Winter Idol/Idle

[AmpTrooper]

Hello y 'all,
Its been a while. We bought a house and have been doing a lot of work on it. Things are pretty good now. Still have some projects but, thee will always be projects with a home that is 113 years old. Good to own a home again though!

Okay so, my 1983 Cont. is having a winter issue. I have looked up but found conflicting info. So i though i would pick your brains. She works fine in temps over 40 under that, what happens is the idle runs fast as it should to start but does not slow down once it has warmed up. I have had to drive it that way for over 45 miles and it was still running full blast. Also, when it does this it has isses starting as if the battery is not getting a proper charge. If i have it parked and wait a sit and keep lightly tapping on the gas i can sometimes get the idle to slow down and idle at normal speed. Again, above 40 degrees and it runs perfect. This car has been in Florida its whole life. This is the first real full winter with low temps that it has ever had. I do not drive it much in the winter but the few times i do i dont want it running like this as it an cause a lot of wear on the engine.
Any thoughts? I have my ideas but this one place online basically said that was not it. So, i need more heads on this so i can get the right part. I would like tobfix it this weekend as it is going be in the 50 s this weekend! It can stay that way too! Thanks for your help!

 

[tixer]

Hey AmpTrooper! Welcome back, and welcome to the "This Old House" club. (89 years old, here..)

I think I've got an idea on your car, but it will require a bit more research on your part. I have two theories for you..

My '86 does the exact same thing in cold weather. All of these cars have a "high idle" that is intended to make it run fast for the first few minutes of operation. In cold weather, it seems to stick. On mine, (which is a totally different animal, I'm afraid. 302ci with EFI) there was a second throttle cable that seemed to operate this function. It was connected at the throttle body by one of those "ball and clip" deals. I simply got in the habit of disconnecting it in the winter, and life went on.

Theory number 2 is that your throttle cable itself may actually be slightly frayed inside the cable housing, or simply hanging up. This is worth checking immediately, and has the potential to be quite dangerous. It may need to be replaced, or just lubricated. I would try disconnecting it at the engine, and checking to be sure that it moves freely.

I would not be surprised if others here have additional thoughts, but that's what comes to mind first. Please keep us posted on your findings!

 

[billcu]

I had an early 80's Cavalier that wouldn't idle down, it turned out to be a bad engine temp sensor.

 

[driller]

Welcome back friend!

I thought I remembered your car having a carburetor vs. fuel injection and a quick peek back verified this.

I would suspect a problem with the electric choke (if equipped) or a vacuum dashpot. If someone adjusted the carb without making sure the choke control system was functioning, they could've tuned the carb to where it would start and run properly in moderate temps but no so much in cold idle.

 

[AmpTrooper]

I dont think its the cable because like today when it is warm out everything works perfect. Y'll have given me some ideas. There is a part that i cant remember the name of it but, it is part of the throttle. It has a spring in it and is what kicks down the idle. Think i am going to remove it tomorrow and see if that is it and if it is i will get a new one. I hope that is it!

 

[AmpTrooper]

Okay, here is a new twist to this whole thing. If i put the heat from vent to defrost or dash, basically in the AC zone the idle kicks down and runs fine however, the heat tjen runs intermitently. The ac compresor kicks on but it comes on and everything works for a second then it makes a click and the clutch on the ac flips open and it stops for a second. It continues to do this as long as it is on heat and fliped over to the same area as the ac would be, that is in dash or defrost heat. Again, if i dont turn it to the defrost or the dash vents then i jave the high idle problem but, only when the temp outside is below 50. Seams very odd to me!

 

[budpytko]

Again - sounds like a vacuum leak to me..... ya just gotta FIND IT. The blower going to the default defrost mode is the biggest clue.

 

[driller]

Sounds like Bud is right. If the HVAC controls are vacuum operated, it sure sounds like you are introducing a vacuum leak depending where the controls are set. Could be a bad vacuum line or simply a bad vacuum motor on one of the actuators.

You may want to try to find the vacuum source going to the cabin and disconnect it and plug it on the manifold side.

 

[AmpTrooper]

Any particular line you would recomend as a starting place?
You know, that may explain my ac problem. It works intermitenly. It will blow cold for about a 3 count and then blow from the outside air for about a 10 count and does that over and over. As i am driving with the ac on it causes the engine to react as well. It feels like the car slows down just a very little bit when the ac kicks on. Then it runs fine when it kicks off for 10 seconds. I would imagine that all this is part of the same issue?

 

[driller]

I would imagine that all this is part of the same issue?

Very well could be.

First step I would take (lacking any factory manual/diagrams) would be to track down and trace every vacuum source and routing. Draw a schematic for future reference. At every branch in the vacuum line, be sure to trace it to it's respective end device (solenoid, actuator, valve, etc...).

IF the HVAC control is indeed vacuum operated (which I would highly suspect), there should be a vacuum line leading to the interior via the firewall. Usually there is a vacuum canister and check valve along the way.

Here is the Vacuum Diagram for '83 Lincoln Towncar w/ 350:

http://www.justanswer.com/car/0zl11-find-diagram-vacuum-hoses.html

Once the suspect line is located, inspect each for any cracks or leaks. A Mity-Vac hand pump is very helpful identifying leaks and verifying vacuum actuators.

 

[AmpTrooper]

Okay, after messin with it a bunch on my own and in this bitter cold i just cant do it becuase of my hip and lack of a leg. The cold and some of tue positions i had to get in to locate some of the lines is just too much right now. I think since i do have a trick to keep it running normal or close to it for, its best to wait till it is warmer. If it still looks like to much i will take it to the amazing auto shop i found who not only are experts with classic cars but thier prices are classic too! Got lucky with them for sure! I will taoe that diagram with me. I am sure they would like to have that anyways. Good info for sure!

 

[driller]

Good luck and keep in touch!