1985 s-10 blazer: power loss

i recently have had power loss (almost like my engine has a frog in its throat). when i start out in 1st gear (manual transmission, v6) the suv is 'doggy' and acts like it is in a higher gear. i get this in every gear as i start out and it gets better as i apply more to the gas pedal but it never gets back to running 100% power. it acts like it is going to quit if i dont rev it up and pop the clutch. what is strange is on saturday i had the oil changed at a jiffy lube and it ran perfect for two days and is now back to acting up. i changed the pvc valve as recommend at jiffy but as i was leaving with the old one still in place it ran great and also after i replaced it with a new one. but today back to normal (abnormal). a friend suggested rebuilding the carb and another to check the plugs. it was tuned up 2 years ago. it has 144,000 miles and has ran well up to this point.

What is the engine vacuum reading at idle and at 2K RPM?
Any check engine lights on?
Check for codes and post back any code no?
How is the base timing?

i have not had a code meter hooked to it. how much does that cost? I have not rpm meter in the dash. unsure of base timing. and no engine light is on.

It could be as simple as the carb's choke is not opening fully, especially on colder days.
Take the air cleaner lid off when the engine is cold. You will see the choke blade on the top of the carb will be closed. You can open it all the way with your finger.

Now, drive the truck until its fully warmed up. Take the air cleaner lid off and varify that the choke blade is open all the way. If not, look for the source of trouble.

Your truck will have an electric choke. There might be a dirty terminal for the electric choke wire or the choke heater itself no longer works.

Also, the choke linkage may be physically dirty and is binding.

i have not had a code meter hooked to it. how much does that cost? I have not rpm meter in the dash. unsure of base timing. and no engine light is on.


Auto zone and some parts places give a free code check.

Vacuum gauge is a cheap and basic tool. Get the reading.
The readings will tell you a lot about engine running and timing
On vacuum gauge check engine vacuum at idle and speeded up about 1/2 way.
Post back readings.

Have base timing checked.

And as said check that choke good.