Loping Idle, Stalls

[2GeeEssEcks]

I've searched around quite a bit, and can't find what I am looking for. I'll start with listing what I did to my car during my engine rebuild:

Walbro 255
AFPR
HX40 turbo
External wastegate
New headgasket, timing belt, balance shaft delete
Front mount intercooler
EGR blocked off, complete emissions delete
Fiav bypass (coolant blockoff) on throttle body

Ever since I started the car again I have had issues. Most have been worked out and were because of the fuel pump. That seems to be working well now. Currently the problem is on start, RPMs jump up, and then car wants to stall. It will surge then fall unless I hit the accelerator. Car idled fine for awhile last week when it was on jacks, but I took it off the stands and drove it and it died repeatedly on the street until I limped it back and it won't even idle now. It revs fine into the high RPM range and sounds very healthy, but then just idles up and down until it stalls out. It is running rich as well.

What I have replaced/verified:

Engine timing is spot on, tensioned perfectly and the marks line up
Getting a constant 41 psi fuel pressure at my regulator
o2 sensor cycling properly
Coolant temp sensor functioning correctly
MAF functioning correctly
Swapped in an alternate IAC motor
Throttle body was rebuilt as well, adjusted TPS with the guide on vfaq
ECU was inspected, no problems
Spark plugs replaced
Substituted multiple sets of injectors, that does not seem to be the problem
Tested resistance on spark plug wires, within specs
Have not boost leak tested since I don't have a compressor at my house, but I took great care rebuilding and I do not suspect leaks from anywhere, but it is possible although pretty unlikely because everything is new and tightened down/inspected

Really frustrated with this, hopefully one of the knowledgeable people on here can help.

 

[Canadian_CD9A]

Try hooking up an IACV, see what happens.

 

[2GeeEssEcks]

You mean putting in a different IAC motor? I actually had a spare and swapped them, no effect. Forgot to add that to the list of things I have tried, I'll update.

 

[Canadian_CD9A]

You say you have your FIAV blocked off - I assume that's Fast Idle Air Valve?
The ECU is supposed to compensate for it - it would explain running rich, not idling, etc. The IACV/FIAV's purpose is to idle the car.

 

[2GeeEssEcks]

Sorry, using bad terminology. My car definitely has an IAC, it has the FIAV bypass, not the blocking plate. The only thing that is blocked off is the coolant. I was told the only effect of bypassing it would be extra cranking on cold starts.

 

[DSMBanditFZ6]

Irregardless of weither or not you know there shouldn't be a boost leak. It's always good to check. It will also show any wore out gaskets on your intake side.

BLT.

 

[2GeeEssEcks]

Okay, going to attempt to boost leak test today with a bike pump.

 

[2GeeEssEcks]

My car is leaning out with the brake pedal depressed. Was there a check valve built into the 2g brake booster hose by chance? I replaced the hose and there is something wrong with the car leaning JUST because of the brake being pressed.

 

[poteau]

Sounds like could be a vacuum leak/ boost leak test. The engine is suffering under load which could mean a leak down test might be in order. Or at least a compression.