From the top: ‘73 Q code convertible

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Joined
Jun 14, 2019
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Location
Coachella Valley (Palm Springs)
My Car
1973 Convertible, 351 4v CJ, C6, Mach 1 Decor options, power: steering, brakes and windows, a/c, Rally Pac gauges, Deluxe interior.
[url=https://ibb.co/ZVjjKXW][img]https://i.ibb.co/zrMMbxG/s-l1600-2.jpg[/img][/url]
And in the beginning... (btw, a forum dedicated to our own builds/restos is such a great idea - thanks)

Introductions have been made in the New Users forum, so this is my rebuild/resto thread.  My goal is an original-as-possible sweet “weekend cruiser” with only the few modernizations that are more or less essential to dependable driving (i.e., I never ever want to have to adjust points again — my absolute nemesis!). I plan to work my way through (in this order) 1) dependable, 2) comfortable, 3) attractive up to awesome ride.

The car arrived yesterday so I got my first thorough unattended inspection.  No complaints about the seller; it was a quick & efficient transaction and the description was thorough and accurate, however... it’s always the ‘what they don’t say’ you have to look for.

My first impression?  “Welcome home, beautiful!” (Seller’s photos)





And now reality.

Exterior:  “par” for 46 year old car not maintained beyond the essentials.  2nd paint job was crap.  Several small trim pieces (hood locks, side panel “Mustang” script) missing.  Def needs a new top (knew that) but the top mechanicals are *excellent*.  Endless body tweaks and adjustments needed. Floor pans and trunk, solid other than (known) dime size hole in passenger rear trunk well.  More troublesome: that “little scrunch” on the driver rear corner will probably necessitate a quarter panel replacement.

Being the first year for the 5 mph bumper mandates, I expected they’d seen punishment.  That said, front bumper looks pretty good although it seems a bit set back:  the urethane attached to the bumper for the sides that covers the gap to the fender overlaps onto the fender by about 1/2” — can the bumper just be adjusted back out?

Under the hood: Seller replaced air, oil and fuel filters, all the fluids, battery, coil, voltage regulator and upper/lower radiator hoses.  It’s good because I would have done that anyway, but not good because the old fluids are a good diagnostic. P/s pump leaks (a lot) — no fluid even showing on the dipstick — but when the engine is running, works fine(?).  But I can’t really take it our for spin until... the leaky radiator is fixed (has been ordered and yes, I’m staying with copper/brass and upgrading to 3-row).

But... lots of “ponderables”.  Why is the oil dipstick coming up under the a/c compressor rear hoses?  Not near, “in”.  What were they thinking with that hose that’s about a foot too long (can’t yet say what the hose is for, but it hangs down 3”-4” under the engine).  And “Hey, you:  ya left one of your sockets attached” (I remember the excruciating effort to get up in there with my ‘71 many moons ago and then when extracting my wrench, the socket stayed behind.  But I never left one.)

With engine running:  starts *nearly* flawlessly *nearly* every time!  And then the fun begins... A few misfires until it gets warmed up but then purrs smoothly.  However, exhaust smells way too rich and idle never drops below 1k.  After getting to normal temp a few revs (hold at 2500) reveals:  stumbles on the way up, say at 1500-2000 rpm as if it were getting too much fuel, but then surges beyond that.  If you’re holding 2-2500 rpm and just take your foot completely off the accelerator: spin down to full stop and off (dead).  A slow release of the pedal and it just returns to idle.  I will be inspecting every vacuum tube under the hood I can find today.

Underneath:  cursory inspection.  Old undercoating needs to be removed/replaced, but it’s really done it’s job.  No rust other than expected surface dust.  Rear end does not leak. No oil/fluids coming out of unusual places.

