200ci 1965 Mustang- Need some experienced help

akimball442

New member
This is going to be my first post here, and may be quite long. I hope anyone with a great deal of experience with this engine could find the time to read it, and assist me with the problem I'm having. I'm going to be as detailed as possible, in order to avoid wasting anyone's time.

Quick backstory: I'm a diesel mechanic, and I work on mostly mid-range engines on buses. That's my 40 hour day job. In the evenings, I work at a small automotive shop, where we do repair work for locals. We will work on just about anything, but as you might expect, most of the vehicles are modern computerized vehicles. We've done some pretty intense jobs, both of us pretty experienced and not afraid of much, and we've had great success.

When it comes to old cars, my personal experience lies with GMs and anything German. I'm an avid Mercedes fan, and I own and old Cadillac as well. So my Ford experience is mostly limited to modern Fords, nothing like this Mustang.

This 1965 Mustang belongs to a regular customer, and she is about the nicest lady you could ever wish to meet. She's one of those great people who you can find yourself talking to for an hour. She purchased this car, an amateur restoration from the look of it, a couple years ago. She loves this car more than anything in the world, and since it was taken out of storage in the spring, it's been nothing but trouble. Last year, it ran perfectly well.

The car started fine where it was stored, and she drove it about a mile before it quit, headed up a slight grade. She had it towed to our shop. The weather was cool, and it wouldn't do much more than stumble and cough a little- the choke was stuck open. I pushed the choke closed, it started fine, and drove into the shop. She also noted it had leaked (something).

Every time we started it, it ran fine. The leak was a freeze plug- it had apparently rusted, as it didn't look like it had blown out in a normal way. Replacement required removal and re-installation of the exhaust manifold. We gave it its beginning of season service- new filters, fresh oil, and took it on a few long-ish test drives with no issues. It ran fine. Also worth noting- we live in hilly terrain, with some pretty steep grades. That becomes important.

Having added about 30 miles to the odometer, we returned the car to its owner, and it wasn't a day before she called and said it had quit on her, and she had been able to restart it and limp it home, running poorly and often quitting. We went and picked it up at her house- it ran fine. Of course. I drove it around a bit, no problems, ran fine.

One nice Saturday, I decided to let it sit outside and run, and it ran for probably 4 hours, perfectly well, nice and cool, until it started running poorly. By the time I noticed and walked over to it, it had stalled. I was unable to restart it, but it would start on ether. Perfect, so it has a fuel delivery problem. The next day, it started, and I drove it in the shop. After installing a tee into the fuel line and connecting a gauge, it was discovered that the fuel pressure was only around 3PSI. The specification is 4.5PSI. No obstructions in the lines, fairly new filters, clean fuel- we replaced the fuel pump. Fuel pressure was just shy of 5PSI with the new pump, drove the car, it ran fine, back to the owner.

A week went by, it quit again, this time she was stranded with the car about 6 miles away. I went down to meet her, and was able to restart it. I was going to have her follow me with my car, but I was unable to go more than about 100 feet at a time, and there was a very long hill between us and the shop. We towed it back. It started up and ran ok once we got it there, but I wasn't able to make it more than about 1/4 mile before it stalled. Well, at least now I'm duplicating this problem. Dragged it back to the shop again.

It has not ran properly since.

Without typing another 30 pages, the following items have been replaced. Total shotgun troubleshooting, as this engine passes EVERY TEST.

Points/Condenser
Plugs/Wires
Ignition coil
Fuel tank and all its components
Fuel lines
Carburetor
Fuel pump - disconnected original pump and have put an electric pump in place.

The car starts and runs perfectly. It has great acceleration, absolutely no trace of hesitation. On flat roads, it's no problem to get it up to 55-60 mph. As soon as you start going up the slightest grade, it will quit like someone pulled the plug, and that's it. It's like the float bowl runs out of fuel and you're done. Then it's usually difficult to restart. Keep in mind the symptoms have never changed, with any of the above components having been changed- even the carburetor. Back at the shop, either limped back, or towed.. we can do some tests, as the problem is getting worse and worse.

Ignition is never the problem, and the timing is correct. When it quits, even if its allowed to stumble and die in front of us at idle, the spark is ticking along to the end. Cranking immediately shows good spark.

I installed a clear fuel line between the filter and the carb to make sure fuel was making it to the carb and not vaporizing. It's fine- a solid line full of clean fuel. Looking into the carb and increasing the RPMs, you can SEE the fuel moving through the carb.

So we have spark, we have fuel. But it's leaning out and dying. When it starts to stumble, choking it a little bit, or misting some ether over the carburetor will cause it to start running nicely again.

Another interesting point is that it seems to be burning through exhaust manifold gaskets, but I'm not sure if that's a cause, symptom, or unrelated problem.

