RB20DET issues: Hard start and really boggy

[jmill145]

Having a problem with my RB20 swapped project hatch. I bought the car with the motor in it and it sat for a while before I got to it. Completely stock RB20 aside from a FMIC. Wiring specialties harness. Walbro 255.

The car refuses to start after it sits for a few days unless you give it some ether. It'll fire right up on ether and idle pretty well but it has absolutely no power. It barely makes it around the perfectly level parking lot at my shop and doesn't want to build any boost. The car will continue to start (without ether) but stops starting once it sits for a day or two. Symptoms are exactly the same with the MAF unplugged.

What I've done so far:

New plugs - good spark across all 6 coils
New MAF
New known good ECU
Boost/vacuum leak tested - all good
New fuel pump
No codes at the ECU
Fuel pressure is solid
Timing is good, pulled the front covers and everything is lined up at TDC.
Fresh gas
Compression tested - ~160 PSI across all 6

What's tripping me up is that it exhibits identical symptoms with the MAF plugged and unplugged. Am I correct in thinking that if this was some kind of sensor/ECU problem the car would at least be drivable in limp mode? It's not at all. Starting to think this is a fuel problem? I'm going to send my injectors out this week so that should hopefully eliminate that variable.

Can anyone shed some light on this? I have an FSM but it hasn't been much help so far.

[Yellow4g63]

If you know anyone close to you with another RB try the CAS.

[jmill145]

If you know anyone close to you with another RB try the CAS.

Tried another CAS, identical symptoms.

[Yellow4g63]

Try another coolant temp sensor. or Just unplug it and see if anything changes.