I need some help

[]{iwi]

ok heres the deal 90 civic si w/teg xsi b16 done the swap like 3 months ago no real problems with the swap, had to replace the dizzy (brearings started to go out) but all and all its been real good. ok so when i got it in and started i done a compression test it hit like 235 across and felt real good well like a week and half ago i swaped the M.C. and booster that came with the swap and i started to have some rough idle (a bit high and fluctuating) and i had just did the dizzy like 3 or 4 days befor so i thought it may have moved a bit. but i had changed the idle set screw befor so i tryed it and the idle seemed to smooth out, so ok its running fine and all seems well. so today i thought i would check it out a bit put the timeing light on it (dead on) and while i was at it i thought id check the compression,well here is where things go wrong hooked it up to #1 and hit the starter 120ish WTF so i do the rest of them and its hiting like 120ish across the board. ok so first thought head gasket well if the head gasket was blow it would more that likely be low on like 2 cylinder not all 4 but maybe. but heres the next prob. its not smokeing, its not useing any oil, its not loseing any water, and its still running like it was when i first got the swap done. it dont sputter it fires right up it does not dog around it fells really strong but the compression has droped like a 100psi all the way across. so i started checkin it out well maybe i could find something. first thought it has jumped time and bent the valves so i pull the valve cover and set it tdc, its dead on. well maybe the rings r going bad so i warm it back up and put a little oil in #1 and hit it up for the compression again no diff. i have no clue what it could be but im gonna do a leak down tomorrow but i really cant see any reason for the drop in the compression anyone have any ideas at all???

[91civicDXdude]

I can verify this. I was over at Kiwi shop last night checking out his car.. i cant explain it either.

HUGE loss of compression...

runs fine, doesnt smoke, doesnt use oil/water, doesnt miss, doesnt backfire, no noticeable loss of power (which would be expected in the case of such an extreme loss of compression).

get that leakdown done :P

I first thought it might be valve seats, but when it hits 120-140psi, it holds the pressure and doesnt leak out likeyou would figure if the valves werent closing.

hey kiwi remember when we checked your CRX Si and the valve was sticking on one cylinder and it was like 180-180-0-180 lol...

[]{iwi]

Originally Posted by 91civicDXdude

hey kiwi remember when we checked your CRX Si and the valve was sticking on one cylinder and it was like 180-180-0-180 lol...

l0l yeah that was tight shit

the honda dealer told me today that no honda(or anycar that they had ever seen) hit over 175 on a compression check i was like i have seen many hondas with 180 -200+ compression when tested but i may just be stupid. l0l was not able to get a leak down test today no one i contacted could get me in so maybe tomorrow i can get it done btu everyone i have talked to thinks that 200+ compression is way to high for any motor but i have seen many hondas with that high compression when tested

anyone at all? any ideas? anything?

[91civichatch2571]

Originally Posted by 91civicDXdude

I first thought it might be valve seats, but when it hits 120-140psi, it holds the pressure and doesnt leak out like you would figure if the valves werent closing.

With a compression gauge, it will always hold pressure once you crank it a couple times. No matter if its at 80 or 280. Thats why you gotta push that little button to release the pressure. As for the problem though, 120-140 psi sounds a lot more realistic than 235. engines with high compression pistons might get up towards 200 but a stock definitly shouldnt. How many times do you crank the engine over? should be like 5 or 6. Anyways, do the leakdown and see what you get.

[]{iwi]

10.2 to 1 is high compression i thought and i am checking it right. stock gsr have like 240 when comp. checked so i sould have close to that if all is well

DXdude what does your ls do with a compression check its like 200 right

[91civicDXdude]

yep. i hit 190-200.

120-140 is very low. even my 1.5L's had 180

[]{iwi]

anyone willing to take a stab at this or what

[Dweezil6969]

Are you doing the test with the throttle open or closed? If your not opening the throttle all the way the numbers are going to be lower.

[91civicDXdude]

Originally Posted by Dweezil6969

Are you doing the test with the throttle open or closed? If your not opening the throttle all the way the numbers are going to be lower.

the numbers wont be lower, it will just take longer to get a maximum pressure reading since with the throttle closed there is a lot less air to compress.

and BTW, of course the throttle was open.

[]{iwi]

^^^ yep i even tried it with the intake completely off and wot even though i knew it would not make any diff.

[]{iwi]

...

[]{iwi]

up for ideas

[]{iwi]

no one has any input on this ...