Running Rich - What Should I Look For In Carb? Specific Symptoms

[natertot]

Hey, got an '85 2.8L with the Motorcraft 2150 carb. Hesitates when accelerating from stop, sometimes stalling. When warm, no issues but probably still running rich. Fails emissions on carbon monoxide only (very high levels). Really does not want to turn over when starting and when it does it sometimes puffs smoke.

Electric choke takes 3.5min to open from cold, seems reasonable. I replaced that accelerator pump gasket on the front of the carb also. I've set the mix screws to maximize RPM at idle, and I set the fast idle speed according to the manual. I put in a new O2 sensor and fixed a bunch of exhaust leaks recently as well. PO had replaced the mechanical fuel pump with an electric one.

Bought a carb rebuild kit, do these symptoms match anything that I should pay special attention to? Accelerator pump? Float level?

 

[tw205]

Ensure your electric fuel pump isnt providing too much pressure. Only need 4 to 8 lbs.
Set the base timing. 10° to 12°, then get a vacuum guage and set the idle mix screws to achieve the highest vacuum. Use the idle set screw to get the correct RPM. Then let us know how its running.
Puffing a little blue smoke at start up is OK if it has a lot of miles. Worn valve stem seal will do that.
If your gonna rebuild it, after disassembly, soak it in carb solvent over night. Then use air to blow out every passage part piece nook and cranny. Initial setting for the idle mixture is two turns out from bottom.

 

[natertot]

Ensure your electric fuel pump isnt providing too much pressure. Only need 4 to 8 lbs.
Set the base timing. 10° to 12°, then get a vacuum guage and set the idle mix screws to achieve the highest vacuum. Use the idle set screw to get the correct RPM. Then let us know how its running.
Puffing a little blue smoke at start up is OK if it has a lot of miles. Worn valve stem seal will do that.
If your gonna rebuild it, after disassembly, soak it in carb solvent over night. Then use air to blow out every passage part piece nook and cranny. Initial setting for the idle mixture is two turns out from bottom.

Hey this is awesome info! I assume I need some kind of gauge to measure fuel pressure? Or can I tell from the float bowl? For the idle mix, I maximized RPM which should in theory maximize vacuum as well right? I did set idle speed to spec after doing that.

As far as the smoke, yeah that sounds about right, 140k on it, engine rebuilt once already also. Good to know it’s not a time bomb ha.

For engine timing, I have the gun but I probably gotta pop off a timing cover or something and figure out where to point it so I’ll see if Chilton has that information. Manual says 10* for timing. Thank you very much for this though, I’ll feel a bit less lost diving into it tomorrow!

 

[alwaysFlOoReD]

Buy yourself a fuel pressure and vacuum gauge. Iirc at that low fuel pressure they will be combined into one unit.
There will be a pointer attached somewhere on the front of the engine close to the harmonic balancer, and there are lines of degree on the balancer. Clean the marks and use something white in the 10° groove. A paint pen works.