I did compression test on my 99 prelude and not sure about the result. c1=130, c2=90, c3=150, c4=145. when i did this I only turn the motor three counts, enginge cold and throttle is closed. This is my first time doing this and not sure if throttle has to be WOT. MY plugs are kinda black little red only on electrode. When i pulled out the compression tester after test ii had some oil in the end. Is that normal? So, my next step was to pull out fuel injector connector while engine is running. When i Pulled out each connector on each cylinder it had some effect (like it lows the rpm more) however, on cylinder 2 fuel inj. conn. when i pulled out it had no reaction. The reason i did this test is that I have CEL lit and code say random misfire so decided to check fuel system.

Do you guys think that a bad injector on C2 causes this really off compression test result compared to c1,c3,c4?

How many times i have to turn the motor when doing compression test? some says 3 and some says 5?

I need help guys, give some ideas.. thank you

 

Bad injectors don't cause bad compression. Bent valves and dead rings do, among other things.

 

How bout valve clearance u think that would cause low compression?

 

if the valves are too tight it could, I would start off by redoing the test with the fuel injectors disconnected or the fuse for the fuel pump pulled and opening the throttle

 

My valve clearance seems like its loose man cuz they knock loud specialy on cylinder 2 when engine is cold. I don't see any leak as well on my car. Are you saying that it is better to take those fule injector connector when doing compression test?

How many time you have to turn the motor over when doing compression test?
When i did mine i dod not open the throttle and only crank the motor 3times, and some says 5 times?

 

Forget the injectors they have absolutly no berring on the results of a compression test. Injectors = fuel delivery Compression = pressure inside your cylinder

If you had oil on the tip of your compression tester that could be a sign of some bad piston rings or bad valve seal both could cause a poor compression reading. Next logical test for your case imo would be a leakdown test preformed by a shop.

 

so definitely not the bad c2-inj. causing this low compression? where are the vavle seals located at? do I need to pull the whole head?

 

when doing the compression test. the car must be completely warmed up. and u need to do alot more rotations like let the motor spin over like 5 or 6 times.