Sr20det hits wall after about 3000 rpms.... MAF maybe?

[devlmaycry]

Ok I got a 95 240sx with a s13 redtop. When I got the car it ran fine then over the last month it started acting up (minus the rectified squeak in the rear). It's mostly stock minus the aem truboost, turboxs BOV atmospheric, and walboro 255 (if I remember right). When I first noticed the loss of power I suspected boost leak or plugs so I replaced the cheap hose clamps with t-bolts on the hotpipe and tightened all the other ones. Replaced the plugs and gapped them to .028. I ran great for about 3days...

Then I noticed it loosing power again. Especially on the highway when I would go to pass It felt like it was pulling all the timing and wanted to back fire, but rarely would. No power at all. Under full throttle it doesn't want to pull past 5000 rpms, you can feel it wanting to back fire and has no power. However, under 3/4 throttle with no boost it wil cruise right on up to redline and behave well.... At least "well" considering. If I'm on the hightway in 5th and downshift to 4th (about 4k) it will do the same thing, but only once the boost hits.

So, I retightened all the clamps. That didn't seem to help at all, but now anytime I get into any boost under full throttle it has zero power. Though it seems like when I let it down to less than 3/4 throttle I get more power out of it. Vacuum seems fine and runs from 16-22. The boost will drop a lb or 2 when it looses power, but I'm not sure if the loss of power ='s loss of boost or the other way around. Seems like everyday it loses a little more will to live... Argh. Oh, and I just preplaced the fuel filter no change.

The car idles fine and drives fine under low throttle, but dogs down terribly any boost with more than 1/2 throttle. All the fluids look fine. Oils good, coolant it fine. Etc.

I'm just not real sure what it could be. I've read a alot of stuff saying maf, cas, tps, coolant temp, spark blowout, bad coil pak, or boost leak; pretty much anything and everything. I'm just trying to get a better idea of the most likely culperit before I spend all day trouble shooting things that aren't likely to be the problem.

Sorry for the long post just wanted to give as much info about the situation as possible. So, anyone whose dealt with similar problems or with more knowledge than me in the sr20det field feel free to throw me a bone please.
Modified by devlmaycry at 3:49 AM 4/28/2009