Failed HC Emissions for the 2nd time
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
1100 HC's? Sheesh... sounds like the carb is pouring gas down the intake 
Sounds like the power valve, rebuilding the carb is the right way to go - could even be a leaky float needle, which should be in the kit.
Make sure the choke is opening all the way?
Does (or did) the engine burn oil? If so, it's all in the exhaust, and will show up as HC's...
Sounds like the power valve, rebuilding the carb is the right way to go - could even be a leaky float needle, which should be in the kit.
Make sure the choke is opening all the way?
Does (or did) the engine burn oil? If so, it's all in the exhaust, and will show up as HC's...
Freshman User
Joined: Feb 2002
Posts: 48
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From: Texas
The float...I wouldn't worry about it...they can go bad, but I've rebuilt a many of these and have yet to find a bad float. To test it, once you get it apart, put it close to your ear and shake it. No noise is good. If you here what sounds like tiny beads rolling around, that's OK too. If you hear a sloshing noise, that means there's liquid in the float, read gasoline, and it will have to be replaced.
This is all assuming it's the original brass float and hasn't been replaced with a black solid plastic aftermarket piece.
Bird
This is all assuming it's the original brass float and hasn't been replaced with a black solid plastic aftermarket piece.
Bird
Junior User
Joined: May 2004
Posts: 61
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Just try setting your idle way up. When I first moved to AZ and went through emissions for the first time with my 79 I failed at idle but passed under load. So I went home and tuned it up, adjusted the air screws on the carb and then set the idle very low thinking that if the engine wasn't turning very fast it couldn't be creating as much emissions. So I had it tested again and failed very badly at idle but still passed under load. After talkiing to some guys at work they said turn the idle way up and any car will pass at idle no matter how bad it is running. So every year now I set the idle all of the way up in the parking lot of the test station, pass the test and then set the idle back down in the parking lot again. Works every time. The only other way that I've been able to get it to pass with the idle set to the recommended setting per the sticker on the hood is to retard the timing a lot. But then the engine has little power you can hardly drive it. By setting up the idle I can still pass even with a very advanced ignition timing.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
You can't turn the idle up too far, the testing machine will cough...
I've been thinking about this, and two things come to mind: idling way rich (and the obvious fixes) or so-so ignition. Dwell, points, coil, wires, plugs, cap, anything that is making the spark weak at idle.
I've had my FE390 in my '74 highboy passed by the "right guy" who played with things to get it to pass. If you're in one of those states that do not allow "regular" mechanics to inspect vehicles, I feel sorry for you
PS: the things he played with were idle screws, idle speed and even creating a vacuum leak. He got me down from 700PPM HC to less than 300PPM. The limit was upper 400's... And, no cats. Now, it's more than 25 years old, so it's excempt (if it wasn't in the local crusher already, that is).
I've been thinking about this, and two things come to mind: idling way rich (and the obvious fixes) or so-so ignition. Dwell, points, coil, wires, plugs, cap, anything that is making the spark weak at idle.
I've had my FE390 in my '74 highboy passed by the "right guy" who played with things to get it to pass. If you're in one of those states that do not allow "regular" mechanics to inspect vehicles, I feel sorry for you
PS: the things he played with were idle screws, idle speed and even creating a vacuum leak. He got me down from 700PPM HC to less than 300PPM. The limit was upper 400's... And, no cats. Now, it's more than 25 years old, so it's excempt (if it wasn't in the local crusher already, that is).
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Freshman User
Joined: May 2003
Posts: 47
Likes: 0
From: Delaware
Well here it is and seems like a year later and still the truck is not tagged. I rebuilt the carb with a kit and including a float. You guys were right it wasn't that hard at all.
BUT...what is hard (actually just about impossible) is finding the TSP & Dashpot Assy. (the part that contains the curb idle adjusting screw). The electrical part on the rear of mine is cracked and bad. The spring is bad on the pump diaphragm "cover". Not the inside spring that comes in the kit. It is the outside spring that puts tension on the lever.
I went to PepBoys, Napa, local parts and the Ford truck dealership...they all tell me the parts are obsolote.
That is the update to this post. My question now is where can I get the parts mentioned above?
Thanks for all the great replies they are very informative.
MaxTek
BUT...what is hard (actually just about impossible) is finding the TSP & Dashpot Assy. (the part that contains the curb idle adjusting screw). The electrical part on the rear of mine is cracked and bad. The spring is bad on the pump diaphragm "cover". Not the inside spring that comes in the kit. It is the outside spring that puts tension on the lever.
I went to PepBoys, Napa, local parts and the Ford truck dealership...they all tell me the parts are obsolote.
That is the update to this post. My question now is where can I get the parts mentioned above?
Thanks for all the great replies they are very informative.
MaxTek
Postmaster
Joined: Feb 2003
Posts: 4,043
Likes: 4
Try contacting Pony Carburetors. They restore old carbs for Fords. They may sell you the parts you need.
http://www.ponycarburetors.com/default.asp?page=about
http://www.ponycarburetors.com/default.asp?page=about
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Freshman User
Joined: May 2003
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From: Delaware
I searched the website and they don't sell the part. So I emailed them with the specifics and no answer yet. I guess that's another strike.
Most of the replacement carbs I see don't even have this part. Is it needed? Can I take it off? The instruction sheet that came in my rebuilt kit has two exploded views, one with an altitude compensator and one with out. The one without does not have this dashpot assy.
Most of the replacement carbs I see don't even have this part. Is it needed? Can I take it off? The instruction sheet that came in my rebuilt kit has two exploded views, one with an altitude compensator and one with out. The one without does not have this dashpot assy.
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