VERY dirty throttle body (inside)

[2000bravada]

I recently took a look inside my throttle body - talk about dirty! Carbon everywhere, muck on everything. I used a can of throttle body cleaner to spray it out (only removing the intake hose/filter assembly from the top to access below the throttle plate).

Am I right in assuming that this is caused by pre-ignition forcing the combustion up through the intake valves and into the throttle body, and that this will lead to the rapid deterioration of my engine? If so, any suggestions of how to fix this? Yeah, I've upped my octane, with little change...
z

[JTrujillo86]

My mom has 1999 Blazer which I just cleaned the throttle body out on. It was sticking REALLY bad. I don't know what the effects are, but I really don't think that the setup of the T.B. helps. To me, it seems that since sits on top of the engine in a horizontal fashion, it makes it easier for stuff to build up within in it, on all sides of the plate.

Jeremy

[Chris Stewart]

The residues on your throttle body is caused by oil vapors from the crankcase gasses (blow-by) used by the idle air control valve (IAC) to control idle speed condensing onto the throttle assembly at the butterfly. Most of these gasses are admitted with the PCV valve and some go through the IAC. You can spray'em clean or spray a rag and wipe the residues off. I use the spray the rag method to keep the cleaners off the CPI and plastic fuel lines inside my '92 intake manifold.
On TBI & SCPI motors, spray'em clean every now and then.

[2000bravada]

see, here's the thing. It isnt' just the throttle plate, but it's the entire intake manifold - really everything above the valves. A rag isn't what's needed to clean this... try compressed air and solvents, or a complete disassembly of the top end.

Plus, with my loss of power during aceleration, I really think I'm getting some kind of blowby through the valves...

A possibility?

Thanks.

[Chris Stewart]

Hold up, those residues are stuck to the inside of the manifold. If you loosen up that junk and try to burn it, you'll foul the plugs and junk up the O2 sensor & catalytic converter. There's no hurt in just letting it sit there. If you just can't stand it, remove the entire intake manifold an clean it away from the motor...then do it again every year.

Concerning the leaking intake valve, if it leaks during the ignition stroke, won't it light off the extremely volatile air/gasoline mix inside the intake port and making popping noises?
I'm having a little power loss on my '92 CPI right now but I think it's the fuel pressure...it's jes' barely 50 psi and the spec is 55-57psi.