Fuster_Cluck

JohnnysEG stopped by tonight with his new compression tester gadget he got for X-mas. Thanks again man

So, I wanted to check the compression on my 96 Cx that I picked up last week. This way I know if it's worth tuning up for daily driving or pulling the motor and getting a swap. We pulled the ECU fuse, removed all the spark plugs and did the test.....

What all 4 cylinders showed:



Here's a vid (digital camera) of us doing the compression on my Cx. We read how to do it from c-speed's "How To"

4.51 mb **right click save as** 4.51mb

http://www.we-todd-did-racing....DE%3D

So, how'd we do?

My (FastAssH22Accord) bro's 95 F22 Accord....

8.90mb **right click save as** 8.90mb

http://www.we-todd-did-racing....DE%3D

Did we do the compression test correctly? I find it odd that all 8 cylinders tested showed at least 180. My bro swore the thing was broke after we did his 220K+ motor One of his cylinders showed 205

As always thanks for any feedback

Street Ghost

*didn't watch the vids*

But this is how I do mine. I pull out all the plugs, disconnect back-up fuse, disconnect all the distributor plugs, floor the gas, and crank it about 7-8 times or until the person holding the gauge tells me that the needle stopped moving.

180psi across all four cylinders in the Sohc is pretty good. That's what my d16z6 with 90k+ miles pulled.

khmboostedeh2

crazy, i got a compression tester identical to that one 2 days ago and did mine. i got all even #s too. 190 190 190 195. as opposed to how u did it, i held the ignition however, i dont know which is the right way.

(94 b18b1 btw)

Street Ghost

*just watched the video*

instead of cranking it one by one, you should just hold it and let it crank for about 7-8 times or until the needle stops moving. i've never seen anyone do a compression test the way i just saw u do it.

Fuster_Cluck

Damn!!!!! I never put the gas to the floor

I remember reading that on C-speed now that it's mentioned

Could that really make a difference? $hit!

khmboostedeh2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Hatch &raquo;</TD></TR><TR><TD CLASS="quote">Damn!!!!! I never put the gas to the floor
!</TD></TR></TABLE>

big differance i believe

ccivic

.. You're supposed to hold the ignition on, and let it crank about 7-8 times. And yes.. hold the pedal to the floor, although I do not think it will make much of a difference.

Luserkid

You should have held it because then you could see if it will hold the compression. But those numbers are really good. Nice Camera. A310?

Fuster_Cluck

"press the gas pedal all the way to the floor, this is very important. While the pedal is pressed down, turn the ignition on and crank the motor over 5 times."

I was going to go buy $175 worth of parts for a full maintenace / tune-up tomorrow. Guess instead I'll be doing another compression test on the motor :bigF**kinHammerAcrossMyHead:

camera is a Canon Powershot A70

Kamin

look the numbers of a compression test arent that important. the variation from cylinder to cylinder is more important. 2 identical testers can give significantly different numbers on the same engine.

Fuster_Cluck

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kamin &raquo;</TD></TR><TR><TD CLASS="quote">look the numbers of a compression test arent that important. the variation from cylinder to cylinder is more important. 2 identical testers can give significantly different numbers on the same engine. </TD></TR></TABLE>

So, these things are not accurate? Just consistent? :a little confusede & tired as $Hit:

...off to bed

Kamin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Hatch &raquo;</TD></TR><TR><TD CLASS="quote">So, these things are not accurate? Just consistent? :a little confusede & tired as $Hit:

...off to bed </TD></TR></TABLE>
pretty much, each gauge can read different but they read off consistently lol

the number is never important (unless its incredibly low or high) just the variation

like if 1 tester gives

165 165 160 170 the variation is about 10psi across the board
the next testef can give

150 150 145 155 variation is still 10 but the numbers arent the same.

not only that but many factors go into a compression test like altitude, temprature (engine and air) how you performed the test etc.

so never compare compression test results with someone else, always just use your numbers for what they are.

CivicEJ1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by _Edge.ONE &raquo;</TD></TR><TR><TD CLASS="quote">*just watched the video*

instead of cranking it one by one, you should just hold it and let it crank for about 7-8 times or until the needle stops moving. i've never seen anyone do a compression test the way i just saw u do it. </TD></TR></TABLE>

yeap

Fuster_Cluck

Also, heard motor should be warm. Is this true?

**Preparing for another compression test**

Deemeetree

Indeed, what mainly matters is consistancy.

FERIOkid

you are not supposed to let it crank 7-8 times you are supposed to let it crank 4-5 times. Thats all you should need, my d15b7 read 175 across the boards with 85k on it. The people above me are correct when they say that the diff. in the numbers is really all that matters. A kid in my class had 205,190,95,150 so hes doin pretty bad

The Steps we use in school (New England Institute of Technology)

1. disabe fuel (ecu fuse) disable ignition (distributor plugs)
2. remove and lable all spark plugs and observe their condition
3. install guage correctly
4. crank the motor 4-5 times with the gas pedal to the floor

thats pretty much it...inform me if i forgot anything

Fuster_Cluck

Can someone explain the "gas pedal to the floor" and why it's important?

AutoXer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jeterkm02 &raquo;</TD></TR><TR><TD CLASS="quote">

big differance i believe</TD></TR></TABLE>

Yes, very big; read towards the bottom:

https://honda-tech.com/zerothread?id=1083730

I went from 150 to 210.

AutoXer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Hatch &raquo;</TD></TR><TR><TD CLASS="quote">Can someone explain the "gas pedal to the floor" and why it's important?</TD></TR></TABLE>

Because on the intake stroke, without the gas, the throttle body is closed. That means, it can only pull so much air in during the stroke. Then on the compression stroke (what you're testing) there is less air volume, wich produces a lower pressure withing the cylinder.

Fuster_Cluck

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EX_AutoXer &raquo;</TD></TR><TR><TD CLASS="quote">

Because on the intake stroke, without the gas, the throttle body is closed. That means, it can only pull so much air in during the stroke. Then on the compression stroke (what you're testing) there is less air volume, wich produces a lower pressure withing the cylinder.

</TD></TR></TABLE>

So my compression numbers can only get better??

FERIOkid

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Hatch &raquo;</TD></TR><TR><TD CLASS="quote">

So my compression numbers can only get better??

</TD></TR></TABLE>

in a nut shell yes

JohnnysEG

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Hatch &raquo;</TD></TR><TR><TD CLASS="quote">Can someone explain the "gas pedal to the floor" and why it's important?</TD></TR></TABLE>

what he said........i didn't think that it mattered about the pedal thing either cuz the fuse was pulled, oh well guess we will have to do it again jonathan

Fuster_Cluck

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JohnnysEG &raquo;</TD></TR><TR><TD CLASS="quote">

what he said........i didn't think that it mattered about the pedal thing either cuz the fuse was pulled, oh well guess we will have to do it again jonathan </TD></TR></TABLE>

If you're free this weekend I'm up for it again. The numbers can only get better from what is being said in this thread This time we just turn the key over and hold it for 5 or so turns.....

I'll be tuning the motor up for the start of daily driving next week. I can't wait

G U E C O

your not suppose to hold the gas pedal down and dont turn yoru ignition on and off, keep it on until 7-8 cranks

_Cyclone_

What they teach in trade school is that you only hold the gas pedal down to the floor to disable the fuel injectors. Pulling the ECU fuse is not recommended. However I see EX_AutoXer's point about the air volume in the cylinders being restricted by the throttle body butterfly being closed if you don't hold it down. That's just what I learned from the powers that be...