Misfire at high boost?

[Fuzz_Duster]

So my car runs ok besides a shitty idle, and starting a little sluggish, but once my guage hits any psi over 5, my car starts bucking and bogging down.
The vacuum is all over the place too at idle. Sometimes it will be 12 in/hg, and other times it will be 20 in/hg?? wtf?

Here's the catch though : It's only intermittent.

Like yesterday, hopped in the car, drove down the road, boosted 16 psi consistant with no flaws. Stopped at a stop light, took off, car hit 7psi, started bucking. So it will run fine for like 5 minutes then misfire the rest of the day.
It also won't start cold. It takes up to 7 tries of holding it in ignition mode while pumping the gas until it will turn over. Even warm it has a hard start.

CEL code: (everytime) P1128- Bank 1/S1- Lean


Things I've done about this problem so far:
New coils
New plugs (gapped correct)
Pressure tested
New pre-cat O2
Checked all vacuum lines thoroughly
Checked all Check vales


The only minor problem I have found is I have one fuel injector that has a cracked head.


any help is appreciated guys. I just wanna drive my car without worries for once!!

[njm23]

well, the fact that you have a messed up fuel injector, are running lean and misfiring should kinda tell you something. i suggest replacing that injector and seeing what happens before you do anything else.

[MultiAudis]

yeah why replace all that other stuff prior to addressing your KNOWN issue? At any rate, change the injector and see what happens, and if that doesn't do it, my guess is maybe a MAF going bad as you have already changed everything else.

[whoace]

Pumping the accelerator while starting does nothing. When you push the accelerator pedal, it cuts off fuel to the injectors. You want to prime pulse it. Turn ignition to on position, wait, then start.

Was the O2 a brand new Bosch? I would recheck the O2.

Other things to check

-Coolant Temp Sensor
-DV
-Boost pressure test (I don't know if that's what you meant. A simple physical check will not show all boost leaks; only obvious ones)
-Check exhaust for back pressure

I would check anything that would keep your car running in open loop.