Ok, so I went ahead and did the smog removal on my `82 F-250, along with doing a full tune up. This is my original thread for reference

https://www.ford-trucks.com/forums/1...l#post14387899

But now I have a problem. The truck barely idles and it runs completely pig rich. Tune up (plugs/wires/cap/rotor) was all good parts, not the cheap stuff. Plug gap at .044 per specs. One thing I noticed removeing the old plugs was that they were all black as death with soot, but no oil, not wet at all. Removed all the smog as well as most of it was disconnected or broken anyway. Now all the ports are plugged with big port from the T going to the booster, PCV line going to large port on carb and vac advance going to the ported vacuum port on the carb. I've checked, double checked and triple checked for vacuum leaks and can't find any. The booster is brand new as well, so that's not leaking either. The EGR is still in place, but not connected. I did test it though and if you open it at idle the truck stalls. If you open it around 2000rpm, the truck runs really rough like it has a dead miss. So I'm assuming the EGR is sealing properly.

When I bought the truck last month, it ran decent, but not great. Seemed a little down on power, but it had vacuum leaks all over (bad booster, broken vac lines, etc). Now that I have eliminated all the vacuum leaks, it runs pig rich. And when I say pig rich, I'm talking BLACK puffs of smoke out the exhaust at idle and what sounds like a bit of a miss. But snapping the throttle oddly enough revs it very quickly and smoothly (probably the snappiest throttle response I've even seen on one of these engines) and the smoke changes to grey. The exhaust will choke you. But let it try to idle and it runs kinda rough. To idle at all I had to crank the idle set screw all the way in till it stopped and it still only idles around 500-600rpm. It idled around 1000-1200 before because of all the vacuum leaks. Give it a little gas and hold it there (around 2000 I'd say) and it will smooth out a little, but still nasty exhaust and a little bit of a random miss it sounds like. But like I said, snap the throttle and she revs fast and smooth. I haven't drive it yet because I still have to bleed the brakes from when I replaced the booster and master last week.

So this is where I'm a little stumped. The carb is from a later feedback equipped engine with the feedback equipment removed. Not sure exactly what it came off of though as it was already on it when I got it. Looks like a factory feedback YFA, but it says "manufactured by Weber" on it. I tried adjusting the mixture screw and nothing. It was 2 turns out, I reset it to 1.5 out and no change. I even cranked it all the way in till it stopped and no change. Still idles the same and revs the same. This has me REALLY confused. I've never really been great with carbs, but I know this is a huge problem. I need to get a vacuum gauge and hook it up, but won't be able to do that till probably Sunday or Monday. I'm thinking this carb is just totally FUBAR and should buy a new one. Is there another adjustment I am missing here? Any other thoughts?

 

Pick up a kit and rebuild your carb. Needle and seat are probably toast and leaking. You had so many vacuum leaks before, it didn't matter how rich the carb was running all that air leaking in was making up for it. ~Bill

 

Sounds like you have the same problem another guy on here had recently. Take the aircleaner off and get the engine idling. Take a flashlight and shine down the carb throat and see if you have fuel dripping into the carb. You should see no liquid fuel going into the engine. If you see any liquid fuel, your float level is too high in the carb bowl, and it's spilling over into the engine.

If you find that's the case, look for a dirty fuel filter and dirt stuck under the float needle, a float with gas in it, or a float that is not adjusted correctly.

 

Another issue that can cause this type of pig-rich condition, is the accel pump inside the carb. If it has a pin hole in it, fuel leaks thru into the vacuum port under it. If the truck sat for a while, and has been pressed back into service, the "rubber" could have cracked.

 

I was following that other thread, but wasn't sure if the issue was related as he seemed to have all kinds of other problems too. Once it stops raining here I'm gonna do a little more looking, check the timing, check manifold, etc. If everything seems ok, i think I'm just gonna order a new carburetor. The fact that this one is not original, and I'm not ever sure what it is originally off of, plus the tag is missing, finding the correct kit for it is gonna be a pain. And then I don't even know if the carb is set up right or not in the first place. Guess I'll check a few more things first and go from there

 

Ok, messed around with it again today. Checked the timing, it's good. Was off by a couple degrees, but nothing that would cause this problem. I reset it to 6* though, no change. I did notice that the truck idled and ran much better on a cold start. Once it started warming though, right back to what it was. Checked for vac leaks again, found none. Even hosed the manifold this time with carb cleaner and it didn't flinch. It appears to have a newer exhaust manifold on it though as well as a new gasket, so the intake should be sealed up tight. Looked down the carb while running and it is dribbling a little fuel from the squirter, but not much. Seems to be about a drop every second or so. So I think that's because I have the idle adjustment cranked all the way in to keep it running. Definitely not enough fuel to make it run THAT rich. So at this point, I have to think there is a problem INSIDE the carburetor, such as a leaking accelerator pump as mentioned by Rogue Wulff. I was able to ID the carb though via the number stamped on the side of the body (tag missing) which is 7652S. Shows as being an `85 only 300 feedback carb. So at least it is the right size carburetor so getting a rebuild kit should be easier now. So what do you guys think, does it seem to be an internal carb pronlem here?

 

Here is a short vid i took to show you how rich it is really running. The truck is idling around 500 rpm cranked all the way up. Throttle response is great, but you can see from the exhaust it's getting WAY too much fuel.

 

If your carb is a unit designed for the feedback system, it is never going to work 100% correctly on that earlier model without the full feedback system. You may get it to work ok, but it will leave plenty of potential unused. I don't think those feedback carbs have the proper port for hooking up the vacuum advance.
You might be better off sourcing a reman or used unit for an earlier model truck, and going from there.

 

I was told the feedback didn't matter because it doesn't actually control anything on the carb itself. TPS is gone now, all the other crap too. Only difference I see is the solenoid that attaches to the side of the bowl, but I was under the assumption that it was just a bowl vent solenoid. And it does have a ported vacuum for the advance

 

That solenoid adjusts the fuel mixture. That's the point of the whole "feedback" thing.

 

Did some more research on this carb and found that you are right, it is a mixture solenoid. BUT, it is not capable of making it rich enough to do what my truck is doing. The range of control is pretty narrow, more for emissions control that anything. Alot of guys seem to be running it disconnected and it only runs "a little rich", and as you can see by my video, I'm a long way past "a little rich". I'm thinkin I should just buy a new carb anyway, but I'm tired of dumping money and time into this thing. I should have just fixed my other truck and been done with it (needs new motor)

 

There's one kit that fits pretty much all of the YF/YFA carbs and they generally run in the $20 range so from where I'm sitting seems you should just pony up and redo your carb. I'd be willing to bet once you get the top of it off you're going to find something pretty obvious that's causing your issue. ~Bill

 

There is actually several different kits which was my first dilemma, but I now know which one I need. And it was never an issue of "ponying up", it was a issue of making sure I was fixing the right thing. "Dartboard diagnostics" is not the right way to do things. I've seen people spend thousands chasing a simple problem by just replacing parts. I wanted to make sure what I had was right or wrong before dumping more money into it. Seeings as it is almost definitely the carb that is the issue, plus it's not the correct one, I think I'm just going to buy a new or reman carb (the correct one for the truck).

 

The correct one for the truck probably isn't going to be much better in light of having stripped out the smog stuff. But hey, give it a shot ~Bill

 

Care to explain?