With these 2 codes indicating both banks lean tells you that you have false air entering the engine either in the form of a vacuum leak or a bad air flow sensor or map sensor. But in any case it is un-metered air. Not too many possibilities on this one.Most of the time a vacuum leak.,
This truck is the map sensor type system, as far as testing for vacuum leaks you can run the engine and use carb cleaner and spray around the intake manifold and listen for the rpm`s to increase some and at that point is the area the leak is in. It can be in the form of an intake gasket to a deteriorated vacuum hose. But in any case that is why you are getting lean faults on both banks.
You do not have a carburator, I think the map sensor is what are refering to. Here is a picture of it. Were you not able to find a vacuum leak? Make sure you check all the vacuum hoses good.
That is great you found a loose line.The reason I say this is because like I said before in order for you to have lean codes on both banks there has to be a common denominator,(vacuum leak or false air intake). I understand now what you meant about the carburator.If at a later date you end up with this type of fault where both banks are setting lean codes always start with vacuum leaks because 95% of the time that is what it turns out to be. I have a 94 s10 blazer with the 4.3 vortec so I have an owners point of view on this one. I am glad things worked out.
I have been paid a long time ago I will try to close this question myself. don`t know why it is still open.
You are going to have more than one problem 1 is what caused the overheating and 2 is the engine. If the coolant level is full in the engine then the overheat may have been the thermostat sticking. The bad part of all this is that the engine quit on its own while diving. This is what I would do. Do a compression test and see if there is good compression. Check for spark at the plugs, if both of these check out then check for fuel pressure. If the compression is low then the overheat damaged the engine. You can also do a wet test on the rings by putting a few drops of oil into each cylinder and see if the compression changes allot, if it does then the rings are damaged.
Ok, The antifreeze could have boiled over and blown out past the pressure cap. It is designed to release after 15psi. The intake gaskets could have let some out. They are known for leaking at the front and rear of the intake manifold to head seal.
As for the shutdown, I don't know that these engine have a shut down system in place.
The fuel pump test port is on the steel fuel line at the back left of the intake manifold.
The p0101 is usually a dirty MAF sensor or vacuum leak.
My bet is the intake gaskets. Start the engine with the cap off, and fill the system. While it is running, add as needed. This way you can see if there is lots of bubbles and bleed the air out.
It is a 3-4 hour job to replace the intake gaskets.
I think the test port is the same valve as R12, so that may be an option.
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