I put a 2005 trailblazer motor in my 2002 gmc envoy 4.2 now I keep blowing the flex line inside from the pump to the outlet what wrong

SOURCE: 2006 GMC Envoy and the A/C fan wont work in number 5 position

replace the resistor 4 the blower motor that should slove that hope this helps

SOURCE: Need firing order diagram for 2002 gmc envoy

one, five, three, six, two, four

The plastic intake should have this sequence molded into it somewhere, and even the corresponding cylinder numbers in front of their respective holes. Have fun, and thanks for posting on Fixya.com

SOURCE: 2002 gmc envoy shuts off when i turn on the ac whil ideling

If it does it when idling I would suspect an IAC motor (Idle Air Control). If it is opening too slowly the added air the motor needs will not be supplied fast enough and the engine will kill.

It could be other things also but this is where I would start.

SOURCE: My 2002 Gmc Envoy is stuck in 4wheel low. I

Try disconnecting the battery for a few minutes, that might get you out of trouble for now. There are some common problems with these 4wd systems. Most common is the mode position sensor on the encoder motor. Sometimes it can be the switch on the dash. Fact of the matter is I can't tell you what is wrong without using a scantool to retrieve the fault codes from the computer controlling the 4wd.

SOURCE: how to change water pump on 2002 gmc envoy

First, copy this diagram down so you will have a guide to putting your serpentine belt back on when you need to...



Follow this link to a "how to" video on replacing your vehicle's water pump. It will take awhile to watch the video(s), but will be well worth it.

http://www.wonderhowto.com/how-to-replace-water-pump-vehicle-102464/