i'm puzzled need some serious opinions - Performance Forum

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i'm puzzled need some serious opinions
Monday, February 25, 2008 3:57 PM
ok to start heres my mods
intake
pacesetter 4-1 header
2.5 piping after the cat
2.25 catco cat
dynomax super turbo single inlet and outlet muffler
upper and lower mounts
B&M shiftplus
JBP stage 2 cams
balance shafts removed
A/C delete
62mm TB
koni sport kit
completely gutted, only weighs 2400 with me in it (i'm 135)
ok now where im puzzled. with the mods listed i can run side by side with a cobalt ss/sc, along with many mid to low 14 sec cars.
did a random compression test on my engine while inspecting the plugs. pulled all the plugs and had the pedal to the floor.
results came up as follows:
cyl 1: 30psi
cyl 2: 30psi
cyl 3: 39psi
cyl 4: 17psi
technically it shouldnt run and if it did it should be blowing a huge cloud of burnt oil out the tail pipe.
?
any help just to help me figure out whats up
thanks



The one, the only, ME.
2465 lbs without me
141 hp @ 6300 (ran out of rpms)
123 ft lbs @ 5200
running lean on stock ECU
megasquirt here i come

Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 4:54 PM
yeah it would not be running at that compression. i think you ether have a busted guage or did the test wrong.



Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 5:03 PM
why did he have the pedal to the floor?



Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 5:05 PM
Has to be wrong get a differant tester and try again.

Push the petal down with all plugs out compression tester in one hole.
Turn it over with the petal down let it do about 5 turns then stop and check the gauge.

That has to be wrong.



Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 6:01 PM
Paul Tjepkes (N/A MADNESS) wrote:Has to be wrong get a differant tester and try again.

Push the petal down with all plugs out compression tester in one hole.
Turn it over with the petal down let it do about 5 turns then stop and check the gauge.

That has to be wrong.


yep thats how i did the test. and its a brand new gauge.



The one, the only, ME.
2465 lbs without me
141 hp @ 6300 (ran out of rpms)
123 ft lbs @ 5200
running lean on stock ECU
megasquirt here i come
Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 6:06 PM
Bigari Balsagna(04eco) wrote:
Paul Tjepkes (N/A MADNESS) wrote:Has to be wrong get a differant tester and try again.

Push the petal down with all plugs out compression tester in one hole.
Turn it over with the petal down let it do about 5 turns then stop and check the gauge.

That has to be wrong.


yep thats how i did the test. and its a brand new gauge.


Well if you did the test right, it's time for a leak down test.

EDIT: and as said before the car shouldn't be able to run at 30 psi.


Edited 1 time(s). Last edited Monday, February 25, 2008 6:08 PM


Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 6:11 PM
yea thats where im puzzled it shouldnt be running that well. even if it fails a leak down test to it shouldnt be running so good.
i know something isnt adding up i just cant think of what.



The one, the only, ME.
2465 lbs without me
141 hp @ 6300 (ran out of rpms)
123 ft lbs @ 5200
running lean on stock ECU
megasquirt here i come
Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 9:07 PM
are you reading the gauge wrong???? just a thought lol



Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 9:31 PM
Why stick the pedal to the floor?

Also how are you doing the test?


Gilles
2.3 Ho

Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 9:43 PM
You always do compression test with the throttle open all the way. In order to accurately test compression, the cylinder has to be able to get air. It can't compress something its not getting.

It's like I saying I wanna see how many twinkies I can eat.... you need to have some twinkies before you can see how many you can eat.



Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 9:45 PM
As for the original problem... did you disconnect the injectors before running the test? If you didn't you may have washed the walls.




Re: i'm puzzled need some serious opinions
Monday, February 25, 2008 10:55 PM
I've NEVER did a compression test with the pedal to the floor. Always without it. Never had 1 problem and good reading. The engine still gets air. It's not under vacuum when the throttle is closed. The IAC is still open and the throttle never shut completly. There's always a gap.



Gilles
2.3 Ho

Re: i'm puzzled need some serious opinions
Tuesday, February 26, 2008 6:10 AM
congratulations

the correct way is still with the throttle wide open



Re: i'm puzzled need some serious opinions
Tuesday, February 26, 2008 8:22 AM
Does it make a big difference on the gauge?


Gilles
2.3 Ho

Re: i'm puzzled need some serious opinions
Tuesday, February 26, 2008 9:59 AM
no idea. Ive always done it the right way.



Re: i'm puzzled need some serious opinions
Tuesday, February 26, 2008 3:03 PM
ok after getting suggests from ecotecforum also and talking with a few people, came to find out should've had the engine at full operating temp (i always thought you couldnt pull the plugs when it was warm) so i warmed it up and retested it and came up with:
cyl 1: 175
cyl 2: 190
cyl 3: 180
cyl 4: 190
much better. makes sense though to have it warm then everything's seated and swelled properly, etc.

much thanks for all the help and suggestions



The one, the only, ME.
2465 lbs without me
141 hp @ 6300 (ran out of rpms)
123 ft lbs @ 5200
running lean on stock ECU
megasquirt here i come
Re: i'm puzzled need some serious opinions
Tuesday, February 26, 2008 3:08 PM
Bigari Balsagna(04eco) wrote:ok after getting suggests from ecotecforum also and talking with a few people, came to find out should've had the engine at full operating temp (i always thought you couldnt pull the plugs when it was warm) so i warmed it up and retested it and came up with:
cyl 1: 175
cyl 2: 190
cyl 3: 180
cyl 4: 190
much better. makes sense though to have it warm then everything's seated and swelled properly, etc.

much thanks for all the help and suggestions


that sounds about right



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