Thread: Need help to idle...

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OK..... fired it up. Cannot get it to idle without using the foot. It's a fast idle, but that can be adjusted by the screw under the choke housing. Just need some help to get it to idle by itself so I can work on timing and tuning. I was never good at initial set-up, that was Dad's area - I was the one with the foot on the gas pedal while he adjusted.

The deets - 1969 302 with a freshly rebuilt Autolite 4100. Stock choke, not manual or electric. Still running the stock distributor. Changed intake from Ford 4-bbl to a Weiand aluminum intake. Eliminated the heat tube from exhaust to choke and eliminated the PVC hose from valve cover to base plate as running breathers now.

Thanks in advance.....

David

Sounds like a vacuum leak - get a can of carb cleaner and with the engine running (a friend helps here), spray around the base of the carb and the area where the intake manifold meets the heads. Any change in speed indicates a vacuum leak.

Also - I think you may want to reconsider the PCV (Positive Crankcase Ventilation) setup. Unless your engine is real tight you'll be making a bit of a mess around where your breathers are located. The atmosphere inside the engine becomes more laden with oil vapor as the engine "ages" and tolerances grow. You need a breather to allow flow into the engine and the PCV then uses vacuum to literally suck that oil laden vapor into the intake stream where it's burned along with the fuel. If you don't use the PCV, make sure the inlet is well sealed

Good Luck,
Glenn

OK.... appears I have vacuum leaks between base plate and intake.

What carb gasket do y'all use to suck this up? Silicone OK here?

David

Originally Posted by Dsprint2000

OK.... appears I have vacuum leaks between base plate and intake.

What carb gasket do y'all use to suck this up? Silicone OK here?

David

I would use a straight edge and verify that the manifold isn't warped / twisted. You can use a thin film of silicone as long as it's not an oxygen sensing EFI system. Carb motor should be fine. Also - if it's a stock ford thermostatic type choke, you'll need that heat tube or replace it with an electricaly heated unit. Otherwise it'll take forever for the choke to open.

Not EFI. Yea, will check intake for warpage when I get the carb off. That would bite - it's a brand new intake....

Ugh...... on the heat tube, was afraid of that. Unfortunately the old one broke on the way out....another new piece....

David

Originally Posted by Dsprint2000

Not EFI. Yea, will check intake for warpage when I get the carb off. That would bite - it's a brand new intake....

Ugh...... on the heat tube, was afraid of that. Unfortunately the old one broke on the way out....another new piece....

David

If the intake is new, and you followed their instructions for installation and torque of fasteners. it's probably fine. did you use new gaskets when carb was installed?

Someone use to make a adapter that would fasten to a header or exhaust pipe. If the manifold piece is broken, you can usually drill out the old parts and sleeve in a new tube. Don't forget that this "style" is a "controlled leak" as it pulls filtered air down one tube then through the manifold where it heats the air and then up to the thermostatic spring which coils and uncoils with temperature. If it was mine, I'd go to the parts store and buy the electric conversion and wire it up. My point oh two!

Yup.... new gaskets always - never use the ones laying around for 10 years. LOL...

Tomorrow, I'll pull the carb and get new gaskets and re-install with some silicone for added protection.

Agreed on the choke - electric one on the shopping list for next payday....

If you get all external vacuum leaks fixed and still have problems, the motor could have a vacuum leak from the crankcase into the head ports from the underside of the port. It may be a little early to see it, but check the spark plugs for oily. That could be oil vapor from the crankcase. If this is the case, I have further instructions for you. Oh, and by the way, TRUST NOBODY. A lot of the parts we are buying these days are being machined offshore. I'm seeing more and more of posts on this and other forums from rodders that are saying so and so doesn't fit or so and so leaks.

This is a old carb correct , not familiar with Ford, but are you sure its not your throttle shafts? Could need rebushing.

This is a fresh rebuild I had done this year - never ran.

One question - I was reading some other stuff on another forum, am I supposed to be using a thicker gasket between the intake and base plate? I used the 'regular' paper one. I saw mention of using a 3/16 or 1/4" gasket there and then the usual paper between spacer and carb. Or, just stick to plan of using RTV?

Techinspector - I'll let you know when I get the carb re-installed. May not be till next week as gone this weekend.

OK.... last question this morning. Can I use the Holley electric choke kit w/o modification? Or do I need to go to Ford?

ps...... Thanks all for the help - it is greatly appreciated. I was pretty lost earlier this week. When vacuum was mentioned as the culprit, the light went on. I am so looking forward to driving this rig! Also spotted that full throttle was not being allowed as was misadjusted - HOMADE oughta scream now......

David