Help needed! Running lean??

[Sweetdaddyglasses]

Just bought a 2005 legacy gt and am currently trying to diagnose a issue and was hoping you all might be able to help point me in the right direction.

Now posting this i have already read all 30 some pages of the large misfire thread that is on here.

 

Now my question: taking the misfire and compression issue out of the equation (explained below), cylinder #1 #3 #4 running lean what are some of the things that could cause that? Also possible fixes?

 

-Rebuilt short block at 1800 miles

-Rebuilt block with all sti parts (crankshaft, rods, pistons, rings etc) and king bearings I believe

-valves where set in within proper tolerances, and seated correctly

-Before i bought it had been driven 100 miles and plugs pulled all 4 looked really good and compression numbers where also good.

 

The bad: had a misfire in #2 and #4 (But cylinder #4 stared first) As well as really rough idle. We pulled plugs after ~1600 miles and #1 #3 and #4 all where running lean but cylinder #2 had a perfect looking plug so we replaced all four of them and swapped a coil on it but no luck. Next we did a compression test and #2 had no compression. No oil residue on plugs so i know the shortblock is safe. Timing was also checked last week and was perfect. Only experience misfire between 0-2000 rpms between 3k to 4k it runs perfectly. We know its burnt valves now.

 

The background : now it has had both O2 sensors replaced as they are very new looking in a otherwise dirty engine bay. have a new MAF on the way as the A/F ratio isn't doing what it's supposed to while monitoring it on my access port. it looks as thou before the block went originally at 139k they where trying to track down the same issue of misfires, As a lot of the trouble shooting was already done due to new parts. i don't feel as if 3 of my 4 injectors are done for.

I have not thrown any more codes to help narrow down the search, but i have thrown a few all lettered codes ( sorry don't remember them, i do recall P then a combo of E and F in the code). After getting the access port I put on a stage 1 map and it helped run a little better but still experiencing erratic A/F ratios at idle and pushing in the clutch to come to a complete stop(most of the time it hangs at 16 or 17 when it shouldn't be). But we don't wanna open up the heads and replace all the valves until we get the lean issue figured out.

 

Any help you could possibly give me would be greatly appreciated

[CloudSeed777]

Zip-tie all the hoses coming off the inlet if you haven't already.

[Sweetdaddyglasses]

i haven't looked at the turbo inlet, next time i see my mechanic i will pull out the inlet to inspect it, are they notoriously weak or something in factory trim?

If it had a issue on the inlet would it be super noticeable?

Well looks like i have some reading to do, thank you for advice.

Okay newb question, but why zip tie them? Do they pop off or just suck in excess air?