Useless compression test write-up
05-21-2009, 03:01 PM
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Useless compression test write-up
IBTL :-P
I saw alot of threads started regarding compression tests in the past few days but when I searched "Compression Test" in the Integra forum I did not see any immediate results with pictures (For the ones of us that need pictures). So I was doing a comp test on my Integra I just picked up and thought I would snap a few pictures.
*Disclaimer*
- I do not do this the same way as most people. I have a remote starter set up so I can power the starting system without energizing the ignition. Other people prefer to energize the ignition/fuel system and just remove the appropriate fuses to prevent the injectors from firing.
0. Preparation: Get out your tools and hire a helper:
1. Remove spark plug wires
2. Remove spark plugs (Some people remove 1 spark plug at a time, but I feel that is useless because the injectors are not firing and each cylinder is by itself anyways) Also if you feel iffy about the injectors firing while you try to turn the car over you can pull an ecu fuse or d/c your fuel pump.
3. Select the correct adapter for your compression tester (In this case, the threads on the air line is sufficient. I got this tester from the local Auto-zone other testers will usually come with more adapters for different vehicles.
4. Thread the hose into the cylinder head, this part is usually pretty easy just make sure its tight but don't force it or the hose can come loose from the fitting after alot of abuse. Then attach the Gauge like so:
5. Ok, now you will crank the car (unsucessfully of course). You have to remember how many seconds you try to crank, I use either 5 or 10 sec per cylinder. You HAVE to use the same time interval per cylinder otherwise you cant compare the difference between cylinders. 5 seconds on one cylinder might be 150 psi, but at 10 seconds could reach 170 psi, but you cant compare cylinders that were tried on different time intervals. If the psi is lower than you want to see when cranking for 5 seconds, try 10 instead but go across all cylinders again.
Here is my gauge showing 150 psi:
6. Release the air pressure from the gauge and repeat for each cylinder.
7. Data breakdown..... In my example I had 150, 150, 150, 145; although low numbers (135 being minimum for B-series, I only had a variation of 5 psi (25ish being max deviation) Do not worry so much about what the numbers are, just that they are consistent.
Most of you will yield larger numbers across the board. But in my experience 150 psi is fine for modding, just need to keep my goals low when boosting
Hopefully nobody needs this write-up. It is a over complication of an extremely simple test. But alot of people new to cars do prefer to see pictures or 'write-ups' to get the confidence that they need. So maybe it helps more people than it annoys. Thanks
I saw alot of threads started regarding compression tests in the past few days but when I searched "Compression Test" in the Integra forum I did not see any immediate results with pictures (For the ones of us that need pictures). So I was doing a comp test on my Integra I just picked up and thought I would snap a few pictures.
*Disclaimer*
- I do not do this the same way as most people. I have a remote starter set up so I can power the starting system without energizing the ignition. Other people prefer to energize the ignition/fuel system and just remove the appropriate fuses to prevent the injectors from firing.
0. Preparation: Get out your tools and hire a helper:
1. Remove spark plug wires
2. Remove spark plugs (Some people remove 1 spark plug at a time, but I feel that is useless because the injectors are not firing and each cylinder is by itself anyways) Also if you feel iffy about the injectors firing while you try to turn the car over you can pull an ecu fuse or d/c your fuel pump.
3. Select the correct adapter for your compression tester (In this case, the threads on the air line is sufficient. I got this tester from the local Auto-zone other testers will usually come with more adapters for different vehicles.
4. Thread the hose into the cylinder head, this part is usually pretty easy just make sure its tight but don't force it or the hose can come loose from the fitting after alot of abuse. Then attach the Gauge like so:
5. Ok, now you will crank the car (unsucessfully of course). You have to remember how many seconds you try to crank, I use either 5 or 10 sec per cylinder. You HAVE to use the same time interval per cylinder otherwise you cant compare the difference between cylinders. 5 seconds on one cylinder might be 150 psi, but at 10 seconds could reach 170 psi, but you cant compare cylinders that were tried on different time intervals. If the psi is lower than you want to see when cranking for 5 seconds, try 10 instead but go across all cylinders again.
Here is my gauge showing 150 psi:
6. Release the air pressure from the gauge and repeat for each cylinder.
7. Data breakdown..... In my example I had 150, 150, 150, 145; although low numbers (135 being minimum for B-series, I only had a variation of 5 psi (25ish being max deviation) Do not worry so much about what the numbers are, just that they are consistent.
Most of you will yield larger numbers across the board. But in my experience 150 psi is fine for modding, just need to keep my goals low when boosting
Hopefully nobody needs this write-up. It is a over complication of an extremely simple test. But alot of people new to cars do prefer to see pictures or 'write-ups' to get the confidence that they need. So maybe it helps more people than it annoys. Thanks
Last edited by memorybox; 05-21-2009 at 03:08 PM.
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