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93 blazer lacking power


93blueblazer
10-31-2007, 04:10 PM
i have a problem with my 93 blazer 4.3 vortec (engine code w) 4x4. it runs a little rough at idle but when it warms up, it has absolutely no power, i cant even put it in overdrive. i do have 31 inch tires but im sure that doesnt do too much. it also bucks at driving speed, it is getting about 13 mpg. i havent smelled any gas yet from the exhaust. when it is cold it has alot more power, i can actually spin the tires, when its hot i cant do a break stand even on gravel. here's what ive done to it so far. CHANGED- spark plugs + wires, distributor cap + rotor, air filter , fuel filter, changed the egr, map + mat sensors, throttle position sensor, and i hollowed out the catalic converter. after changing all this did not help. ive looked online and seen alot of 4.3's with cpi problems, but most all of them had that smell of gas which i dont, that confuses me. and when i changed the plugs they all looked good. that was confusing considering it goes through soo much gas. i dont know what else to look for, i will check the timing in the next couple of days but im sure it wont be out . when it is bucking at driving speed it seems to be going from 5 cylinders to 4 ( i say 5 because when it is warm it lacks power). i checked the codes ( i have a cheap canadian tire reader) thats why i changed the sensors, those codes were on the ecm. now there are no codes and it is running terrible. and my engine light hardly comes on. if someone has any idea on what it could be i would be very happy. thank you

Chris Stewart
10-31-2007, 11:02 PM
Check your fuel pressure, you need to see around 55psi.

http://i131.photobucket.com/albums/p288/Clunk_/Image033.jpg

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