The actual numbers don't matter as much as the difference between the cylinders. I've heard that 10-15% is the max you want on the engine. It sounds like you have 3 cylinders down on compression which is kinda odd. A leakdown test is what you want to do next.

The subaru sound is what's getting me. One time I forgot to plug a coil back in and it sounded like a subaru...it was down one cylinder to cause this. Even though the motor didn't exactly pass a compression test I don't think that's your issue. A DEAD cylinder would casue this...not a few low cylinders. Any CEL's?

 

5000 ft aprox..

 

Just keeps giving me this damn p303 code , Remember I did blow off a Lash adjuster and rocker arm , I found all the pieces of metal , popped the new ones back in ... Still sound like that , almost like the number 3 injector is bad ?


how the hell do I swap injectors. where are they LOL this is my next step I think I am onto something here.


You see thats the only cylinder I am getting a misfire reading on ..


hmm

 

atm pressure at 5000 feet is approximately 17% lower than sea level. so the accepted 150-165 psi for an lnf would equate to 125-137 psi

 

i would redo your compression test with a charger on the battery, because the initial first crank will be quick making high pressure and the rest will not have as much juice in the batt so they wont spin as fast making the next one even and the first one high. do it with the fuel pump fuse out. if for some reason fuel is injected it can fill small leaks in the cylinder and give a false read. also i crank it with the gas pedal fully depressed until the cylinder compresses about 8-10 times to make sure the cylinder makes all the compression its going to make. some people will be like you only need 3 but from my experiences replacing gt2 turbo motors under warranty, this is the most reliable way that is acepted. it allows each cylinder the same chance to build full compression under exactly the same constant situation.

all the fuel injectors can be accessed by removing the intake manifold. the manifold curves over the top of the fuel rail and injector assembly and that is all encased in a chunk of foam to keep noise down. they are fairly easy to get to.

still though when my motor dropped a valve i smacked 3 cylinders as the rockers were spit out and like you number one was the one with the sealed cylinder haha

 

So that should be an acceptable range then for sure .

Looking at my logs I've been keeping it's been consistently P303 ....

Swapped Coil packs and plugs.

Compression looks good , Only thing I can think of is Injectors?

Running E85 I wouldn't be surprised running this lean would explain the injectors duty cycle limit over worked one of them because it had a valve not lifting correctly resulting in it going nuts ..

My theory for right now

 

Can you swap them between the rail ports or is it a one rail type of deal , Guess I'll know when I get the intake mani...

I sure do appreciate it guys , Hopefully I am on to something here..

 

im pretty sure u can swap them around on the rail. i have some extras for sale if u need one

 

Someone spoke of a seal tool in here makes me wonder

https://www.cobaltss.net/forums/2-0l...m-help-253925/

Got like an hour before Ricer Zone closes

 

Before you pull the injectors you will need another rail that comes with a one time seal. Also, i could be wrong but i think you need new teflon seals on the injectors if you pull them out

 

i think that tool just makes it easier. the shop that worked on my car removed them without it

edit: nvm they pulled the entire rail off and replaced with a new assembly

 

When you remove the injectors, you MUST replace the teflon seals and they have to be sized and installed on the tip with a GM tool. I have a used one.

Each injector seal kit is around $30 from CED and includes the o-ring and teflon seal. You will need 4 kits if you pull the injectors out of the head. One if you can get the rail off without pulling the good injectors out of the head, and reuse (not recommended at 2800 psi) the o-rings.

You will also need an intake mani gasket once you pull it to get to the fuel rail.

I have one good used injector and the seal tool I can sell for $75 shipped, but it won't go out until Tues evening if you paypal me tomorrow.
PM me if you think you need it and I'll send my paypal address Monday. Got to sleep now, 4 am comes early.

 

i know the rail is one time seal i took mine off as a whole assembly and left the injectors attached. i dont have any seal problems but if i do it again ill be resealing it.

 

The injector seal kit comes with the spring clip, teflon seal and o-ring for one injector. You don't need a new rail unless it leaks on a weld. 4 injectors need 4 seal kits if disturbed.

I have a good used rail also with sensors & wiring, just one good injector though. Sold the others.

 

If you removed the injectors from the head and reused the same seals, there is a problem. They will leak. You would have done better to leave them in the head and only removed the rail from the injectors.

 

is there a way to tell... because i dont have the foam insert aroud the injectors(stupid dog) and fuel does not spray or leak out of the injectors during operation.
i may just be that one lucky guy?

 

im 99% sure my injectors were removed and seals were reused... what are symptoms of a leak?

pretty much saying the exact thing as him ^

 

Doesn't look good if you ask me. Similar for me as well.
I had
146
126
135
30

#4 was toast but STILL couldn't see anything from the top but once out the ring land was busted to Hell.
#2 which held 126 had the ring land broken as well but it hadn't come out. It was floating between the rings.

 

what boost were u running? over 25 lbs is too much for these motors...

 

dont be so sure about that i have hero ran my factory turbo to 30psi and have the fuel tuned tuned for it on the street as well. that takes alot of time to finetune as far as pulls go. mine was happy as ever until i ejected a rocker with factory springs.

 

So just to swap 2 injectors on this car costs 60 dollars + the tool , And I don't even know if that is whats causing it..

What would be an alternative to swapping 2 injectors with each other to figure this out ?

Buy another rail

Great ,, this cars looking like a 2013 GT500 down payment already...

I mean if an injector is clogged or fried it can for sure cause a misfire right ?

I'll do a leak down test tomorrow but I'm seriously thinking it's an injector now since others have had a similar issues..


My cylinder pressure might seem low to some of you because of my elevation ..

 

But what explains the 15% - ish difference from 2,3,4 from #1?

 

Pull the fuel pump relay...

EDIT: nvm lol

 

When I had a leak around the teflon seal in the head, it would pop like popcorn as I got into boost. Never really smelled fuel, but compression was 140 ish while the others were 155-165.

When I pulled the rail to inspect, the #3 injector was stained black from fuel & carbon coming around the seal. Actually the seal was nowhere to be found on my #3 injector. No pieces, parts, nothing.

 

I have a box full of LNF engine parts, if you need something. CHEAP!