I purchased a 1970 Maverick (see my picture) with the 250 straight 6 back in November - love my car - this problem used to happen occasionally and was never too big of a deal but it scared me a bit this morning when it was icy. My attempt at describing it: Cold start - either in the morning or after work HIGH idle in park or neutral - sounds like I have my foot on the gas pedal (we checked the throttle so I don't think anything is sticking). On particularly cold mornings like this morning (in the teens) it'll rumble a bit before starting to whine. When I shift into gear the car sounds normal but will go about 30mph without me pressing the accelerator. Braking is obviously a bit tougher as the car WANTS to go go go. After a bit - maybe driving .25 miles of stop and go - it chills out and drives normally. Reason it scared the crap out of me this morning was my street was icy so rather then being able to ease out of my parking spot I had to slowly ease off the brake - and the brake had a hard time stopping the tires from spinning on the ice at the stop sign. I think it could be a vacuum leak...sound plausible? Any easy way to confirm or rule that out? Supposed to be sunny and 60 this weekend so I would like to take advantage of the weather.
The choke will engage the high idle cam when cold, sounds normal to me... Warm it up awhile if it bothers you...
Thanks for the quick response! What about the acceleration once in gear - would the same thing be causing that to happen or are these two entirely separate issues that tend to happen under the same circumstances? Also the car continues the high idle whine in park or neutral for as long as I'll let it (usually 5-10 minutes) but sounds "normal" not high rpm while in gear.
Till you "blip" the throttle a time or two after it warms a bit, will continue to idle fast... Makes no difference if in gear, engine will run fast till it warms and fast idle cam is released by choke opening, just the way carbs operate(at least if they have a operating choke)... BTW... Welcome to the 20th century...
Thank you - previous to this car my choke experience was limited to lawn mowers and boats. Happy to know it's just warming itself up (although my neighbors may be less happy that this morning routine going to continue/lengthen until the weather improves)
If I correctly interpreted what you wrote , five to ten minutes on choke mode is far too long!!! You should be able to bring that choke system down off high idle after one minute if you tap the throttle a couple of times. If not, something is hanging up or not adjusted correctly.
I agree with Hotrock. Mine would do this when the choke was adjusted too rich. When it got real cold, it just would not come off high idle. With the engine cold, unscrew the three screws holding the black cap. There should be a couple of marks on the cap and the carb. Turn the cap counter clock wise a couple of marks. Also, look at the fast idle screw to see if it is adjusted in too much and make sure the linkage is not binding. Micah
He stated it idles down after a 1/4 mile, sounds normal to me... It'll never come off fast idle till it warms a minute or two, then a blip of the throttle will release the fast idle cam... If the throttle isn't tapped, it'll idle high until it is... ..
Tom, You might be right on that. Just seemed that before a 1/4 mile, he should have opened up the throtle enough that it should have come off the high idle. Micah
That's what I was thinking - It seems like it should settle down sooner. On a day when I have to scrape off the windows etc I'll do all that, go inside get a fresh cup of coffee, come out and it's still sounding like an airplane ready for takeoff. Also it doesn't sound happy when it's doing the high idle - it's a very high whine like I am pressing the accelerator. The first time it happened I tried to tap the throttle a couple of times thinking something was stuck - but nothing changed. Anyhow I appreciate all the feedback and I will take a look this weekend at the choke - it's supposed to be warm and sunny! - Kelly (I'm a she not a he for future reference but no worries)
So noted... When choke is activated by temperature, engine will continue to run fast till the choke has warmed enough to allow the fast idle cam to release when throttle is bliped... No blip, it'll still run fast till it runs out of gas... As has been mentioned it's possible the choke is too rich, so doesn't release the fast idle as soon as it should... Adjusting the black disc(housing) on the side of carb slightly counter clockwise will allow a quicker release... There are three screws around the housing that must be loosened before it will turn... Make a note of where it's currently set in case it isn't happy with the new setting(wont idle without dying when cold)...
Be sure to check that your choke heater tube is in good condition and still attached to the exhaust manifold. The manifold heats up the air inside this tube which in turn heats up the bi-metallic clock-spring inside your choke which will flip the choke open and off of high idle once you give the pedal a blip to release the high idle cam. The later cars had an electric choke which used electricity to warm the choke spring. It just sounds like the choke isn't opening after it's warmed up. You could also remove the air cleaner cover and verify whether or not the choke is opening after the the minute or so and the throttle is blipped.
