Are these compression numbers good?

[filluptieu]

I warmed up the car but its pretty cold outside and took about 15 - 20 mins to take everything apart and begin the test so im sure its cooled down a bit. Its a redtop sr20 stock everything minues exhaust

#1 119
#2 119
#3 120
#4 121

Is that okay? i thought it was a bit low but its stable. and i let it sit and the pressure held. ALSO this was six cranks exactly for each cylinder test.

[NINJASPY]

compression numbers are for comparison amongst each cylinder in a given engine.

so if they are +/- 3% of each other its usually pretty good, you are at a little more than 1% difference in each cylinder.

[ericb382]

Even though they are uniform, they are a little low... did you hold the throttle wide open while cranking? Did you either drain the fuel pressure or pull injector pigtails? Also, you should keep cranking untill it stops raising, even if it's more than 6 cranks.

[duffman1278]

That looks fine to me. I don't see an issue. All the numbers are really consistent as well.

[gotta240]

Those number are amazingly close to each other.....but kinda low. If i had to bet I would say one of three things

1. Your compression tester is bad and reading low(i've had that happen)

2. You didn't go wide open throttle

3. You didn't crank enough. I usually crank 10 or so times.

Sounds like motor may be good though

[filluptieu]

i just unpluged the injectors and didnt crank it to completely empty the piston i guess. and yes the throttle was wide open and i guess i need to crank it more ill try it again

[filluptieu]

Okay guys i redid the compression test with 9 cranks till the needle stopped and it was at 130 130 129 131. looks good right?

[shiftdrift]

yeah, that seems good. they are all close together. may be a tad bit low, but they are consistent.

[gotta240]

Try a differnent compression tester.

[robertftw]

If you disconnect the CAS sensor the injectors will not pulse FYI, easier to disconnect one plug. You couldn't have to crank it more than 5 times to get the compression readings.

[sidedrifts13]

What was the reason you decided to do a comp test?
I recently did a compression test on my sr because it was smoking and it was 165, 164, 167 and 165 so with that in mind i knew it had to be a blown turbo

[j87w]

Out of curiosity why did you do the test? Is your car low on power, burning oil, trying to diagonse a problew, ect?

[jspaeth]

Try a differnent compression tester.


Agreed, the numbers are very close together, so that is a very good sign....perhaps a compression tester issue.

[steve shadows]

looks like he didnt crank enough times

Try cranking 8 times for each cylinder and make sure to keep the throttle floored when doing the test

[filluptieu]

GOOD NEWS GUYS I re did the test and cranked it ten times till it stop rising and its 130 130 129 131. thnanks for all you help.

Also i did do a compression test because of a bit of white smoke coming out but it was jsut a old tank of fuel.... now it has stopped.