carb adjustment

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Apr 22, 2016 | 09:32 AM

lnm

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carb adjustment

I have a 1973 F100 Ranger XLT. The problem I am having at this time is that on cold startup it runs at an extremely high RPM's. I realize that setting the automatic choke will cause engine to run faster but mine is way to fast. The other problem is that I can not seem to kick it down even after it runs for a period of time. Once the engine comes up to temp it idles fine. Where can I make an adjustment to keep cold RPM's down? I believe we are dealing with a 390 V8. If more information is needed I certainly will get it in order to work on this problem.

Thank You
lnm

Apr 22, 2016 | 09:40 AM

CelticOne

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Joined: Sep 2014

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From: Bathurst, New Brunswick

Hi lnm. Welcome to FTE!

Stock 2v Motorcraft 2100/2150? 4v? When was it last rebuilt?

Apr 22, 2016 | 09:49 AM

lnm

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Quote:

Originally Posted by CelticOne

Hi lnm. Welcome to FTE!

Stock 2v Motorcraft 2100/2150? 4v? When was it last rebuilt?

As far as I know it has never been rebuilt.

Apr 22, 2016 | 10:29 AM

beartracks

Lead Driver

Joined: Nov 2000

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From: Albuquerque

Actually sounds like a possible vacuum leak.

Apr 22, 2016 | 10:38 AM

Tedster9

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From: Waterloo, Iowa

Quote:

Originally Posted by lnm

As far as I know it has never been rebuilt.

Put a kit in it, your truck will run ten times better. With today's gas some people recommend every two years.

Apr 22, 2016 | 03:23 PM

JD Q

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Joined: Feb 2016

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With the information I see and understand, the motor warms up and maintains an idle. That is if the idle is around the curb idle (idle in gear). The curb idle should be posted in the engine compartment. If the idle is correct, when warm, there may not be a vacuum leak.
It could be only the choke fast idle adjustment. watch this video:

you may be able to ask a narrower question so someone can help.
hope it helps.

Apr 23, 2016 | 09:52 AM

lnm

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Quote:

Originally Posted by JD Q

Thank you for the video. It is a good starting point and hopefully will help my problem. Couple more questions if I may ask. How many vacuum tubes actually come into the carb and does the entire vacuum system of the vehicle affect the carbs operation?

Thank You

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Apr 23, 2016 | 11:37 AM

lnm

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Quote:

Originally Posted by Tedster9

Thanks again. Moving on to another issue I have. The alternator light is coming on intermittently. Went for about a 10 mile drive and was not on. The next time I started in was on and would not go off. Finally went off after a couple more starts. Has come back on again. Have had the alternator tested and it tested good(only three years old). Took cover off regulator and points come together so seems to be working. Have cleaned connections between battery and regulator/alternator. Assuming a possible broken or bad connection somewhere. Help if possible. Thanks