Ford Forums banner

1973 Thunderbird 460 dies after a few minutes

6K views 12 replies 3 participants last post by  CatSkinner 
#1 ·
OK, here goes. I bought this car early this summer and drove it about 1000 miles to my home. The previous owner sold the car on behalf of a friend's estate and didn't know much about the condition other than it hadn't really been running much in the past number of years. He had the original Autolite carb rebuilt along with a new fuel pump, points and cap. About half way (500 miles), after really having no engine troubles (86,000 miles on the car) I heard and felt a minor hesitation that only occurred once. I had refilled quite a few times, as you can probably imagine, so I don't suspect I still had bad gasoline, if I even did at all. Maybe I had some ethanol in the mix with today's gas, I dunno. Anyhow, I kept driving and as the next 500 miles went along the car started to hesitate, miss, and back fire more and more. The last 200 miles were nerve racking. The car really wasn't happy. I did actually get it home and it died in front of my house. Yes, 1000 miles just to die at home.

Since then, I've replaced the spark plug wires and vacuum advance (which was certainly shot), but the car will only run for a few minutes and then all of a sudden sputter and die in my garage. I wouldn't even say it gets to temperature before it sputters and dies. Even playing with the gas peddle does nothing to keep it running anymore. I'm too scared to take it out on the road. I did a fuel pressure check by removing the line from the carb and fill a glass jar and it seems fine. Although, the fuel is yellow as urine. Is that ethanol in the mix? I got a jerry can full of premium and added it to the tank, but still no improvement. The fuel filter is clear. The timing seems fine, although new timing belt and gears probably wouldn't hurt, but I don't think that is this immediate problem. People talk about vapour lock and bad coils. Any ideas out there?
 
See less See more
#2 ·
You will have to try and find out if it's electrical or fuel fault causing the problem .If it has points as you mention , may be the condensor .Check if points are blue indicating burning and knacked condensor .Could even be the fuel pump that was replaced full of s*** or the diaphram failing .
 
#3 ·
The symptoms seemed to progress the longer you drove, parts of what you described seemed almost symptomatic of sticky floats, but for a car sitting as long as yours, I'd expect it to act up immediately, not progressively get worse.

When I'm troubleshooting a neglected piece of equipment, the first thing I prefer to do is bring the maintenance up to date. Vacuum is the primary controller of your car, replace the hoses, caps etc. for the vacuum lines (include the grommet for the PCV valve, you'd be amazed how much they can leak even if they look good). You said you all ready replaced the plug wires and vacuum advance, change the plugs, points, condenser, etc., then go back in and see what issues are left. Trying to diagnose an engine that needs the routine maintenance performed on it has too many things masking any real issue you may have.
 
#5 ·
Sorry for the delay, I needed to paint the house (exterior) before while the weather was good. So, finally got to a few things on my TBird...
- Vacuum: 20 psi. Pretty steady
- Compression: 110-125. 3, 7 and 8 are at 110
- Coil: primary 2 ohms, about 8000 on secondary. Seems to be correct.
- Plugs: AC Delco R44T, gapped between .32 and .35. Although, they all seems to have oil on them and the electrolyte is dry. Maybe head gaskets? Would that really cause this, or is it something nice to change later? Picture attached.
- Fuel pump: disconnected at carb and cranked to fill a jar. Seems to squirt with decent volume
- Autolite 4300 carb: screwed both idle screws in till minor resistance, then backed off 1-1/2 turns. Haven't moved them since.

Still starts, but sputters a few minutes later. Not always the same, sometimes takes longer to act up, other times earlier and yet same 20C/70F outside temp. I still kind of suspect a fuel delivery problem. I'll take out the pre-fuel pump filter that the other guy put in and return the fuel line to normal tomorrow and see if that does anything. I did buy some Seafoam and sprayed into the carb, oil and fuel. Everyone raves about it. Maybe, but no difference. Through a bunch of 91 octane fuel in too
 

Attachments

#6 ·
ANSWER: 1973 Thunderbird 460 dies after a few minutes

OK Fellas, got it fixed. There's a guy in town known for being able to fix these old Detroit iron cars. He came over yesterday for a quick visit and listened to the car and said it sounds more electrical/timing than a fuel problem. He said those spark plugs are really ok being a bit black, and that with the car running rough and rich - that'll darken the plugs. He came today and first adjusted the dwell (was about 20, put it back to around 26). Then re-adjusted the timing to 14 BTDC (as per the sticker on the valve cover. Car ran a bit better (smoother), but then started to sputter and die. He reached into his bag and pulled out.....


wait for it .....


A replacement COIL. He said even though it tested fine, it could have an internal leak that acts up. We replaced it, and the car runs great - no hesitations, no sputtering, no stalling. So there it is.... COIL! (Sure glad it wasn't the timing belt, yeeesh!)
 
#9 ·
1973 Thunderbird 460 : Ignition Conversion Kit Works

Hi Cat. Stalls both at idle and under load. But, I did get an ignition conversion kit (Pertonix II) and put it in. I haven't had it stall since. Not 100% convinced, but hard to argue with results. It's funny since I don't think anything was wrong with the points or condenser. Maybe there was too much voltage to the condenser and it was acting up. I dunno. But, she's up and running. Thanks, all.
 
#12 ·
Actually, back to stalling, or near stalling. I've barely driven it this summer, and after 10 minutes started running rough again like it's trying to run out of gas. But when I open up the throttle it accelerates. Also, it is idling, but rough as well. Maybe I should just ditch the Autolite carb and get an Edelbrock or Holly. Any suggestions?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top