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just looking at causes to how engines develop low compression..

also does low comp in a cylinder cause missfiring?

i got results of

150

150

150

150

130

150

now would this mean rebuild? and would this cause missfiring?

rb25det s2

apexi turbo

power fc

nismo 550cc

eboost

z32

3inch turbo back (gutted 3inch cat)

hks exh cam gear

tube and fin cooler

splitfires

plugs put in straight from box not gapped

any ideas would be great!!! cheers in advance..

post-16535-1231232080_thumb.jpg

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i would be worried with number 5 cyl down 20psi compared to others, even if all cylinders were on 130psi i wouldnt by the car, not with a rb anyways as comp standard is 170psi,

as for making it loose compression, there are lots of things, but i know for a fact that its normally 5 or 6 that goes from memory? why would this be?

i thought you get alot more wear if the engine leans a bit, screws the rings and/or melts pistons,

JV

Souldnt be any obvious signs from those compression readings although you could be making more power if they were all 150 but mot by much.

Lost of peoples cyl 5 and 6 lose compression when they have front facing aftermarket plenums as they are deprived of air. Is your intake plenum stock?

Also if your missfiring is really bad and has been there for ages on the same cylinder could it have caused the low compression?

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