I have a '78 F150 2wd with a L6 300-1v
I've recently replaced lots of gaskets, even the oil pan gasket
adjusted the carb, and idle
still getting dark smoke

ANY SUGGESTIONS FOR TROUBLE SHOOTING?

I bought this truck for my son last year and have been working hard to get it to run before his 16th B-day, one payday at a time...

 

'78 F150 L6 300-1v

 

Have you tuned it up? Plugs, wires, cap and button? It may have points in it too. It's been a long time since I worked on a gas motor. Timing adjusted? If it's putting out some black smoke, it's running rich.

 

x2^ plus vacuum leak check.

 

X3 I'd also add a new set of plug wires. Better parts store brand at least. Getting the ignition and timing right is a starting point. If dark (black?) smoke persists it is likely a carb issue. Rebuild or reman time. I had good luck with an "Autoline" rebuild from Autozone on my dent.

 

Holy crap... i thought California was draconian with regards to emissions testing.. thank goodness '75 and older vehicles are exempted. Thank you SEMA!!!

From: Air Care Colorado :: Exemptions

The following Colorado motor vehicles are exempt from emissions testing:

Newly-manufactured vehicles, for the first 4 model years, or until a change of ownership (click here for requirements regarding vehicles being brought into the program area from another state or from another part of Colorado);
Pre -1976 collector-plated vehicles
Pre-1943 horseless carriage-plated vehicles
Vehicles with a two-stroke engine manufactured prior to 1980
Motorcycles
Farm-plated vehicles
Electric powered vehicles
** Hybrid electric vehicles, such as the Toyota Prius and Honda Insight do not currently require emissions inspections.
** Homemade "kit" cars are exempt from emissions testing per Colorado HB06-1176.

Pre-'82 gray market, customs, and hot rods are subject to emissions testing per..

"Vehicles in this category may include reconstructed, rebuilt or street rod cars. For further information, contact your county motor vehicle registration office, or the Emissions Program Office at the Colorado Division of Motor Vehicles at 303-205-5603. Most of these vehicles are tested with the idle test rather than the I/M 240 test.

In general, these vehicles that have Colorado-assigned identification numbers in lieu of a Vehicle Identification Number (VIN), and all such vehicles must be evaluated at an emissions technical center operated by the Colorado Department of Public Health and Environment. Paperwork from this evaluation must be presented to the emissions testing center in order to obtain an emissions test. Save this evaluation paperwork as it must be presented at all future emissions tests on the vehicle"

 

Move to a different state. :-)

 

No points and condenser unless the dizzy's been swapped. DuraSpark electronic ignition introduced in 1974, but not all vehicles came with it until 1976.

HIO: At one time CA smog tested all 1950 and newer vehicles. Not only did they have to have PCV installed, but the crappy NOX device that was spliced into the upper radiator hose.

 

Yeah, I am old enough to know that... suffered for a little bit with my 65 Mustang... Some stations even wanted an enclosed air cleaner. Specs were all over the map depending on the tech working at the time.

 

In colo. it depnds on the county .. Because the truck is a 78 f150 it probably came with an egr .. Check to make sure the valve is functional and the plate is cleaned out .. Make sure the vacuum line is properly routed and connected .. Pics of the motor without the air cleaner on the carb would help ..

 

Black smoke means its too rich. Check to make sure the choke is opening all the way there Is also a diaphragm gasket in the carb that can tear and cause black smoke. If those are ok I would check the float level.

 

The NOX device was written into legislation by the govenor, Jerry Brown, yes the same guy we have now, the best part was he had a financial interest in the company that made the device, he made a fortune off that.
Sorry to hijack, my old smog buddy has told that story for years.

Like the posts above me state, black smoke is too much fuel, is the choke not opening all the way, or float level too high, how does it run? does it act like it's getting a lot of fuel?
Whats the condition of the fuel? I have seen a gallon or two of diesel in a tank of gasoline cause black smoke and it did not run that bad, I doubt that is the case though.

 

EGR valves introduced in 1973.

The factory installed EGR/Carb spacer plates were aluminum, heat caused them to burn out internally.

The FoMoCo "service part replacement" plates were cast iron.

 

I love saskatchewan! No emissions! But what do you expect for a province of 1.2 million people? Lol

 

Warmer temperatures! Snow and ice are for play, not for daily living IMO.

This is the 21st century.... I have a hard time understanding why folks choose to live in a place where the temperatures can kill ya. Maybe we Americans should send you guys luggage and bus tickets. LOL.