65 mustang engine question

It sounds like your carb's float is stuck. Black smoke indicates an over rich fuel mixture. By the way, your car is either a 1964 1/2 with the 170ci engine or a '65 with a 200ci. Check the fifth digit of your VIN. It should be a U for a 170 in a '64 1/2 or T for a 200 in a '65. Unless, of course, you or someone else installed a 170 in a "T" code '65.

Oops, Disregard that last statement. You said it ran fine when warm. It sounds more like an issue with your choke. Either way, it's your carb that's acting up. :)~

"Patriot" wrote in news:UoednRbPP6cYRajZnZ2dnUVZ snipped-for-privacy@comcast.com:

Sure sounds like the choke is staying on too long?

I'd start with testing the choke pull off..... It may not be holding vacuum well or it may be adjusted too "loose". Other considerations include the choke stove... it may not be warming the chokestat quick enough (the bimetal spring under the black bakelite cap).... possibly a reluctant heat riser valve in the exhaust.

While the automatic choke may seem to be complicated (the favourite fix is to throw our arms in the air and install a manual system - usually a bad move since the carb isn't design for manual choke operation), it is a set-up of simple systems working together..... To effectively repair an automatic choke and bring it back to "as new" operation, it is essential to understand the subsystems.... Your local library can probably help. While terms like choke pulldown, choke break and pulloff may sound daunting, all of these actions are simple and happen for easily understood reasons.

Get a grasp on Bernoullis principal, check some of the automotive or carburettor basics type manuals and, in no time, you should be the expert.... honest. If I can figure it out, anyone should be able to if they have the desire.

When the engine is cold and you step on the gas to set the choke, check to make sure that your choke plate is slightly opened. If the plate is completely closed the engine will start right up but after a few seconds, when it uses up the available air, it will start to run rough. After the choke starts to function, and it gradually starts to open the choke plate, the problem goes away. Also if your engine is not getting enough air, at start up, the air/fuel ratio is on the rich side thus the black smoke.

Hope this makes sense!

"Patriot" wrote

Sounds like the choke just warming up. That's what I would expect.

Is it black or just wet? the condensation in the pipes is gonna be forced out and splatter on the ground. The other thing it could be is unspent fuel from when the engine was running rich while the choke was closed.

I think you're overanalyzing this early in the game.

Two things ,,,,the choke is probably loading up. Here is a quick primer on a choke ,,, it should be shut tightly when the car is starting ,,then it goes to "pulldown" which is typically no more then a 1/4 inch slot of opening(even less),,,then the choke slowly pulls open from there. If the pulldown setting isnt open enough the car will "load up" ,,which essentially means its running way to rich. If the setting is too much the car will die after starting. Pulldown specifications are published and the way to adjust them varies with the carb. Its usually a vacuum diaphragn that opens the plates to "pulldown". Sometimes just turning the choke cap one notch leaner will help but the choke cap really only controls how fast the choke comes off after pulldown although it does control the plate tension. You have to find the adjustment to control pulldown. Have someone else start the motor while you watch with the air cleaner off,,, you will see the carb go to "pulldown" and you can then trace the linkage and see how to adjust it. The other possibility is that your valve seals are shot and you are leaking oil past the seals into the combustion chamber at startup. You can usually tell if your running rich ,,,, or burning oil ,,,, rich is black,,,, oil burns with a white smoke. Steve ex ford engineer

Hey Guys, thanks for all the great responses. After reading your replies, I went out to start the car and check the choke plate. With the air cleaner off, I looked at the choke plate it it looked half open. I then started the car, started right up as usual, idled fine for about 3-5 seconds and started the rough idling. I jumped out of the car and saw that the choke plate was completely closed. I reached in and opened it about half way and it began to idle very smooth, I let go, the choke plate closed again and it began idling rough again. I will do some reading on making an adjustment to the thing or further testing of it, and let yall (> changed the oil a few weeks ago and it was still full on the dipstick