Vacuum Elimination and Computer Issues
Fleet Mechanic
Joined: Jul 2011
Posts: 1,916
Likes: 4
Is your choke stove hooked up?
Is the choke rod bent?
FTE Legend
Joined: Jul 2010
Posts: 32,875
Likes: 48
From: Northeast, OK
If the choke doesn't open you probably don't have it connected properly. As was said, it should be connected to the stator connection on the alternator. Check for about 7 volts at the choke when the engine is running.
As for the engine racing, it is on the fast idle cam since the choke hasn't come off. Fix the choke and I think you'll fix that problem as well.
As for the engine racing, it is on the fast idle cam since the choke hasn't come off. Fix the choke and I think you'll fix that problem as well.
FTE Legend
Joined: Jul 2010
Posts: 32,875
Likes: 48
From: Northeast, OK
Yes. Take the wire from the alternator off at the choke and put your DVM's red lead on the connector you took the wire off of and the black lead on ground. With the meter set in low ohms mode you should see several ohms resistance. If not either the heating element is bad or the ground wire is off the choke.
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 40
From: EXTREME southwest CT
Gary, 4180's don't have a ground wire, just a single bullet-like connector.
They ground through the carburetor itself.
MOFORD,
If it is racing and the choke is closed either the choke cap is incorrectly adjusted, the fast idle cam is sticking, or you have a vacuum leak.
-Has it ever been tinkered with? ... Are there screws holding it in place, or are there three conical anti-tamper nubs securing the stamped steel 'collar' holding the choke element in place?
There are hash marks on the periphery of the bakelite housing.
I don't know what the calibration code calls for on an F-150 with Cat's. (mine is two lines tight)
There should be a small aluminum tag affixed under one of the screws of the vacuum diaphragm cover with a Motorcraft number stamped on it. This can be decoded.
Also, there is a Holley build number stamped into the front of the choke horn.
Holley has all the jetting and adjustment numbers on pgs. 15-16 of a pdf on their website.
If your choke element is burned out (open circuit between the carb body and the choke wire terminal) I'm pretty sure I have a spare.
If your EGR plate gasket is burned through beneath the spacer it will rev high on choke. Try spraying a little carb cleaner around the base and see if the engine runs different. Felpro sells the gasket for around $10.
They ground through the carburetor itself.
MOFORD,
If it is racing and the choke is closed either the choke cap is incorrectly adjusted, the fast idle cam is sticking, or you have a vacuum leak.
-Has it ever been tinkered with? ... Are there screws holding it in place, or are there three conical anti-tamper nubs securing the stamped steel 'collar' holding the choke element in place?
There are hash marks on the periphery of the bakelite housing.
I don't know what the calibration code calls for on an F-150 with Cat's. (mine is two lines tight)
There should be a small aluminum tag affixed under one of the screws of the vacuum diaphragm cover with a Motorcraft number stamped on it. This can be decoded.
Also, there is a Holley build number stamped into the front of the choke horn.
Holley has all the jetting and adjustment numbers on pgs. 15-16 of a pdf on their website.
If your choke element is burned out (open circuit between the carb body and the choke wire terminal) I'm pretty sure I have a spare.
If your EGR plate gasket is burned through beneath the spacer it will rev high on choke. Try spraying a little carb cleaner around the base and see if the engine runs different. Felpro sells the gasket for around $10.
FTE Legend
Joined: Jul 2010
Posts: 32,875
Likes: 48
From: Northeast, OK
Jim - I forgot we are talking about a 4180, and even had I remembered I wouldn't have remembered that there is no ground wire. 
Glad you caught that as it makes a huge difference on fixing the problem if it is burned out due to the screws, as you mentioned.
Glad you caught that as it makes a huge difference on fixing the problem if it is burned out due to the screws, as you mentioned.
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 40
From: EXTREME southwest CT
Gary,
I wish I had a 'before' photo of my old carb.
There were no digital cameras back then.
IIRC, that Hot Rod article reprinted on FLEMWORLD shows the anti tamper screws and how to cut a slot in them with a Dremel tool so you can remove them to adjust or replace the choke element.
They are 8-32 I think.
I wish I had a 'before' photo of my old carb.
There were no digital cameras back then.
IIRC, that Hot Rod article reprinted on FLEMWORLD shows the anti tamper screws and how to cut a slot in them with a Dremel tool so you can remove them to adjust or replace the choke element.
They are 8-32 I think.
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FTE Legend
Joined: Jul 2010
Posts: 32,875
Likes: 48
From: Northeast, OK
Gary,
I wish I had a 'before' photo of my old carb.
There were no digital cameras back then.
IIRC, that Hot Rod article reprinted on FLEMWORLD shows the anti tamper screws and how to cut a slot in them with a Dremel tool so you can remove them to adjust or replace the choke element.
They are 8-32 I think.
I wish I had a 'before' photo of my old carb.
There were no digital cameras back then.
IIRC, that Hot Rod article reprinted on FLEMWORLD shows the anti tamper screws and how to cut a slot in them with a Dremel tool so you can remove them to adjust or replace the choke element.
They are 8-32 I think.
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