Enzo1089

iTrader: (13)

UPDATE: So I went an got a Snap on Compression tester from my buddy and the car tested at 155/170/170/190. So all the numbers are now above the minimal, but the first is still low and now that last one is high.

I added Oil to the first one and it jumped up to 175psi

So I need to redo the ring on #1 correct? And what's up with the last one

DONT BUY O'REILLY COMPRESSION TESTERS BY THE WAY!

buchnerj

iTrader: (19)

A few things to remember about doing a compression test. Make sure the motor is hot. Not just start it up and let it warm a little. Drive it around and get it up to normal operating temps. Then just disconnect the cam angle sensor and test each cylinder one at a time.

If the oil trick brought up the compression in that cylinder than yes there is an issue with the rings. Go buy a boroscope from NAPA or some other auto parts store, I found one for cheap <$100 and it worked nicely. Take a look and see how the piston top looks. Do you see any pitting or signs of wear on the cylinder walls? Most likely the ring is bad. If you are going to replace the rings in one you might as well make sure all the other cylinders are kosher too. Don't want to have to rip it up twice.

GG06MR

iTrader: (9)

Yes, you almost certainly need to redo the rings in it, and like buchnerj said, you might as well do a full bottom end rebuild while you have the head off. No point in just honing and throwing new rings into one cylinder. Are your numbers right to left or vice versa by the way?

Enzo1089

iTrader: (13)

my compression numbers are from passenger side to driver side. So whats up with the random high piston at the end.

GG06MR

iTrader: (9)

Good question. Mostly from my experience with Honda I4's, the cylinder closest to the throttle body usually takes the most abuse, since it is almost always the leanest running cylinder. For that reason alone, I would have expected it to have the low number instead of the high number on your engine. Did you disconnect the crankshaft position sensor?

Enzo1089

iTrader: (13)

Yes I disconnected it, Battery was fully charged, throttle body was completely open, and motor was just driving around town for a good 30 minutes.

Dmego4

19% is the max acceptable variation during a compression test... cams will drop the compression aswell.

project_skyline

iTrader: (30)

I wouldn't mess with it at this point. Your still within the cylinder variance. Taking apart the motor would be stupid, the compression overall is still pretty good.

Wht03evo8

I took the car to a local shop EQ tuning, and i told them about all the news about the Evo and we decided to do another compression test and a leak down test! The motor was solid nothing wrong..

But a question that is still bothering me is when i got my tune done just last Thursday at a local shop he had to stop tuning cuz of a 7 counts of knock at 5500 rpm! I just recently had them install new head studs, FIC 1050cc injectors, new Iridium plugs, Clutch, Flywheel and the Tune. What could cause the car to throw 7 counts of knock at 5500 rpm

GG06MR

iTrader: (9)

Great news on the compression and leak down testing! As far as the 7 counts of knock, it would be easier if we knew your mod list, but I'm guessing you either have an upgraded turbo and/or you're running high boost to need 1050cc injectors. I'm not an ECU tuner, but the obvious questions to me are....1) boost level? 2) Fuel type and octane rating? 3) A/F ratio? 4) have you upgraded your fuel pump as well? 4) spark plug type and gap?

rgeier11

I knew your engine was fine. Stop worrying. When it blows up, it's bad.

Wht03evo8

Sorry, for the late response!
8 turbo
10.5 TH
hallman MBC
upper and lower intercooler piping
Intake
264/272 cam
cam gears
TBE w/ Hi flow cat
O2 housing
porting exhaust mani
1050cc
255 fuel pump
intercooler


The spark plugs are BRAND NEW as in not even 20 mins prior to the tune iridium BC8-EXI (I think thats the model), the boost is set to 23psi and tapers to 19psi. Chevron 91 octane I NEVER run any thing less then that. A/F ratio is unknown i hate to say i have the map but i am unable to open it on my computer it is a .HEX file. if you know how to open it please send me an email at eac32286@yahoo.com and so that i can open it to be posted..

Raptord

iTrader: (10)

You need ecuflash to open the .hex file.

EvolNinja

iTrader: (22)

Hope you get it to work

Wht03evo8

Ok, i finally got ecuflash working on my Mac, so which numbers do i need to be looking at i am a Complete NEWB when it comes to tuning a car and being able to read these numbers. So anything you want to know i will tell ya. Air Fuel looks like it was 14.7