1984 5.0 throttle body convertible stalls when warm

[velocity5]

Car starts and idles perfect for 10 minutes. Before the thermostat even opens it then surges and blows black smoke. It smells rich and dies. I have to hold in the throttle to restart.
Long time owner states it has been looked at years ago and nobody could figure it out. She just puts it in neutral at stop lights to keep it running.
The car is in great shape otherwise. All emission hoses are there and hooked up. Where should I start?

 

[90sickfox]

Is the engine coolant sensor hooked up ? What year is your car ?

 

[General karthief]

84 with a throttle body? Is it cfi or was it converted?
maybe a picture would help.

 

[velocity5]

84 with a throttle body? Is it cfi or was it converted?
maybe a picture would help.

Car is factory. Sorry I don't know what cfi is. It looks like this but no a/c .

 

[velocity5]

Is the engine coolant sensor hooked up ? What year is your car ?

1984. Everything appears to be plugged in.

 

[General karthief]

Yank the air cleaner off, I think you will find a carburetor under there.

 

[velocity5]

I am going out of town for a week so I will check it when I get back. I always thought it was a tbi. It always starts right up cold without pumping the gas.

 

[General karthief]

Let us know when you get back, we can start with a choke adjustment.

 

[Mustang5L5]

If it's a 5-spd it's a carb. If it's automatic, it's CFI. Really need to know what we dealing with first. Pictures help


CFI will say EFI on the valve cleaner. Carb will say 4V like the pic above

 

[velocity5]

I am back. Thanks or the help. I will check it asap and take a pic

 

[velocity5]

If it's a 5-spd it's a carb. If it's automatic, it's CFI. Really need to know what we dealing with first. Pictures help


CFI will say EFI on the valve cleaner. Carb will say 4V like the pic above

Looked at it today. It says EFI like the above pic. it is an automatic.
Owner informed me the catalytic converter was removed years ago. It also has had 2 brains swapped out trying to fix the issue.

 

[Mustang5L5]

So it's CFI.

Which means it's eec-4 and you can pull codes. Locate the test plug which might be on the drivers rear of the engine bay near the wiper motor.

There's a sticky at the top of the tech page explaining how to pull codes. You'll need to use the test light method, or buy an innova 3145 meter for $20.

I'd locate that test plug first