67 is running rough and will not idle
 

My ’67 is running rough and will not idle.

Life got in the way and it would up spending about 14 or so months without being cranked. Needless to say when I did try to start it, it did not go well. It cranked after a while but would not run below 1500 rpm. It was starting and running fine before it got neglected. I figured I had a case of old gas.

I have drained the fuel tank and replaced the Fram inline filter (G15). It starts easier now, but will not idle, will only run about 1000 rpm or higher. It will only start when the choke is pulled out. The carb is an Edlebrock 600 with a manual choke, fairly new about 2 years old.

We played with the timing and that did not seem to help, but did hurt when turned too far.

Could the old gas have gummed up the insides of the carb? If this was your problem, how would you troubleshoot it? Do I need to pull the carb?

Re: 67 is running rough and will not idle
 

You called it!!
It's the craptastic fuel.
Rebuild the carb time.

Re: 67 is running rough and will not idle
 

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Check the bolts holding the carb to the intake and make sure they are tight. Also check all of the vacuum hoses and make sure they are connected on both ends and not dry rotted.....

LockDoc

Re: 67 is running rough and will not idle
 

Will do, thank you.

They say the mind is the 1st thing to go... Is their something I can spray around the intake / head gasket (after checking bolts) to help detect a gasket leak?

Re: 67 is running rough and will not idle
 

For a bigger leak carb cleaner or a propane torch will help you - you can just turn the torch on (not lit of course) and let the propane flow to the carb base and so on. Or spray the carb cleaner around the base. Don't forget to turn the torch back off when done...

In either case if there's a substantial leak it'll pull that combustible material in and the idle speed will change, or you'll hear the engine respond at least.

But if it ran OK when parked, I doubt it developed a vacuum leak in the interim. More likely to be junk in your carb somewhere. It doesn't necessarily need a "rebuild" with all new parts but it'll likely need to come apart for a good cleaning.

Re: 67 is running rough and will not idle
 

Not sure if this will work for you, but I took the fuel inlet line off the carb, and used a spray bomb of carb cleaner to put as much as I could into the float bowl of the carb. The idea was to try to clean out the jets in the carb. I guess it worked, as mine starts and idles well. Gets terrible mileage though. Maybe the power valve is stuck open.

Re: 67 is running rough and will not idle
 

Ok try this if it runs fine just won't idle. Pull the mixture screws out and blow carb cleaner and compressed air through the mixture screw holes. Sounds like your idle jets are clogged. Do this a few times then put the screws in turn them out to 2 turns each and start the truck. Then tune the screws and it should idle.

Re: 67 is running rough and will not idle
 

Dave, Longbox, and BigRig: I will try all those suggestions this weekend. I sure would like to skip the rebuild :)

Re: 67 is running rough and will not idle
 

I'm not familiar with the Edelbrock carbs but on Quadrajets what is usually needed, in my opinion about every 2-3 years....is to fully remove them off the engine (about 15-20 minutes).
Then take them into a clean bench area with a container and thoroughly clean/spray them through with Carb cleaner.
I will often, carefully!!!....remove the top air horn in order to access the internals and clean that will carb cleaner to. If extreme care is taken the gaskets can be reused....if not, a gasket kit is about $20.
Then I used compressed every which where but loose on them to blow debris etc. out.
This always makes a big difference and is a positive maintenance event in lieu of opting for a rebuild...that may not be required.
again...not sure on the edelbrocks...but never, ever underestimate removing the carb and thoroughly cleaning it with carb cleaner and compressed air.
my two bits.
Coley:chevy:

Re: 67 is running rough and will not idle
 

Going thru the same thing also. Will take out the air screws and blow out to see if idle returns smooth.