QuestionQUESTION: I recently bought a 1968 Plymouth Satellite 318 V8. I enjoy driving the car on special (sunny day) occasions. The car starts fine runs well, but when the car is warmed up (after about a 4-5 mile trip) and I put it in Park, the idle runs very high. When I put it back in Drive, the idle runs fine. I know a little about adjusting carbs so yes, I have tried to adjust the idle to run adequately in Park, but when I do so and then when I put it in Drive, the idle runs too low and it stalls. I had to choose the lesser of two evils and keep the adequate idle adjustment for the car for normal idle when it is in Drive. The car has a holley carb with a manual choke. I purposely double check to make sure the manual choke is off when I make these adjustments, but the idle still runs high. I took the air cleaner off and made sure the choke components are working fine. I have no idea what's wrong, but it has something to do with the amount of fuel that this carb is delivering warm vs. cold. Any suggestions?
ANSWER: I did not realize from your first question that you are not getting fast idle when the engine is cold. You should be - the fact that it is not as high as you get when the engine is warm adds to the confusion - and I can't explain it other than to suggest that the fast idle cam is not set right on your manual choke.
The car came with an automatic choke, so apparently the carburetor is not the original - perhaps something isn't correct in the linkage to the fast idle mechanism.
It is possible that the vacuum choke pull off diaphragm is no good, or is connected to the wrong vacuum source, or is totally missing or not adjusted properly. Since I don't know whether the car has the right carburetor on it, we're shooting in the dark here.
However, none of this changes the fact that putting the car in gear when it is warm causes it to stall unless the idle speed is set high. This still means that there is a problem with the engine state of tune or condition - so work on fixing that and then we'll see what symptoms are left after that is cured.
Dick
---------- FOLLOW-UP ----------
QUESTION: You are right - it is not the original carb. (I bought this car this way, with an oversized holley.) The fact that my car has manual choke almost drives me crazy, but I want to see if I can get it right before attempting replacing the carb. You suggested that the fast idle cam is not set right on my manual choke. I'll bet it is not set at all. My manual choke only moves a steel diaphgram on top of the carbuerator. The fast idle cam suggestion may be steering me in the right direction. What is a fast idle cam? Does a carb (disregarding the choke diaphragm)somehow change the amount of fuel intake when the engine gets warm? Any information/suggestions you can offer is appreciated.
Thanks.
AnswerHi, George;
Your transmission fluid is not a very likely candidate for the cause of this problem. If the fluid is red in color, and doesn't smell burnt, it is very unlikely to be too thick or sludgey. Transmission fluid is just vegetable oil, and it doesn't have to deal with combustion products, so it stays pristine for many years and many thousands of miles, unless the transmission is in such terrible condition that debris is being cast off by worn out parts. So, look at and smell the dipstick - if it looks and smells OK, it is OK.
Thanks for the kind words - and you are welcome! I do this job because I get the reward of good feeling when someone gets their car straightened out without a lot of unnecessary expense and trouble.
Dick
