well today I decide to work on my project, JRSC 98 prelude, before I started the project, I jperformed a compression test about 1 1/2 months ago, my compression checked 170 all across, that was a good compression as I figgured, then today as I redid a compression check, it reads 120, this cannont be good I know, so now I am going to return it to NA. But I know some cars minum compression to start combustion is about 100psi, but this is under normal compression ratio 8:1 or so. but I am not sure if the prelude high compression ratio will this apply, does anyone know, if 120 is the limit for the engine to start??? or is the engine dead

and I checked the basics

spark charged battery

and plenty of fuel.

 

put a small amount of oil into the cylinders and retest. Also, did you make sure the throttle was in the WOT position while testing? And also run the test after the motor has been brought up to operating temperature.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Giant_Bean &raquo;</TD></TR><TR><TD CLASS="quote">put a small amount of oil into the cylinders and retest. </TD></TR></TABLE>
X2 If compression improves its ring to wall seal

What engine management?

 

doesnt make any sense...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98vtec &raquo;</TD></TR><TR><TD CLASS="quote">doesnt make any sense...</TD></TR></TABLE>
What part?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mltv &raquo;</TD></TR><TR><TD CLASS="quote">But I know some cars minum compression to start combustion is about 100psi, but this is under normal compression ratio 8:1 or so. but I am not sure if the prelude high compression ratio will this apply, does anyone know, if 120 is the limit for the engine to start??? or is the engine dead

and I checked the basics

spark charged battery

and plenty of fuel.

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

If your talking about that part^^, I dont know what he is trying to say either. But if it dropped 50psi in 1 1/2 months and hes using a KNOWN GOOD Compression tester, than there is apparently an issue.

More info on build/tune?

 

first off, thanks for replying....

okay the build is stock

I did put oil about a cap full of Mobil 1 full synthetic on cylinder number one, the compression did go up about 30 psi. so cylinder number 1 read 150 and the rest read 120.

managment system is Emanage blue. the car did start without a probelm a week ago, but a complete week later, it took a crap, and i find myself here.

wide open throttle for the compression test??

I believe i picked up a good compressor test, not much choice where I went.

 

[QUOTE=mltv

I did put oil about a cap full of Mobil 1 full synthetic on cylinder number one, the compression did go up about 30 psi. so cylinder number 1 read 150 and the rest read 120.
[/QUOTE]

To clarify you only did the oil test to cyl #1 correct?

If so sounds like the mad professor has to replace the piston rings you fried

Just kidding, but it does sound like sleeve/ring damage, did you use a wideband when tuning?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H22Luda720 &raquo;</TD></TR><TR><TD CLASS="quote">


If so sounds like the mad professor has to replace the piston rings you fried

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

"now we got to rip apart the block and replace the piston rings you fried!!!"