Issue has been resolved, thanks forum.


THIS IS THE CULPRIT, THIS WAS ONE BACKWASH OF INJ 3


Heres what I know:
I purchased this car from someone I know that let it sit for about a year due to his purchase of a C6 and a HellCat, he assumed it had a bad tank of gas and the rare stutter was just the gas not completely ran through. It drove fine with a very rare stutter around 80 and I drove it for about 500 miles, then let it sit for about a month (its not my dd) then rapidly got worse to this point in about 75 miles.

At idle or low rpms it sounds like a Subaru. I drove it to O'reillys to scan the code and getting up to speed or keeping it about 3k ish would clear it up. I intended on getting meth and a dyno tune but obviously thats on hold. I'd like to get this sorted before I tow it over Kozmic, save me some $$ on labor.

Mods: Been on car for past 30k miles
GSC S2, valves, and springs | Ported head and exh mani | DW65C | FIC900cc | FP Red
AMS IC and Turbo back. Tuned by Kozmic.

Heres what I've done:
Visually inspected wires and plug, nothing of concern.
Brand new NGK #1422 (factory) gapped at .021 (old set looked dirty, nothing of note)
Only ran Exxon or Shell 93 since ownership.
One bottle of seafoam.
Compression test: 95 on every cylinder using harbor freight tester (this is what I have, its done me well, new orings). Tested warm, right after drive. 5 Cranks. Same numbers as when first purchased.
Ohm tested wires and coil pack.
Cleaned injectors. SOLVED ISSUE

 

That compression is very very low.

Swap injectors over.

You should do a cylinder leak down test and see were its leaking. I.e valves.rings. head gasket.

 

If it goes away with load chances are the rings are bad and the load is creating a seal.

 

I assumed it was lower than expected however with mods and such I read it can fluctuate, granted it is on the low side. I read as long as they are even then its kosher'ish. That being said, all 4 cylinders are on point with only #3 misfiring. I will swap injectors around however and build myself a leak down tester when I can.

 

95 psi is about half a normal n/a engine and 55 or so low for a low compression turbo engine. But if theyre all equal youd think you can rule out low compression or youd have a p0301,2 3 4

 

It is below the minimum:

Evo 10:
Standard: 158psi
Minimum: 109psi

Did you test it warm? Are you at altitude? Do you have another tester to try?

 

Photos of plugs?

 

Cyl 1, 2, 3. 4th looks similar. Amazon decided to send a plug a day late.

 

Note: I did spray them down with carb cleaner to check them before my new plugs got here. This was after 20 miles or so, same look as before I sprayed them down.

 

I started to clean my injectors. I didn't test spray pattern first on inj 3 as I back washed it first. I blew some gunk out of the bowl and I still have a lot! (I think). Spray is kosher now.

 

It's a bit hard to tell from the photos but the threads of the plugs look a bit oily.


Maybe in a week or so, pull out the new plugs and see how they look.

That's if you're still driving it.


I'll take a guess that it's rebuild time.

 

Close, delete, or do what you need to do mods. Issue has been resolved.

 

Was the issue dirty injectors?

edit: Nevermind, I see you edited the OP.

 

Just curious, how did you clean the injectors?

 

I didn't exactly "clean" so much as flush. I jimmy rigged a switch to a mower battery to pulse the injectors that I pressurized with a can of carb cleaner, rubber hose, and a large syringe. I first back flushed, then forward and check spray pattern.