- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Black smoke is usually a sign you are using too much gas or it is flooding itself. your choke may need setting as well check your air cleaner. If it's dirty that will cause it to flood as well.
How long since a tune-up? If your computer controlled, are there any applicable trouble codes?
With the vehicle in park or neutral not much load on the engine. There is a load when you put it in gear. Does the engine have decent compression? Is it running rich or lean? Could be other issues?
Sounds like a fuel problem. If it is throttle body injection, check fuel pressure-should be around 15-20psi, I think, but you might check the specs for that. If it is carbureted, pull off the line at the carb and check flow and volume. It should spurt out and reach about a pint in a minute. The pressure on carbureted engines is low, about 5-7psi. The mechanical pump on carbureted engines is on the engine block. Maybe the arm for the pump is worn, or diaphragm has a small hole?
Probably you have a lean fuel mixture for cold start up and running, but performs normal when the engine has reached operating temperature. So check all items responsible for fuel mixture such as fuel pressure and flow, air leaks ( use a smoke machine for this) choke system ( if carburetted) , engine coolant temp sensor.
By "throttle body carb" I am assuming you to mean that the engine is equipped with Throttle Body Injection (TBI). The O2 sensors on that engine do not even start working for about 5 minutes. They are not going to cause a problem on start-up. A fuel filter will most likely not cause a problem on start-up or idle either. A fuel filter is most likely to cause problems on acceleration or when pulling a hill. A more likely cause would be a n Engine Coolant Temperature (ECT) sensor. If one of these is reading too low, it will cause the engine to flood and smoke black out the exhaust - especially on start-up. (LIke a choke sticking on an old carbureted engine.) If your truck is equipped with a gauge, there may be 2 Coolant sensors. One for the gauge and one for the computer. If you replace it, make sure you are replacing the sensor for the computer.
SCAN IT CHECK COOLANT SENSOR IT WILL CAUSES STARTING PROBLEMS IF ITS NOT WORKING.DOING COOL ENGINE START UP COOLING SENSOR MONITOR COOLANT TEMPERATURE SENSOR.IT WILL ENRICHEN FUEL MIXTURE JUST FOR COLD STARTING ENGINE.IT WORK LIKE SAME PRINCIPAL LIKE A CHOKE ON CARBURETER ENGINE.WHEN ENGINE WARMS UP THE COOLANT SENSOR AND OXYGEN SENSOR WILL LEAN OUT FUEL SYSTEM .WHICH IS CLOSED LOOP.CHOKE ON CARBURETER WILL OPEN AUTOMATICALLY AS THE THERMOSTATIC METAL COIL WARMS UP.YOU NEED A RICH FUEL MIXTURE WHEN COLD STARTING ENGINE.NOW A CLOGGED AIR FILTER BAD PLUGS + WIRES CAUSE WEAK SPARK NO START UP.SO I WOULD HAVE A GARAGE OR SOME BODY WITH A SCANNER SCAN IT TO SEE WHAT THE PROBLEM IS.YOU WONT SPEND TOO MUCH MONEY GUESSING.
MOST TIME A REBUILT IS HARD TO START.YOU HAVE PRIME THEM SQUIRT OIL IN ENGINE REMOVE THE SPARK PLUGS TO BUILD UP COMPRESSION.AND PRIME THE CARBURETER OR TBI ..BUT IF YOU ARE GETTING FUEL AND SPARK.PROBLEM IS YOUR TIMING IS OFF.
If the engine is turning over then it is either the fuel or ignition fault.When yoy tried to start after 20 minute,you must have flooded the fuel system(carbureter). Once excess fuel had evaporated the truck started.
You try putting fuel cleaner in tank or carbureter and see if it cures it.
×