Chevrolet Repair: 1991 s10 problem, pvc valve, vacuum leak

Question
i have a 1991 s10 pickup and it has always idled a little high but cut down alot when i put on a new pvc valve well just last week it started to spit and spudder and backfire and when it does that it loses all power no matter how far you hit the gas. it does it when you put it in two high of a gear or when your just regularly driving it im thinking it might be the catalytic converter or a burned valve but aint sure can you please help

Answer
Hi William,

I am not the orginal expert you contacted.  I found this question in the question trash can.  Once it ends up there, any of us experts can answer it.  I hope this helps.

A burned valve will cause havoc but should be there even at idle.  A catalytic converter is the same as plugged exhaust.  Idle ok, but with a vacuum guage, the vacuum falls off upon acceleration until the motor stalls.  

A vacuum guage should rule in or out both of your theories.  Good guess, try the guage and see.  If not those things, do you have any codes?  I guess you would have told me that if you did so I am guessing NO.  That means it is not computer related.  

It could be dirty or clogged air cleaner, bad MAP sensor, vacuum leak.  But I would think you would have other complaints.  

I am taking a long shot here and I say:  I SUSPECT FUEL FILTER.  That would come on suddenly, and cause all the symptoms you complain of.  

Hope this helps.  

C J S