Crazy high idle!

[King Zarkon]

Hey everyone!

So I was driving today, and as I was going I noticed that the idle kept climbing and climbing. It climbed to the point that I was doing 50mph without touch the gas as I arrived at my destination.

Shut the car off for a few minutes, then fired it back up and it was revving out hard, as of it were floored, without touching the pedal.

Under the hood, the throttle isn't sticking, nor is the pedal. Do I have a likely vacuum leak? I've got a 360 with a quadrajet if that helps.

I can only park where I am for the night so I either need to get this worked out or call for a tow!

Much thanks in advance for any guidance.

[babywag]

very the throttle is actually closing all the way?

other possibilities loose distributor and now waaaay advanced?

[King Zarkon]

Yep throttle is closing all the way. I'll check the distributor next. And chance something in the carb stuck open?

[78 WIDETRAC]

Is there anyway you could post up a pic? Are the springs on the cab linkage present?

[bufurd]

A Q-jet, good for you, best carb there is. I'd lean towards an intake issue over a timing issue. First thing I'd check is that the carb is tight, caution, overtightening is what kills most carbs. Second thing would be the fast idle mechanism, related to the choke it can hang if not properly set up. Make sure the secondary isn't hung, a possibility is the little arm that protects things by not allowing the secondary's to open until the choke is completely open. I remove or bend it out of the way to eliminate it as it's just something to hang when you wanna rip. If all that checks out a can of starting fluid sprayed around carb and intake while running to check for leaks would be next.

[wiley-moeracing]

Sounds like your leaking fuel from somewhere, check down the carb when running and see if you have a float stuck, or on the quadrajets also will develop leaks at the hole plugs in the carb( which is why you see epoxy to seal them up).

[King Zarkon]

Ok so I took another look and couldn't see anything obvious (to me) but I made I little video with the hopes that you all might see something

https://youtu.be/Xdp1Pro2iGc

[King Zarkon]

One more thing - I neglected to mention that upon shutting the engine down yesterday, there was a pretty loud backfire.

[78 WIDETRAC]

Have you fired it up today? And with out the air cleaner?

[King Zarkon]

Yeah it was exactly the same. Started revving super high right away.

I didn't run it without the air cleaner though, should I?

[babywag]

Yep throttle is closing all the way. I'll check the distributor next. And chance something in the carb stuck open?

Did you disconnect the throttle cable @ carb to make sure the throttle plates are fully closing?

While rare, I have seen a cable fail on more than one vehicle that prevented full closure of the throttle plates.

[King Zarkon]

No, but I will try this just now. I've got no cell signal down in the parking garage where I'm working on it, so I have to come back upstairs to check these replies haha

[78 WIDETRAC]

Little late now, however I wouldn't run it with out the air cleaner. I does sound like the distributor possible rotated, or something is up with the throttle cable.

Update us on what it was when you find out.

[King Zarkon]

Ok - soooo...

I went to get some supplies and waited 2 hours in line. All of the stores are closing and today was the last day they're staying open so things were a little crazy.

I got back, distributor is tight. I took some PB lubricant and sprayed a tiny bit on each of the obvious moving parts on the carb. Refitted the air cleaner, and it started up as usual. A little high for a minute or so, tap the had and it comes down a little, tap the gas after another minute or so and it seemed to be idling like usual.

I let the engine warm up for about 5 mins, and went for a 20 minute drive including highways and city streets. No issues at all. Seems ok. Hopefully it stays that way.

Question - is it possible that the choke was sticking? I'm fairly new to working on cars, but have been working on motorcycles for the past 6 years or so. Had a similar issue with the manual choke on a bike. Not sure how automatic chokes on cars work though, so forgive my ignorance.

Many thanks for all of your timely replies!! I'm sure I'll have a new thread to start soon! (Barring having to restart this one)

[bufurd]

That's how a carb choke works, as engine warms up the choke opens and at the same time backs off on the fast idle when ya tap accelerator. Really shouldn't use any type of lubricant on the linkages it'll gum em up, sprayed off with carb cleaner is best. If ya have any trouble with that Q-jet, I can shed a lot of light on what it wants to be happy..