3SGE Stutters and Backfires at 2500 RPM, swap almost done, PLEASE HELP!!! Options

[KAOS]

Ok the engine went back in and starts up with no issues whatsoever.

Idles like a champ.

At 2500 RPM it starts sputtering and backfiring like crazy. We can't figure it out, need your help.

3RD GEN 3SGE

Full rebuild, new rings, seals all around, timing belt, water pump, etc etc etc.

Timing is perfect. Leak down test revealed ~95%+ across all chambers, so thats good.

Fuel filter was clogged up, so we replaced that. I have a 6 AN fuel line that was built because of the JDM fuel rail. Fuel pump is working at normal capacity (90L/hr). Gas used is 91 octane. Has plenty of spark.

Any ideas? Questions? I really need your help on this...

It's almost as thought the car is in limp mode - or has a rev limiter installed (it doesn't).

I will post a video soon with an example.

This post has been edited by KAOS: Jul 23, 2014 - 8:21 PM

[mi645]

brake booster can cause a vac leak causing the engine to run rich thinking its lean, check all ur vacum stuff, 3sge especially 3d gen really relies on vacuum more than anything. doesnt have a maf just map.