ANDREW280

Hey guys i have been having idling issues due to low engine vacuum ruled out compression, valves , and vacuum hoses idles low and vacuum is at 5 inhg we have come to the conclusion that it is a bad intake manifold gasket as it runs better after it gets warmed up (manifold expanding from heat from exhaust manifold) also ruled out the air reg. does any body know what idling engine vac should be? I would guess that it is the same as any other car 18-22 in hg, also can the intake manifold gasket be replaces separately without taking off the exhaust manifold?
any info would be much appreciated
-Andrew

NismoPick

The gasket is all one piece. The how-to is detailed in the Haynes, FSM, and we even have a write-up in our Gen Tech Area.

R&R of the turbo manifold gasket is a lot more fun.

ANDREW280

it is a turbo also do you know what kind of vac i should be seeing?
Andrew

NismoPick

15-20in hg is normal when cold idling. I suggest taking everything apart on the intake while it's off and inspect all hoses, connections, and o-rings. You can also deep clean everything as well.

ANDREW280

FINALLY!! figured it out my dad didn't adjust the valve clearance correctly 10 years ago when he did the head and we were using a bad compression gauge so got a new one 90 psi in all 6, adjusted the valves and the z runs like new great vac and 135 psi in all cylinders cold. Im so happy everything is working as it should now thanks for all your help! Now its time to sink some serious money into her!

FricFrac

WTF is up with your weather! I'm moving out until Spring shows up here on the Wet Coast... sorry completely off topic...

Nice find on the valve adjust and the faulty gauge

ANDREW280

Oh buddy im loving it, perfect weather to be working in the garage not to hot not to cold