So what I am 100% sure of, is for some reason this thing is going lean... to the point it won't run... but I cannot for the life of me figure out why. It's very frustrating that this seemingly simple engine is beating us up so badly. It can run for a good long while before it starts acting up- unless you put a hill in front of it, and then it starts misbehaving.

I'll be grateful for any suggestions... hoping some of you guys with years of experience on this engine can give me a different perspective- because for the first time in my career, I'm completely out of ideas.

Thanks,

Aaron
 
Aaron, the fuel tank cap vent is clogged. That would cause the engine starving for fuel after driving??? Hook a fuel pressure gauge to the fuel pump outlet when driving & see what happens.
Check the float in the carb & there should be a wire clip to pull the needle from the seat when the fuel level is low. If that clip is missing the needle will get stuck in the seat. Also check the float drop setting in the carb. Good luck, Bill
 
Thanks for the reply.

I have driven it without the fuel cap in place. It's actually got a poor gasket and doesn't seal well anyway. No change in performance.

I have driven with the fuel gauge taped to the windshield, and it does not lose fuel pressure at any point while driving. Worth noting is that the electric pump currently in use is supplying a bit more pressure than is called for, between 5 1/2 and 6 PSI. Should be excessive, really.

Also, I've read the hose between the tank outlet and the steel fuel line can collapse, it too, has been replaced with a thick walled hose, and does not collapse.

Aaron
 
For some reason I missed your comment on the carburetor. It has a new (well rebuilt) one in place. Do you suppose that both could have the same problem, even though the original ran fine last year?

It really DOES act like a low float condition, but looking into the carburetor, you can see lots of fuel flowing in as you open the throttle, along with good fuel PSI and volume to the carb.

I've never monkeyed with one of these Autolite carbs before, but it doesn't *seem* like it could be too complicated.
 
Aaron, so when it quits running, & you actuate the throttle does the accelerator pump shoot fuel into the venturi area?? If it shoots fuel & the fuel bowl is full I would replace the condenser & road test. Do you have voltage @ the coil??? Another way to check the coil is by heating it with a hair dryer & see what happens.
 
I replaced the condenser last week, and the points since I was in there. Dwell is set to 35deg.

I replaced the ignition coil early in the season, and then as another test, I used the one from 1964 Cadillac which is very reliable. Voltage at the ignition coil is about 9.5V with the engine running at idle, which makes sense with a resistor wire in place. The coil is of the type which requires a resistor to be used.

Yes, fuel shoots into the carburetor, the accelerator pump appears to be working well.

Often, after the initial 'quit,' if you allow the car to coast for a bit, then 'feather' the accelerator pedal, it will come back to life.

Last night, it died and I was able to get it running by staying on the accelerator, but as soon as I let go of the accelerator, it would quit. There was no way to put it into gear and get it turned around or back on the road... I actually had to back down a hill and into someone's driveway.

Once back to the shop, it was very hard to get it to run at all, although it'd run on ether. Using an inline spark tester showed spark present during all testing.

I suppose it's possible that the inline type spark tester wouldn't necessarily show a weak spark, however, the fact that spraying ether across the carb causes it to run or run better suggests the ignition system isn't causing the fault.

It's very strange.

Aaron
 
Do a volume test on the fuel pump. You are right you have a real challenge here.
Pull the fuel sender & see if the sock is collapsed on the fuel pickup line??
 
Thanks again for the replies.

I have not actually measured volume, as I didn't expect it to be a problem, but it has crossed my mind. Do you know what the specification is offhand? If not, I'll try to find it.

Thanks,

Aaron
 
I had a problem very similar to this with my 65 Ranchero. I did the same thing as yoy, i checked everything, replaced almosg everhthing, then found out it was the filter IN the gas tank at the pickup. Its a sock style filter. I think you have to replace the whole sending unit as the sock filter doesnt come off.

Drop the tank and check it out.

Good luck,
Ryan
 
Hi, the tank and all of it’s components were replaced.

The tank screen on the original pickup probably flowed better, since it was torn in half. :shock:
 
akimball442":27srij4y said:
Thanks again for the replies.

I have not actually measured volume, as I didn't expect it to be a problem, but it has crossed my mind. Do you know what the specification is offhand? If not, I'll try to find it.

Thanks,

Aaron

On doing a fuel volume test, disconnect the coil wire and fuel line at the carb using a suitable container crank the engine over with the starter then measure the amount of fuel volume. Your stock type fuel pump should be putting out a pint of fuel in 30 seconds or less if not you need to replace it. A Autolite carb should work good with 3.0 to 4.5 PSI, check the float level (wet fuel level) is set correctly. Check the fuel filter, Is there a chance of any trash in the fuel tank that is being picked up and clogging the fuel line to fuel pump? Good luck :nod:
 
Thanks for the response.

The mechanical pump doesn't work. I probably should make Napa replace it under warranty, as it DID work, but only for a very short time.

