Vintage Cars: 1985 T-Bird V6, vapor lock, poor fuel

Question
QUESTION: I have a problem with the car coming to a stop or accelerating. It seems that when I come up to a red light and take my foot off the gas, the motor with jerk about 5 times before smoothing out again. Then when I accelerate from the light, the car will hesitate to almost stalling. I have to step on the gas to keep it from stalling. The result forces me into the intersection at a high rate of speed. If I tap the gas and let off immediately WITH the brake on, the car will stall.

ANSWER: Hi Ron
Sounds like fuel delivery.  How long since it has been serviced, how many miles and did this come on suddenly.  all this will help to diagnose problem. This could also be an electrical problem or sensor issue.  More information will help me help you!


---------- FOLLOW-UP ----------

QUESTION: I'm sorry for not being through with the problem. The car has had this problem for several months. I have done a complete tune-up including replacing to O2 sensor thinking that was the problem. I was thinking it might have something to do with the ISC but at $100 + and non returnable, I didn't want to take the risk of replacing it. The car has 126k miles. The engine is like new. Been well taken care of. It rides very smooth down the road and gets almost 20mpg. The problem will not appear until the car has been drive for about 10-15 miles. I hope I have given you enough info this time. Thanks again for your time.

Answer
I have heard that the 80's t birds had trouble with  an iginition timing module I would check and perhaps replace that, should be on or around the distributor. They are not too expensive.  If it develops only when hot you may be getting a fuel vapor lock, check your gas cap and make sure it allows for air to flow.  Are the fuel filters clean?
Unfortunately you may need to check it at a Ford dealer to see if it has thrown a code, or has poor fuel pressure.  Some other diagnostic tests may be needed as you may throw money into parts and not hit the target.
Sorry but poor idle and stalling can have many causes. Let me know what you find
Ron