Symptoms Of A Blown Throttle Body Gasket?

[GD51LA]

Series three r33gtr 57k no mods part from turbo back with 100cell 5" body (surflow) cat. It's making a lousy 162awk. Can you figure the problem?

My car seams to be loosing power some where. I had the turbos checked out and they are working fine but it seams like the boost isn't entering the motor for som reason. the standard boost tacho is reading less than normal. We plugged her up to the dyno and it said the boost was at 10 and 12psi but the standard gauge is reading less than that? Why? I compression tested the cooler/pipes, no problem there. If one of my plenum gaskets was leaking what symptoms will it have? There is a hiss coming from under the plenum, when I turn off the car the engine stops before the hiss stops?? a few mechanics had a quick look at it (they were busy), they sprayed carby cleaner all around that are but couldn't locate the hiss. Like I said it was coming from under the plenum..

On a cold night the car sometimes looses most of it's power, like it takes ages to reach redline. At the same time the boost reading on the standard tacho also goes right down? Is the boost leaking out around the plenum you think?

The cat is fine, no turbo wheels in there.

She is completely standard,except for turbo back exhaust (standard boost too)

[STATUS]

spray carby cleaner around gaskets, if idle changes you have a leak.

could be one of the vac lines off the vac reservoir under the plenum, bov source etc..

try removing vac lines to one turbo actuator at a time, just to make sure both turbos are in fact working, the power seems about right for one with a dead turbo.

Or check the two vac lines which leave the vac reservoir, one goes to the bov the other (i cant remember right now) but if they are mixed the bovs open under boost and limit power to about what your seeing.

[DVS JEZ]

on the dyno try a decat pipe too see if it frees things up a bit. we made an extra 45kw on a silvia that had a highflow cat on it.

[GD51LA]

The cat is new, I also removed it to see If it's blocked and it wasn't.

I disconnected the cat and drove around the block and nothing changed.

Two work shops said a good 100cell 5" body cat is around $500, not the $300?

[DVS JEZ]

Have u checked the stock rubber intakes? They might be sucking in. Check the Metal coil inside is still located correctly.

[GD51LA]

I checked the coils in the rubber boots they are ok

When I get a chance I will try Locate the hiss from under the plenum. If that doesn't work I will move to the next thing

[BoostdR]

I checked the coils in the rubber boots they are ok

When I get a chance I will try Locate the hiss from under the plenum. If that doesn't work I will move to the next thing

The idle control solenoid is under the Plenum. Usually makes a hiss. If you were leaking boost your car would be running rich.

Check cam timing

-if its retarded

-if the inlet and exhaust cam are aligned correctly with the crank

Check if the spring is inside your inlet pipe (after AFM) It stops the hoses sucting closed under boost.