Hey guys I am new to this site. Ive tried doing a few searches and haven't come up with anything solid. I'm seeing if anyone out there might have a similar issue. My evo 8 was running great until a few weeks ago. I installed a new FMIC and buschur double pupmper. Had the car tuned and was doing fine for a few days. I then changed a v-band on the turbo and re-sealed a fuel line fitting as I was getting a small drip at the connection at the top assembly. After that, I am able to drive smooth up until about 4krpm and I get a bad sputter in any gear. Doesn't happen under WOT , only partial throttle.

My mods are fully built 2.1 stroker, FICs 2150, buschur double pumper and fuel rail, Fuel lab FPR, spoolin up COP, PTE 6262, STM 3.8 FMIC, stock ecu. New NGK br8es gapped 0.018.

Things I have done recently to try and fix the problem: New plugs, New COP kit, New CAM sensor, had tuner check fuel and timing at 4 k rpm- fine.

My plans this week are to check my injectors to see if something got in them when we changed the fuel pumps and to do an E-85 test. Maybe bad gas.

Any input would be highly regarded. Thank You.

 

Wow, 2 weeks and no one has any suggestions.

 

Do you have evo scan or some sort of logger?
What are tps readings? Sounds possible to have a dead spot in the tps. Sure sounds like a tps fault.

What does afr do

 

Sounds like compressor surge.
Hard springs in the recirc valve can cause that.