background - bought a 03 trailblazer 400 a couple weeks ago. from what I can tell, has a k&n and custom pipe. No idea what if anything else has been done to it.
heres my issues. first off the thing pulls hard in the mid and top range. no break up, no sputtering, rips around as long as its revved up.
1. idle sounds maybe a tad low. when sitting at idle and giving it full throttle it doesnt really bog, it sounds like its sucking in too much air or something. makes a deep hollow sound for about a second then revs up.
2. in reverse and in forward gear, it has to rev up before it moves. I dont have a tach but im guessing it doesnt move until about 2k rpm, maybe higher. I can "brake boost" it, hold the brake and rev til i feel the gear kick in, then go. When i do that, it almost feels like turbo lag, it moves until it hits the pipe, then hang on.
3. Yesterday i was able to find a long straight stretch of trail, and I went wide open. It pulls hard with no break up, but at what im guessing was 40mph, i felt another surge of power.
Im not sure what any of this means but the only real issue I have is having to rev to move. if you guys have any insight or suggestions that would be awesome.