Interior: Ulpholstery and carpet def ready to be replaced.  But workable as is for now. Dash cracked (meh, not dreadful.  Add to the list).  Passenger and driver seats were switched so that will eventually go back (as is, the seat back release levers are on the side furthest from the door), console is in good shape except the console liner/bin has part of the bottom cut out for who know’s what) and inside, first owner-added “what does this switch do?” . Instrument lenses clear!  Uh, who knows how to get that mess of a horn working — without replacing the wheel? (see photo).  All major switches work as do the power windows (passenger’s needs new cam, but you can hear the motor purring as it tries.  Bueno). Wipers work and park perfectly, but alas, no washer.

HVAC:  well... compressor known as not working, but, controls mostly ok.  Fan speed good.  Air to a/c vents and floor vents fine, except hi “Hi/Lo” (no mixing; all upper or all lower).  On “Heat” it should send most air to the floor, next position over, mix floor and defrost, on Defrost, full output to windshield.  Seems we are at “Mix and Full Defrost” only.  Maybe some jammed doors, or missing/broken vacuum hoses.

Radio:  “silent”.  Either not getting power, or dead; TBD.  Console clock:  same.

Nighttime inspection:  all exterior lights good except for one side marker lamp.  High/low work (but oh my do those headlight need to be aimed).  Interior courtesy lights all working (not many in a ‘vert), but... no dash or console lighting.

Which led to this morning, crawling under the dash, to see what I might see, regarding the dash and console lighting and radio power.  What.  A.  Hornet’s.  Nest.

So many splices! And a new “what does this do?” switch.  Fuses in the fuse block a-ok, so about the radio, there must be an in-line fuse somewhere... or something is just completely unattached.

There you have it.  I have about a grand worth of parts on order — so while I wait, I’ll be here reading up on “disassembling the instrument panel and center console”.

And yes, since this is a (hopefully) ongoing thread of my project and progress, any of your $.02 you want to throw in along the way would be welcomed.

 
Sounds like you did okay for the closing price. Rust can be a huge expense on a convertible and with such a nicely optioned car, you're ahead of the game.  I'll tackle stuff in order on your post.

Quarter- a good body shop can pull that quarter and make it right, probably no need to cut into the car. 

Front bumper - yes, they can be adjusted and I've seen more than one with a pile of shims between the bumper and the absorber. 

P/S - seal kit for the pump is about $10 and quite easy to install, once you get the pump out. Get some Type F ATF in there before it hurts the pump. At this age, the whole system will probably need to be rebuilt/resealed. Hoses are cheap and readily available, the box comes out pretty easy and there are places that do the rebuilds.

Dipstick - that the heater hoses it's threading through, use a longer hose when you replace them to push them out away from the dipstick. The big black rectangular hose is the outside air duct. It pulls cool air from below the engine compartment. Looks like it was replaced at one time and never trimmed to length. 

Engine - guessing you have the original Autolite 4300D. It's known to be a bit "cantankerous". 

Interior - carpet - be sure to get the Mass Backed option, it fits much better. Looks like there's something going on with the passenger seat, might have a broken weld internally. 

Horn - horn pad and all the parts are available reproduction. The whole pad comes off with two phillips heads from the rear and has a couple wires with pusch-on terminals on the wheel. 

https://www.npdlink.com/1965-1973-mustang/steering/steering-wheel/1970-1973-original-2-spoke

HVAC - selector has a vacuum switch known to fall apart. A fairly easy fix once you get there. 

Radio - fused only at the fuse block. Might be disconnected behind the dash. Clocks are known to burn out. 

To get you started - 1973 wiring diagrams are attached below.

1973_full.pdf

 

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  • 1973_full.pdf
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Thanks! Yes, given what I've seen since, I think I got a fair enough price for far from perfect but a nearly perfect features/options in overall decent condition.

The "a good body shop can..." part is a huge relief. It was going to be a "have to be later thing" anyway as I'd want to do that the same time as a repaint. The underlying yellow (6E) isn't bad, but the black stripes, especially on the hood are a mess. All that's for after I get it running & driving dependably. I did get Type F fluid for the steering pump nearly immediately. I'm fairly certain I'll be taking your tip for restoration.

Sort of like the horn: ya look at it and think "what a mess" but then after you step back and someone sprinkles some sanity around, it's not so bad.