Since then, the fuel tank, pickup, etc, has been replaced with new. The fuel that comes from the tank is fresh, in fact, a clear filter has been installed and continues to remain clean. To be truthful, the same can be said for the original tank- it was impressively clean.

As mentioned, the car currently has an electric pump. I should assume that I can run a similar test with the electric pump, to see if it can move a pint of fuel in the 30 seconds.

I suppose though, that if a mechanical pump were to move that amount of fuel, it's expected that it would move a larger volume of fuel as the engine speed is increased. In other words, if the electric pump is producing nearly what the mechanical pump would produce at cranking speeds, it's probably insufficient, since the output wouldn't increase with engine speed, just battery voltage.
 
akimball442":1oe00h2i said:
Thanks for the response.

The mechanical pump doesn't work. I probably should make Napa replace it under warranty, as it DID work, but only for a very short time.

Since then, the fuel tank, pickup, etc, has been replaced with new. The fuel that comes from the tank is fresh, in fact, a clear filter has been installed and continues to remain clean. To be truthful, the same can be said for the original tank- it was impressively clean.

As mentioned, the car currently has an electric pump. I should assume that I can run a similar test with the electric pump, to see if it can move a pint of fuel in the 30 seconds.

I suppose though, that if a mechanical pump were to move that amount of fuel, it's expected that it would move a larger volume of fuel as the engine speed is increased. In other words, if the electric pump is producing nearly what the mechanical pump would produce at cranking speeds, it's probably insufficient, since the output wouldn't increase with engine speed, just battery voltage.

Ok with most electric fuel pumps volume is good but its more about the pressure build up. So dose the pump slow down and then stop pumping after a short time? It sounds like the fuel system is good up to the carb. With the Fuel pump running and Looking down the carb (with the air cleaner top off), engine is warmed up is the choke fully open or if engine isn't warm hold choke open do you notice fuel dribbling down the carb throat?

Here are the basic tune up specs and some extra info on the stock LOD Distribitor for trouble shooting.
Stock 1965 Ford Mustang 200 tune up specs

Plugs are gaped to .034, Points are set to 38 degrees Dwell (best way) or in a pinch gap them to .025,
Base timing is 12 degrees BTDC with a Auto trans, Fuel pressure is 4.5 PSI, Idle RPM (Auto trans) is 485 in drive (AC if you have it is off).

In addition often people need to learn a little bit about how the early Ford six'es LOD distributor and carb's (SCV) are matched to work together, they don't work like most other vacuum advance systems. There is a good article that will help you in getting to know how this system should work (see below link) it may help you to figure out if its causing any problems. When everything is right and in good condition a 200 will idle smooth down to as low as 425 to 450 RPM in drive. Also check that the carb's choke system is working correctly, some pictures will help to see if you have all the correct parts installed. Good luck :nod:

The Ford Load O Matic system
http://www.classicinlines.com/Loadomatic.asp
 
bubba22349":2c14ydde said:
On doing a fuel volume test, disconnect the coil wire and fuel line at the carb using a suitable container crank the engine over with the starter then measure the amount of fuel volume. [highlight=yellow]Your stock type fuel pump should be putting out a pint of fuel in 30 seconds or less if not you need to replace it.[/highlight] A Autolite carb should work good with 3.0 to 4.5 PSI, check the float level (wet fuel level) is set correctly. Check the fuel filter, Is there a chance of any trash in the fuel tank that is being picked up and clogging the fuel line to fuel pump? Good luck :nod:

Well, here's the winner, I HOPE.

Since I have an electric pump, I decided to go ahead and check the volume of fuel delivered over 30 seconds. My reasoning is that it should meet or exceed the flow rating of the mechanical pump, especially since the specification of one pint in 30 seconds is measured while cranking the engine. During cranking, it's reasonable to expect that the delivered volume would be the bare minimum, as the pump isn't pumping very hard until the engine is actually running.

Well, the results of the little electric pump are uninspiring. No pint of fuel in 30 seconds, no half a pint... maybe 6 or 7 ounces.. in 30 seconds.

So the lesson is, of course, that good fuel pressure does not equal good fuel volume.

I have ordered a better pump, one rated for 32 GPH at the specified 4.5 PSI.

If the volume increases, and the problem resolves, I will then look into getting a functioning mechanical pump.

I'll report back with my results tomorrow evening.

Thank you again, to all who have replied and made suggestions.

Aaron
 
"... good fuel pressure does not equal good fuel volume..."
I'll B wrkin on that 1 for awhile. ¯\_(ツ)_/¯
Isn't science fun ?!?
Thanks 2 ALL 4 the experiment'n initial info.
 
Well, it runs. Actually, for 200 cubes it's kind of impressive.

I can't thank all of you guys who've made suggestions and let me re-hash this thing the last few days.

Fuel VOLUME was the big deficiency, and having been provided some specifications was a major advantage. With the new pump, everything seems to be as it should.

Thanks a million times.

Aaron
 
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