66 Mustang 200 6 Cyl. Problems

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I just found this site the other day while searching the internet and I believe its just what I was looking for.

Let me start off by stating my wife’s car is a 66 Mustang Coupe with a 200 I-6 and auto tranny. The car has around 96000 miles, was cleaned and shined up about 5 years ago. During this time, the motor was supposed to have new seals and gaskets installed. (Her uncle did all the work to this car) Currently, the car will start and drive anywhere you want to go. However, there are noticeable problems with this engine that need my attention. The carburetor on this car is new, and has actually been replaced twice due to the fact apparently the car wasn’t running correctly.

Listed below are the symptoms:

Upon starting, the car seems to take a few moments before it idles out correctly, which I believe could be just an issue of letting the motor warm up. It will idle but after a few minutes it seems the motor begins to miss somewhat. No mater how long you run the motor, upon takeoff from stop if you gas it the motor completely dies. So in order to get this thing moving you must be “easyâ€￾ on the pedal to take off. Around 50-60 mph if you try to cruise the car begins to miss more. Anything above or below those speeds the problem seems to disappear. When the car is run WOT, it doesn’t seem to have much of a problem moving on down the road, but it not as strong as I know it should be. My belief is that it has something to do with the timing, but I would like more input from the people with the knowledge.

I understand more information may be needed, so ask me questions and I will answer to the best of my knowledge. Thanks.
 
The carb was replaced...what carb and distributor do you have? Some setups are meant to be matched. It could also be your carb jetting.
 
Welcome

Timing is a good thought. That vintage would have come with what was called a Load O mattic distributor. It was a funky vacuum only advance (instead of vacuum and mechanical centrifugal weights) setup that used a special section (vacuum port and spark control valve) on the carb. If the carb has been changed its possible the the current carb does not have this SCV port and or valve. Later 68? and most other engines used the more common mech/vac setups that do not require a special carb.

You can read the sticky topics at the top of this section to learn more about the Load O matic and the SCV.

If the carb is good (whole other topic and trouble shooting) a newer dizzy would be the way to go. At the same time going to something electronic like a Duraspark would also be something to consider.

These issues come up fairly often here. Keep reading in this section, there is lots of info. You can start with some basic searches then narrow them down as you learn more then you will be able to ask some specific questions and 'get er done' or I guess ' get it done for her' in your case.
 
I will vote for timing problems.

Either because static timing is set incorrectly, or because that peice of crap load-o-matic isn't working right (which is nearly always the case).

If you intend on driving this car at all, and want to have it for a while, you should do the relatively inexpensive upgrade to the Duraspark II ignition from a later model 200. It will seem like a new car once you do.

Welcome to the forum!
 
HowdyBack 97 & All:

I was waiting for more details on carb and distributor, but got impatient. Patience is not my best subject! So, I add the following by assuming (I know!) that this is a stock '66 with an 1100 Autolite carb with a SCV and a Load-O-Matic distributor.

I'm thinking that you may have several problems- both carb and ignition. I'd start by verifying correct point gap, the initial spark advance setting and verify that there are no vacuum leaks between the carb and the distributor vacuum canister. I'd also verify that there are no leaks inside the vacuum canister. If all is well there it is carb time. If not, fix what needs fixing and reassess.

Moving to the carb- I'd visually verify that the accelerator pump is functioning (poor take-off) and that the SCV is working as designed. I'd also be suspious of a low float setting (effecting steady cruise).

AKT- just because you replaced the carb does not mean that the replacement carb is set up correctly. Was the carb really new? or a rebuilt? I would not trust either.

Also, I would not change out any parts until you have thoroughly assessed what you have. Identify and/or solve these problems before adding another variable.

I will be looking forward to more info and feedback. I will be away from my computer Monday and most of next week, but I'll be thinking about this.

And Welcome to The Forum.

Adiosl, David
 
I didn't have alot of time this weekend to take pics like I wanted, but I found out the carb is actually rebuilt. After looking the carb over, I would have to believe its part of it not most of the problem. It looks like gas is leaking out somewhere and for someone to see it for the first time would have to believe it would be the original (its very nasty). I have alot of investigating to do because my wife only knows what her uncle told her, and so far I am having to verify everything she tells me by checking for myself.

As far as the distributor, where can I see a link to the one you are recommending?

If time allows after work, I'll slide out to the garage and take pics of the engine bay and let you guys post away.
 
Here is an 1100 which would have been the factory carb on a 66. Its just sitting there for this picture so there are a bunch of hoses and such already removed. The plastic arm thing to the right of the scv stuff only came on automatic transmission cars and does not seem to be critical because I have read about many people running manuals with this one or running AT's without it and not having any issues.

scv.jpg


A common place for leaks on these seems to be when that little brass nut looking thing is missing between the carb and the filter. Its actually an adapter. The filter has a tapered thread on it (uses a sealer like tape) and the carb is a standard thread (uses a little washer gasket thing).

If there is fuel leaking from the main part of the carb there is most likely some sort of float or needle and seat problem. In theory there should never be enough fuel in the carb to leak out.
 
I wished my wife's carb was that clean. Here is the location i found the problem.

mustangcarb.jpg
 
So, first off - that's an autolite 1100 w/ SCV as you have identified. It has the Dashpot for an auto transmission.

If gas is leaking where you indicate, then your float is set too high or your fuel pressure is too high.
 
Well if you were thinking about working on a carb the 1100's are pretty simple. Rebuild kit cost around $25 Napa Echlin #2-5579 (thats what is on the box, I think there is more numbers or letters). The kit comes with an exploded diagram and a crappy little ruler thing for setting float level.

Your problem could be:
worn needle or seat (part of kit)
crud in needle or seat
non floating float (not part of kit)
improperly set float level

Like others have mentioned it could also be a fuel pressure issue that would be worse with any of the above problems. The quality of pumps are not what they used to be. I think they have a 'one pressure fits all' concept the last several years.

I seem to recall that I had to grind a bit off the bottom of the needle to get to the right float level and geometry. If I used it the way it came in the kit with my float it would hit something before it seated. The brass floats you can shake to see if they are full of fuel. Most of the plastic ones are solid and its hard to tell if they are still correct. Many of the earlier plastic ones do not do well with alcohols that are found in a vast majority of our fuels now days.
 
I'd also take a look at your points. I'm assuming you haven't touched them in 5 years (and assuming you are still using points). If so, they may need to be replaced, readjusted, or upgraded to a non-points ignition. That should smooth out some of the smoothness problems of idle. For the sluggish response on throttle, I agree your carb may be in need of a rebuild or at least, a reset of the fuel float and checking the dashpot operation. Quick check is when the car is not running, take the air cleaner off and look down the throat of the carb (with the choke forced open). operate the throttle linkage and you should see a squirt. If not, you know the problem. However, it could also be putting out too much.

It is the one problem I had with the 1100, that dead spot when you punched the gas.
 
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