Well I'm planning on going FI with my 4th gen, so to start it off I ran a compression test to see how the engine's health was to start. The shop manual says the nominal level is 178lbs, but when I ran the test (engine warm) it came out
190/190/200/190 now I know it's holding all it's pressure which is great, but the variations say to only allow +/- 28lbs, which is still well within the limits, but is there a problem if your compression reading is too high?

I know this is kinda a newb post, but I haven't had any technical training on motors. I know a little about the basic workings, but I'm learning about the harder stuff as I go

 

Carbon deposits in the combustion chamber will raise compression.

 

There's two ways that work to clean this, one Distilled water on one of the vacum sources at 2500 RPM (if you want to do it ask and i will tell you how) and/or letting ATF oil in the pistons over night.

 

yes please explain

 

i would use distilled water instead of normal tap water: https://honda-tech.com/zerothread?id=207473
(i heard once that make sure that your rpms just drop 200RPM and that keep that rate if you are doing it through a vacuum hose)

Ok, i found an alternative too:
Ok, I'm gonna let you guys in on a little secret. You go down to the GM dealership and ask the guy at the parts counter for some TOP ENGINE CLEANER not "top end cleaner" start your car up and pour some directly into the throttle body til the car dies. Then start it back up. Be warned this **** is like a smoke bomb so don't do it in your garage or even on a residential street. do this maybe 2 or 3 times. I'm serious about this! The guy at the smog shop told me this after I failed the CA smog test. I still didn't pass but the #'s dropped dramatically. It flushes out the carbon build up in your motor.

By SOHC'd up

AND the ATF way:
Take off all your spark plugs, rotate the engine 90 degrees after TDC (Can't remember if it was 90 degrees, but what you are trying to do is make all your pistons even in the same position, somebody correct me if i'm wrong) and pour ATF on the spark plugs holes and fill. Let it sit over night. Next day get a syringe (spel?) and try to get all you can get out. Turn on the car, let it warm up a bit and drive it around at high RPMs, a lot of smoke will come out the exhaust, so don't worry. After doing this i would recommend an oil change, in case the ATF went through the rings (nothing to worry). do another compression test, remember at WOT, warm and take the injectors fuse out.


[Modified by GZERO, 5:16 PM 2/12/2003]

 

awesome! thanks for the info. There's probably a lot of carbon in there if it raised the compression by 12lbs per cylinder. I've never really had the engine overhauled so I think it's about time.