1988 festival stuck idling high

[EricksonJ]

I'm sorry, I didn't notice your posting 12 before I commented last. I usually never take the car out of gear, but I was traveling from Tennessee into Asheville NC, and there is a huge mountain and a pretty high speed limit. I just didn't want the engine to have to run that hard for so long while I was going down the mountain. I had no idea it could cause a problem. I checked the choke plate and it is open where it should be. As for the idling, it is super high. It sounds like the motor usually does if I'm on the interstate running 60 mph. Thanks again everyone, I really appreciate all the help.

[Rick the Quick]

Your engine is not running hard while in gear and going down hill. Keeping it in gear will keep your speed in check. Free wheeling / coasting is literally like a run away freight train. As for you idle speed as you described, it doesn't take a lot of throttle opening to produce 2,000+ rpm's in nuetral. It does not sound like a mixture problem. It sounds like a mechanical problem such as no freeplay in the throttle cable or a problem with the fast idle cam. The fast idle cam is what (when properly adjusted) increases the idle speed when you first start the engine on a cold day. Actually this is one item that would benefit from cleaning with a can of spray cleaner. If you look at the choke plate you will see one end of it connecting to a rod / link that is responsible for turning a cam that in turn raises your idle speed with the choke in the partially closed position. It will make sense when you look at it. If it's all working correctly you should be able to (with engine off) hold the throttle wide open, close the choke valve and observe the cam rotating to where it will raise the idle speed. When you open the choke you should be able to see the cam rotate to a position where the idle speed should decrease. The pivot point where the cam rotates could get dirty to where the cam does not rotate freely. This is where you would want to blast the carb cleaner. It has been about 8 years since I had a Festiva with a carb so the procedure I describes may not be exact. It will be valid with probably the great majority of all vehicles with a carb and automatic choke and BTW this is just one of the reasons that we haven't used carbs since '88 or '89. One other thing comes to mind and that is any type of so called dashpot that is designed to keep the throttle from closing to quickly. It will be a pod like device with a rod and a rubber boot/ accordian looking thing coming out of one end. The rod is designed to engage the carb linkage to prevent the throttle from closing too fast. These dashpots some times need to be adjusted or removed to get the throttle from being held open. I will probably hear from someone saying that you will cause all kinds of problems by removing it such as damaging the throttle plate by allowing it to slam shut (what about the 60 years or so that carbs didn't have dash pots?) but in the interest of drive -ability and smooth shifting you should look into or try adjusting the dashpot to where it has minimal effect on holding the throttle back as it is wanting to close.

[EricksonJ]

It seemed like everything was moving when I pulled the throttle cable today. And there was about 1/4 inch of play in the cable. I started it and couldn't see any fuel through the viewing port on the carb. I left and went to school. Got home and I could see gas about half way up in the viewing port. Started it and left it running. Went around and looked at the viewing port and couldn't see any fuel. Does it sound like the carb isn't working properly?

[bravekozak]

Did you already check if the rubber line under the fuel tank is collapsing with the engine running?
Disconnect the fuel line and blow compressed air through the fuel lines.

[EricksonJ]

I Changed the fuel filter today and was able to blow air back into the fuel tank

[Rick the Quick]

If you can't see any fuel in the carb you can disconnect the fuel line at the carb and put the end of it in a clear container where you can observe the fuel flow while cranking the engine. Before you crank the engine you want to remove the coil wire at the distributor cap and ground it. This will be the center wire going into the distributor cap. Make sure the metal end of the wire is securely attached to ground as fuel vapors and sparks will cause an explosion. Ground can be a strut bolt that sits on top of the strut tower. Not the big nut in the center but one of the smaller ones to either side. Have an assistant crank the engine while you observe fuel flow. I am not sure what the service manual calls for but it should fill a 12 ounce bottle fairly quick. If it passes the volume test you will want to connect the fuel line to a pressure gauge and crank it again. I believe it should put out between 5 and 7 pounds of pressure (psi). You can probably find an inexpensive vacuum / fuel pressure gauge for $20 or less at Auto Zone or Harbor Freight. Of course if you buy one for $20 or less it may not be the most accurate gauge available. If the fuel pump passes volume and pressure test there may be a problem with the float circuit. Like your buddy mentioned it may have a stuck float. I have encountered stuck floats on cars that have been sitting for a long time. They can stick in the down position which will cause flooding like you can't imagine or they can stick in the up position like the MG 1100 I bought cheap because the mechanic said it needed a head gasket. It had dual SU carbs one of which had a stuck float in the up position which will not allow any fual to enter the float bowl. How did I fix it? A few taps on the float bowl did the trick.

[WmWatt]

Hello again. I searched this site on "fast idle" and read some of the posts. You could go around wiggling hoses and links while the engine is running to see if anything makes a difference. You could also get a plant mister and mist the engine in various places while it is running. If any moisture is sucked in through a leaking hose or gasket the engine will temporarily slow down, ie 'bog". It's best to do that after coming home from a drive when the engine is at normal operating temperature, ie, warmed up. Also to my understaning a fuel restriction would cause the engine to idle slow, not fast. I'm not trying to contradict what has been posted, only to save you taking the engine apart trying to fix the problem. I'd save that as a last resort.

[EricksonJ]

Still trying to get this thing running right. I have had a few people tell me it could be the IAC valve. Does that seem possible? Also where is the IAC located? Also, where is the choke plate located that could be sticking causing the car to run on the high idle cam? Once again, I am kind of new, and I was looking at the butterfly valve in the carb, thought this was the choke plate that was potentially sticking ��

[tooldude]

The choke is at the very top of the carb covering half of the opening (primary venturi). Check for the throttle plate on the other side (secondary venturi) closing after a fully open throttle. If the fuel is not staying mid-level in the fuel bowl sight glass, watch from startup to see if it's going down (fuel starvation) or going up (flooding/over-filling the fuel bowl).

[tooldude]

BTW, there is no ISC Valve on the carb engine - that's on the fuel injected engine.

[WmWatt]

^^ probable typo ISC = IAC

[EricksonJ]

Where exactly is the throttle plate on the other side?

[tooldude]

^^ probable typo ISC = IAC

Yes, a typo, from using my phone. Meant IAC, thanks WmWatt.

[tooldude]

[QUOTE=EricksonJ;754821]Where exactly is the throttle plate on the Throttle plates for both venturies are at the base of the carb. Look straight down into the carb (with light) and you will see throttle plates at the bottom.

[EricksonJ]

Update: when I start the car the fuel level looking through the viewing port goes all the way up. Also, the front choke down in the carb is staying closed. I'm pretty sure it looked like the back choke stayed shut too. Couldn't tell for sure tho