BACKGROUND INFO: ok, i did a compression test on my boosted integra the other night and all the numbers were 155-165 except the number 2 cylinder which was ~130. i noticed that my boost gauge use to read about -20 vac at idle but not it only reads 15 (happend a little after i started boosting). Also, my valves sounds WAY out of wack.

my question is, can "unadjusted valves" that are way out of spec cause the slightly lower compression as well as the decrease in idle pressure? Im almost 100% certain my rings are not blown as i have 0 smoke or any color out of my exhaust.

-ryan

 

not sure about the valves, but I know if you have a varience that looks too high you are losing pressure.

Which basically meant that thw ring on the cylinder isn't holding. Doent need to have smoke coming out either.

I would try to CP test one more time, then do a leakdown test to see where it might be losing pressure.

goodluck

 

k, back to my main question

can unadjusted valves which are out of spec and can clearly be heard clicking cause lower compression numbers? I'm well aware of what all these compression numbers mean, what the spec variance between cylinders should be and believe me, i know about leak down tests and how doing a leak down test will not tell me if out of spec valve will affect the compression (unless i do the leak down test prior to and after a valve adjustment, whcih would totally defeat the purpose of this question and save me time)

-ryan

 

bump

 

I don't know if you can lose much pressure from valves that are out of adjustment, but why not adjust them? It's really not that hard to do.

 

Yes, out of wack valves can cause variation in compression tests and idle. I would assume that vacuum can be affected as well since you might have less air entering the system if the lash is too loose. But it sounds like you may have other problems. 130 is a big jump from 155-160. Do a valve adjustment and get it checked again.