Chevrolet Repair: 95 chevy blazer acceleration/rotor distributor cap, chevy blazer, heater blower

Question
1995 Chevy Blazer,
4.3 vortec

Lately, on acceleration is reluctant, as if refusing to gear up noticibly from second and third gears.  When on highway, had great trouble going into fourth (automatic transmission).  At first, this happened on exceptionally cold days (-5 Celsius and colder) and appeared to be absent at freezing temperature or warmer.

When the problem occurred, my girlfriend claimed letting off the gas for a second, then applying gas stopped the resistence and would gear up, droping rpm, I had not noticed this to work myself and do not believe rpm had increased when trying to accelerate.   Either way it first appeared a cold-related problem, or at very least the cold added to the problem.

Recently, the problem became more pronounced, however the weather has stayed very cold, and my Blazer died 2 blocks from leaving my house.  The distributor cap rotor had loosened, I replaced the part assuming it was damaged. Everything worked fine, so I thought the problem was solved.  Within a week the whole acceleration problem returned, so had the cold weather.  The next day, weather was warmer, yet acceleration still getting worse.  It is a problem from first to third and does not want to go passed 50 km/h without forcing and coaxing.  Examining the old part showed no damage and the new part is not loose.  My girlfriend said the trick with the gas pedal is no longer effective either.  Filters are new and the truck starts no problem.
Other issues (if related) seem typical of chevy blazer's shortcomings include: heater blower only works on a blue moon unless tapping the blower from under the hood does start it, 4 by 4 cant engage (yet engages in the summer when airconditioner is on! with trouble to disengage), and the check engine light has been on since purchasing the vehicle used 3 years ago.   The truck feels as if it will break down again, thinking the rotor/distributor cap was an isolated/unconnected problem.  I have done all repairs myself and would like to continue to do so, but I need help figuring out what the heck is wrong.  Thanks

Answer
Hi,

 I think you are correct assuming the cap and rotor were a new problem.  If you have no way to check fuel pressure one thing you can do without diagnostic equipment ot narrow down the symptom you are describing to me is take the upstream 02 sensor out and drive it.  If you have a vacuum gauge you can put it on the motor and drive it.  It kind of sounds like your exhaust is plugged.  I would really like some input as to what your fuel pressure is when it is bogging out though.  It needs to be 55-60 depending on engine load.

wayne