93 blazer lacking power

[93blueblazer]

i have a problem with my 93 S-10 blazer. it has a 4.3 vortec (engine code w) here is the problem: when the engine warms up it has no power and it seems to go from 4 to 5 cylinders ( i know it has 6 cylinders but when it is hot , it has no power) i cant even put it in overdrive. i do have 31 inch tires but i dont think it should be that bad. so far i changed : spark plugs and wires, dist. cap and rotor, air and fuel filters, egr valve, mat and map sensors, throttle position sensor, the cat has been hollowed out. i changed those sensors because my cheap canadian tire diagnostic tool told me that those sensors were faulty. i went online and did a little research and found that these trucks were known for bad cpi units, however almost all of these could smell gas from the exhaust, i do not have any gas smell. and when i changed the spark plugs the old ones looked pretty good, none were fouled or wet. the truck also does really bad gas mileage. it idles a little rough , even cold. when cold it has alot more power, i can spin the tires, when hot, i cant even spin on gravel. i dont know what else to look for. if anyone could help me i would be verry happy. thank you .... i really want to fix this truck, it is a really nice truck. thanks again

[Chris Stewart]

Check your fuel pressure, you should see 55psi. Kits are available at most chain type auto parts stores. Harbor Freight had a sale on them too.

[93blueblazer]

thanks, ill check the fuel pressure within the next couple of days.

[old_master]

GM fuel pressure spec for CSFI & CMFI is 60 to 66psi, (cold engine, pump running, engine off). Pressure must remain above 55psi for 3 to 5 minutes after the pump shuts off.

1993 and earlier has TBI, spec is 9 to 13 psi.

[93blueblazer]

thank you guys for your help but i think i blew the engine in my truck today. i took it for a ride and it stalled on me so i started it up again, when i restarted it i revved it up a little and it started to knock a little and antifreeze was leaking from all over under the motor ( dont know where the antifreeze was leaking from because i have a skid plate under the truck). wow was a mad,, i guess now i know why the truck didnt run very good.

[93blueblazer]

i found a motor for my truck today, it is from a 92 astro van, it's a 4.3 and the engine code is a W, it should be the same i think, i stopped at the GM dealer and i was told it would fit, later i called a autowrecker and he said that it probably wouldnt fit. if the engine code is a W like my engine is and it has the same fuel injection system then why wouldnt it fit.. i think he just said that so that i would buy a motor from him.

[old_master]

Before going through the trouble and expense of replacing the engine, have it checked out first. It may be something less costly than an engine to repair/replace. Intake gaskets make a big mess when they leak, who knows, that might be all it needs.

[93blueblazer]

thanks alot for that idea but the other engine i found cost only $ 400 and im sure the guy i bought the truck from will pay for half. im doing all the work myself so there wont be any labour. i dont think that repairing my engine would be any cheaper, i am not sure where the knock is coming from, at idle it sounds ok, rev it up a little and it knocks. im thinking i had a bad gasket or something and it sucked too much air and burnt a piston. i dont know for sure, i cant see where the antifreeze is coming from, i should take the skid plate off and look iguess. i probably will bring the truck to a mecanic and get his diagnosis but i still think that a swap will be the best way. thanks again.

[93blueblazer]

i checked the anti freeze leak today and i think it is coming from the water pump. that is no big deal, there still is the knock however and it still runs like #$%& when it is warm. it doesnt sound like a piston, more like something in the head, but even if i would fix the head the truck would still run crappy , i think anyways. unless my problem is a burnt valve or something , then by rebuilding the head it would fix the problem. guess i will get that checked out.