unit on it that I'll swap in for you. If that cures your problem, pay me $20. If that does not solve your problem, we can search around to figure out what else might be necessary. I assume that South Bay means the San Francisco area and not the San Diego area, correct?

Sounds to me like you have two things going on, a carb adjustment that wasn't set up right, plus the timing issue on the dizzy.
I should be more specific in my post... it's South Bay in socal, not up north. Thanks for the offer though... I really wish I could find a dependable shop down here. Every time I get a quote and post it online people freak out about how high it is.

Also, I'm sure you're right about the carb still not being set correctly. It was installed with this vacuum advance problem, so if and when it gets fixed I'm assuming that there will need to be an adjustment made.

I'll look into trying to do this myself, but I'm really tentative around engines. Is it really that easy to do this?
 

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Way way way easy to do this. With the cap off the dist and the dist in the engine block, you will see that a rod extends from the vacuum advance cannister into the dist. body and attaches to the plate upon which the points are mounted. The vacuum pulls the plate, which changes the timing of the points opening and closing. Changing the cannistor involves disconnecting the rod from the plate, unscrewing the mounting screws for the cannister, then reversing this with the new cannister.

After you do this, you can borrow a timing light from autozone (get the kind with an adjustment dial) and check the timing. Take some white fingernail polish or typewriter white out and pint a thin line across the balance at zero degrees TDC. Put a white dot on the end of the timing pointer. Hook up the timing light per directions and start the car with the vacuum advance hose to the dizzy plugged. Point the light at the timing pointer and pull the trigger. You will see the line on the balance glowing for you. Turn the dial on the timing light until this line and the dot on the timing pointer are lined up. Look at the dial and see where it is pointing. That is the number of degrees of advance. It should be between 8 and 12 degrees advance. I think with the auto trans the base timing is to be 12 degrees.

Now, connect the vaccum advance hose again, have someone step on the gas and run the rpms up to around 3,000 to 3,400 rpm. Hold the trigger down ont he timing light. As the rpms build you will see the timing line change and get farther away from the dot onthe pointer. Once the line stops moving, have the helper hold the engine rpm stead and you adjust the dial on the timing light to bring the balance line and timing pointer dot into alignment again. Once that is done, shut off the engine and look at the dial. You should have between 32 and 36 degrees and the rpm's at which the the timing line stopped moving should have been around 3,200 rpm. This is called having all your timing dialed in by 3,200 rpm. Total timing, which is your base timing set by your initial dizzy adjustment, plus the centrifugal advance from weights inthe dizzy body, plus the vaccum advance should be around 34 degrees.

To increase the base timing, loosen the dist. hold down clamp and rotate the dist. counterclockwise, then tighten the clamp. To cause the timing to "come in" earlier (at lower rpms), you can use lighter springs on the weights inside the dizzy. to compute the vacuum advance, compare total timing, with total timing with the vacuum advance hose disconnected and plugged. The difference is your vacuum advance. To bring the vacuum advance in earlier or later, shims are used between the cannister and the dist. body, whic has the effect of changing the length of the rod connecting to the points mounting plate.

I suspect your carb is adjusted lean, since it runs fine cold, but once warm(when the auto choke no longer takes affect), it stumbles. The air fuel adjustment screw can be adjusted by turning it in until it is lightly seated, then back it out 1.5 turns. That should be ballpark.

John's Mustang parts in San Diego, just south of downtown and more or less north of chula vista, has a shop in back. The owner knows what he is doing, but there is a young punk know it all there that doesn't really know what he's doing. If you can get John or someone older to work on your car, it should be reputable. Not cheap, but reputable.

Try the fix yourself and you will probably get it done right. If you get jammed up while working on it, you can give me call and we'll walk through it together.

I used to live in SD in my college and law school years. I went to church in the South Bay area (Imperial Beach). Lived in Point Loma, then Mira Mesa, then Linda Vista. Nice town back in the day. Now, like everywhere in SoCal, it's built up.
 

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Before you get too excited about doing this (messing with your distributor) I'd suggest springing for a timing light. You can buy a servicable one at Walmart for less than $50. You have to have a timing light to check and reset your initial advance.

Also...just be aware that this job goes from an easy deal to a toughie if:

1. Your distributor is stuck in the block.
2. Your oil pump shaft comes out with the distributor (actually very likely..mine has every time).
3. You drop the oil pump shaft back into the block (done that twice too)
4. You end up having to pull the oil pan off to get the oil pump shaft out of there.
5. Your crossmember bolt breaks off in the frame when you try to pull the engine crossmember to get the oil pan off.
6. You knock the frame nut back into the frame while trying to get the broken crossmember bolt out of it.
7. You blow the power valve out of your carburetor do to a wrong initial timing setting.
8. You don't mark you rotor position when you pull the distributor or can't figure out how to get it back in the same position when you reinstall it.
9. You (or someone else) rotates the engine with the distributor removed causing you to lose TDC.


That's just nine things that I've seen happen. I'm sure other things could go on too. AND to top it off...your problem very well might not have anything to do with the distributor.

The joys of owning an old mustang never end.

I'd suggest you put an APB out on a VMFer in your neighborhood that can take a gander at it for you and maybe help you a bit.

Phil
 

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180 Out said:
A lack of vacuum advance should have no effect on driveability. In fact at wide open throttle the vacuum advance is zero.

However, a failed diaphragm in the vacuum can will cause a vacuum leak, which will cause rough running. Try disconnecting the vacuum hose from the distributor and plug it with a bolt or screw and see if your problem goes away.
I agree 100%. I don't even have a vacuum advance on either my '66 or my '69.

Don't let them replace the distributor. The only reason you'd need a new one if there was something wrong with the MECHANICAL advance. You can swap out a vacuum advance pod for about $25 and 5 minutes of work, if it's leaking.
 

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First you might want to pick up a book on small block Ford engines. They detail tune ups. Sounds like you need a tune up, including points and condensor, perhaps a new vacuum advance, and maybe a distributor cap, rotor and plugs. A decent book will show you the way. I agree with Carpal, a timing light is essential. And you can see what is happening -- you never know what a shop is doing unless you find a hotrod shop you can trust. A good way to set the carb. is with a vacuum gauge and tachomoter, but setting to highest vacuum is a very good place to start; the book will show you how to do that. And if you don't want to mess with points, then the Pertronix I is a great addition that eliminates points and condensor, though it is highly advisable to learn how to work with them and keep a new set in your travelling tool box just in case the Pertronix unit fails. Also, is the top of your coil clean? If it is greasy, the engine will act as you've described.

Is there a Mustang club in your area? You can learn lots from such people.
 

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I bought a procomp billet distributor re-curved to my eng combo for 149.00, the thing is great and the internals lokk exactly like a duraspark.
 

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I bought a re-built distributor from Autozone, I
think it was about $49.00, lifetime warranty. Looked just like the old one I took off, came with
vacuum advance. That was 2 years ago, no problems
at all!
 
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