Given the (old) a/c is not working, and eventually I'll upgrade to R134a and that changes out the hoses, is there any reason not to pull the compressor now and just leave it out? Having more room to work under the hood even if temporary would be nice.

And my hope, once I get behind the dash, is to find the radio was just disconnected for whatever reason. The most intriguing thing will be chasing down what the two owner-added switches are four since I can't find any extra equipment (fog lights, for example). There's one cheesy switch inside the center console and another decent switch mounted just to the left of the radio, toward the back.

Again, thanks for the tips!

 
You can remove the pump, it has it's own belt, so removing it and the upper sheetmetal bracket won't hurt anything. If you want to remove the big cast iron lower mount, you need to put a spacer behind the power steering pump bracket.



 
Nice car. 73 Q code convertibles are fun to drive and to repair. Make sure you have the right  battery cables and a electronic voltage regulator. They will prevent you from having a lot of issues in the future.

John J

 
Ah... morning discoveries under the air filter assembly.

Sure, doesn’t everyone plug a vacuum hose with an old screw? ?









 
Looks like the previous owner was in the "as long as it works" category wanna-be mechanic. That little section of fuel hose was just a fire waiting to happen, especially with that uninsulated glob of solder not far away.

Now you'll get to scratch your head (until you're as bald as me) wondering what/why did they do that? :)

It looks like you have a car that's in overall decent shape to begin your journey with, though. Good luck with making the car yours.

 
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A different angle on the carb/fuel filter.  What is this gunk at the top?  It's hard, like a solder.  Also looks like part was ground off then dunked over.  *head scratcher*

More concerning, have they done something to the inlet that makes this carb ineligible for a resto?



 
A different angle on the carb/fuel filter.  What is this gunk at the top?  It's hard, like a solder.  Also looks like part was ground off then dunked over.  *head scratcher*

More concerning, have they done something to the inlet that makes this carb ineligible for a resto?

Looks like some type of epoxy was used to "fix" a fuel leak.

 
But where is the Duct or Duck tape? It will never run without it.

Cracked me up when naked and afraid contestant took Duct tape, lol.

I was on the way to Tech School back in 1966 and had two guys that rode with me. About a mile from school the clip that held the throttle linkage on the carburetor broke and no gas pedal. We had nothing to tape it or wire it so one of them sat on the front fender with the hood open and worked the throttle while I drove and shifted gears, lol. Boy did we get some looks that morning, lol.

 
Engine harness probably should be replaced - this is the one NPD shows for 351C w/ auto trans

https://www.npdlink.com/product/wire-loom-engine-gauge-feed/146047/212876?year=1973

Agree with TommyK on the carb, epoxy or JB Weld to fix a weeping passage. Pretty common fix.

Most times a new fuel filter will come with a short section of hose and a couple spring clamps.

The wire looped around the A/C lines might be the compressor clutch power wire.

 
Tell me more about the wiring harness. NPD doesn't have much info about application. Is this the feed for the instrumentation, too? Oil pressure and temp seem to be fine, but as usual, ammeter barely moves -- either way. I'd agree with you the cut black wire might be the feed for the compressor, but the other end of the wire just disappears though the firewall, unprotected/unclad/unsupported.

Back to the carb: there is a leak right in that area, and it appears to be in/around the patch. What options for the carb does that leave me? Is it beyond a rebuild? And then the second question if the answer is "yes, beyond repair", replace with same or time to update?

Thx,

 
A carb shop should be able to fix that leak, or just replace the top cover, There's a plug there for the machining operation to drill the fuel passage.

The engine harness includes the gauge feeds (oil pressure/water temp), coil (+) feed, electric coil (+) feed, anti-dieseling solenoid (+) feed and A/C clutch (+) feed. The connection to the main engine bay harness is behind the driver's side valve cover, two flat plugs, typically 3 or 4 positions each. From the picture they post, it looks correct for a '73 to me.

