Ok...here's the story. I have a '92 S10 Blazer 4.3L Vortec that I've had for about two weeks. It had a miss-fire when I got it...and it needed a general tune up anyway. So far I've replaced the air filter, spark plugs, wires, cap & rotor, PCV, and cleaned the MAP (or MAF, not sure. sensor just before the throttle body in the air intake). Now it runs really rough, when I accelerate it sounds more like a diesel truck than a gas one. And as I accelerate I have very little power (my 4 cylinder ford tempo have more get up and go). Any ideas...??? Someone told me the computer may have compensated for all the old equipment that was on it, and now that it has new stuff on it, its not resetting itself?? At any rate, I can drive it, I just don't have the get up and go that it used to have.

 

The engine you have in your blazerhas a CPI fule injector , they commonly go bad.I just replaced mine in my blazer, but if you said it was running good, And you cleand your sensors an did a tune up you could make sure you didnt cross spark splug wires and disconect and reconect the battery to reset the computer hope this helps

 

All the spark plug wires are in the right places, I made sure that they weren't crossed. I was told the cleaner I used (I don't remember the name) on the MAF sensor may have damaged it. The friend I borrowed it from his MAF sensor on his toyota suv is also now bad (it is a mass airflow cleaner). We also tried timing it, and my spark is all over the place, I couldn't adjust it. And a side note...my muffler rusted through today, so when I drive...I sound like a dying sherman tank rolling down the road. I'm starting to wonder if I bought a big lemon! I'll try resetting it by disconnecting the battery and then reconnecting it. I'll repost sometime tomorrow.