no miss under load

[therealm0rh0us]

2000 sw2 p0301
its got 75 psi in cylinder one
i guessed after that it has a cracked valve or sumthin
but it only misses at idle and not under load if youre driving you dont even notice it
wanna know what yuse thinks

[project92SC2]

are you sure it's a mis-fire? it could be an exhaust leak.
is SES (saturn tunerz) light on? If not, then check for an exhaust leak....
if so, do a complete tune-up... plugs wires coils and icm.

[brokenheadz2003]

yea gotta be a leak somwhere for it to be showing only 75lbs.....any cracks in the intake or exhaust manifolds?? is the injector snug in its home, are the clips on the injector??

[project92SC2]

right. because 75lbs is low for cylinder pressure. It should be between 120-160 at all times.

[S.Bretz]

Serivce limit is 185-180.....THAT'S THE LOWEST IT SHOULD BE

[project92SC2]

That is highest compression (psi) allowed isn't it?

[slowion2]

no I think highest for stock is 205 or 210

[saturnspeed_12]

same situation with my brothers 3.4. idles bad and misses on low rpms. get moving a bit and its gone. i would bet head gasket. possibly stuck compression ring

check inside your valve cover for foam after it runs. you may have to pull the valve cover off as that metal shield might not let it get up there.

[therealm0rh0us]

i need to bring it back to the shop and parkit
check the cylinder next door and then pull the cams and pressurize the low cylinders to confirm whats bad and ill post back