Maybe someone hot-wired the clutch? Might be worth a peek to see where it goes under the dash. The factory clutch wiring was  clutch ->plug-> extension wire->plug->A/C (+)feed on engine harness.

Oh, attached 73 vacuum diagrams. The calibration code is the sticker on the front of the passenger side valve cover. It's visible in one of the pics from the eBay listing, clean it carefully if you can't read it.



1973_ServiceManual_Vol6_EngineEmissions_Mustang.pdf

 

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  • 1973_ServiceManual_Vol6_EngineEmissions_Mustang.pdf
    6.6 MB · Views: 13
To my knowledge nobody makes a complete harness for these cars. They make the alternator part but I do not think then entire harness back to the firewall. If they do I would be interested.

The carb would have to have a new top section and the 73 is unique to 73. One good thing would be that most of the trashed ones are due to the float bowls being corroded and no good but the top half might be good with the area broken on yours.

The kit for these carbs is pretty easy to install and set floats. There are videos online also. Be sure you get the correct one I got one from NAPA. I had ordered one from Mike's carb. and he sent the wrong one was not the spread bore. When I told him it was wrong he said I didn't give him enough information. I told him 1973 Q code 351 4-V but he said there were two carbs use but there was not. He sent kit like for some of the big Fords that had a 4300 but not the big spread in the back.

If you do change you might want to go with fuel injection for better mileage and performance.

If you live in California what are the inspection rules there? Do you have to keep the EGR valve? That is the plate under the carb and the valve is on the back.

 
To my knowledge nobody makes a complete harness for these cars. They make the alternator part but I do not think then entire harness back to the firewall. If they do I would be interested.

The carb would have to have a new top section and the 73 is unique to 73. One good thing would be that most of the trashed ones are due to the float bowls being corroded and no good but the top half might be good with the area broken on yours.

The kit for these carbs is pretty easy to install and set floats. There are videos online also. Be sure you get the correct one I got one from NAPA. I had ordered one from Mike's carb. and he sent the wrong one was not the spread bore. When I told him it was wrong he said I didn't give him enough information. I told him 1973 Q code 351 4-V but he said there were two carbs use but there was not. He sent kit like for some of the big Fords that had a 4300 but not the big spread in the back.

If you do change you might want to go with fuel injection for better mileage and performance.

If you live in California what are the inspection rules there? Do you have to keep the EGR valve? That is the plate under the carb and the valve is on the back.
Thanks for the rebuild tips!  And the auto parts store closest to me?  NAPA - bonus.  But yeah... will have to dive into fuel injection.  Besides what you mentioned:  reliability.

"Yes" to California, but vehicles past a certain age and/or odometer are exempt from smog requirements.  The year for that rule was when manufacturers finally starting using 6 place odometers ('86 maybe?).  Before of course couldn't tell if "32,565" was true or "132,565" or...

 
Good carb info - thanks.  Under consideration for the "while you're at it..." category, I might turn to fuel injection.  I'm remembering the knuckles lost changing spark plugs on my '71.

1,000 thanks for the vacuum diagram!  Old, dirty and faded, it's definitely hard to find colors or markings on these.  At least a few mysteries will be solved today.

And yeah, that might-be-compressor-clutch wire:  will chase down under the dash, for sure.  Half hoping it does lead to one of the two mystery switches -- I'll never know what they were for, but at least problem half solved.

 
Finally did something:  started on replacing the radiator.  Still waiting on the replacement shroud, so here's the first half:  remove.

I must have read the "tilt the shroud back and lift the radiator straight up" 20 times before I finally... tilted ONLY the shroud back.  There are two clips at the bottom, so hold down on the titled shroud and lift the radiator.  Helps to have help.

I went with copper/brass, metal side tanks, 3-row from ACP.  In black.  (lol)

But before the shroud arrives, I plan to pull the a/c compressor (eventually to be replaced in an R134a upgrade) and the power steering pump.  Having much anxiety about that pump!  By the time I acquire all the equipment to do it myself, and enough beer, I might be better just replacing.





 
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