Sputering at 5k
 

Just got my new 1g, and after driving it for 15 mins, it sputtered under boost at around 4k. Thought it was overheating, as there was no intake going to the turbo, just a screen over the inlet. Got an intake today, but it is still doing it, seems a little better but not much. Car runs great when cold, no problems. Water temp is around 205 after driving for a while. Any ideas? Here is my engine setup:

Balanced Crankshaft
ARP Main Studs
Eagle H-Beam Rods
Weisco 8.5 to 1 compression heat coated pistons
New High Volume Oil Pump
All new timing components. (pulleys, tensioner, etc.)
Unorthodox Underdrive Lightweight one piece Racing Pulley
Resurfaced block
Bored over and honed cylinder walls
Balance Shafts removed
1mm Oversized Stainless Steel Valves
Bronze Valve Guides
Lightly Ported and Polished
Web 546/547 Street Grind Cams
Power Enterprise Kevlar Timing Belt
ARP Head Studs
Cosmetic Multi Layer metal Head Gasket
3" Stainless Steel Turbo Back Megan Racing Exhaust
2.5" Victory Performance Stainless Steel O2 Housing
Tial 40mm Waste Gate
Supra TT Fuel Pump
Re-wire fuel pump relay
8an braided fuel feed line from tank to fuel rail
K&N billet 8an fuel filter
SX Adjustable Fuel Pressure Regulator
780cc Fuel Clinic Fuel Injectors
MAF Translator 3" GM MAFS
Bullseye T04B 50 Trim turbo (oil & water cooled, -10an oil drain)
Aluminum High Performance sheet metal Intake Manifold
2.5" Aluminum Intercooler piping
Tial 50mm BOV
2nd Gen Polished Throttle Body Elbow
32" x 8" x 3.5" Front Mount Intercooler
Alumium Mishimoto Radiator Slim Fans (One Puller & One Pusher)
New Water Pump
New Hoses Braided
6an turbo coolant feed and return line
New Battery
New Alternator
New Coil Packs
New Ignition Module
New Spark Plug Wires and Plugs(BPR7ES)
EPROM ECU with Keydiver Chip reprogrammed for the following; 8000 Rev Limiter NO Airflow CAP No Fuelcut Octane Reset Shift CE Light @ 7000 RPM Enhanced closed loop MAPS Knocksum Gauge 780cc injectors/264us deadtime 3” GM MAFT 850 RPM Idle 45 PSI AFPR 11.0:1 WOT A/F FED/AWD Locked Baro & Airtemp

Sorry the list is long, but i just want to make sure i dont miss anything that might help diagnose the problem. Thanks for the help.

Re: Sputering at 5k
 

Could be a boost leak or just needs to be tuned.

Re: Sputering at 5k
 

Car has been tuned. Wouldnt boost leak happen even if the car was cold?

Re: Sputering at 5k
 

Sorry, I missed the cold part.

Anything weird in the logs cold versus hot? Like in the hz, airflow, timing, wideband o2s? Is the MAFT mounted in the engine bay? Did you try a different ECU? Grounds?

Re: Sputering at 5k
 

I will hook up the palm and check the logs today. The MAFT is mounted in the glovebox, and all the grounds apear to be fine. I have not tried using another computer, dont have one available.

Re: Sputering at 5k
 

Did some data loggging, it seems that when running good the O2-R reads .8V under boost, even after shifting, but when running bad the O2-R drops to .01V when under boost.

Re: Sputering at 5k
 

Also, under acceleration, coolant temp is around 210, and when coasting, coolant temp is around 217.

Re: Sputering at 5k
 

ideas, anyone?

Re: Sputering at 5k
 

I guess I would start from scratch and verify things like base timing. Replace and correctly gap the spark plugs. If the spark plug wires are old, I'd get some new ones.

Re: Sputering at 5k
 

I had mad sputtering when I would accelerate hard. I found my turbo was shredded....check your turbo out.

Re: Sputering at 5k
 

Turbo is fine, was just the t.p.s.