Emergency! Compression figures?
- Thread starter kaj
- Start date
ball park is perfect. my mileage is unknown.. but i just needed some type of reference. then i can concentrate on the numbers being equal. thanks!
correct.
does anyone know what number is normal for them to jump to after the first crank?
90-100ish?
C
coach
Guest
First off...disconnect the wire going to your ign module. Next crank it until it stops climbing. I just did a check on my 24k mile engine and all were 145-155, and I have beat the snot out of it.
:biggrin:
:biggrin:
yes, thank you. i know how to do the check. i just don't know what the numbers need to be. i'm trying to figure out where the needle should jump to initially, now that i know the peak number. and i am aware they need to be relatively equal on all cylinders.
GARY HARVEY
Member
- Joined
- Aug 17, 2001
After a compression test..
You will get a better idea of the situation using a leak tester and testing at a warmed/hot temp, which is also positive for a compression test.
As for a percentage differential, keep in mind your history with other passes.
Have your times started to increase?
10% differential is (a little) on the problem side for a hot rod but acceptable for a daily driver.
Do you have any numbers from the first build as reference or time when first
(started) running this engine (bought or build spec info sheet)?
You will get a better idea of the situation using a leak tester and testing at a warmed/hot temp, which is also positive for a compression test.
As for a percentage differential, keep in mind your history with other passes.
Have your times started to increase?
10% differential is (a little) on the problem side for a hot rod but acceptable for a daily driver.
Do you have any numbers from the first build as reference or time when first
(started) running this engine (bought or build spec info sheet)?
You will get a better idea of the situation using a leak tester and testing at a warmed/hot temp, which is also positive for a compression test.
As for a percentage differential, keep in mind your history with other passes.
Have your times started to increase?
10% differential is (a little) on the problem side for a hot rod but acceptable for a daily driver.
I do a leak-down if the compression test is irregular. I have a comp test gauge in my garage. A leak-down requires a drive to the shop, which I am currently unable to do.
Correct. I've been doing these for years. Very familiar with the process.
Is there a specific way to kill the fuel pump? I was just gonna pull a fuse.
Pittsburghkid
Displacement Replacement.
- Joined
- Mar 22, 2009
just unplug the ecm from the positive battery cable, or just pull the plug right underneath the license plate under the rear bumper.
Reply
My preferred method is a leak down test. 10% or lower is ideal. If a problem is indicated it can be easier to diagnose & a better idea of engine wear. Cutting the oil filter open & looking for any metal debris also is helpful in spotting lower end problems.
My preferred method is a leak down test. 10% or lower is ideal. If a problem is indicated it can be easier to diagnose & a better idea of engine wear. Cutting the oil filter open & looking for any metal debris also is helpful in spotting lower end problems.
