The throttle body (TB) was next up on the agenda for an overhaul. Here’s a picture of what the TB and Mass Air Flow (MAF) sensor looked like when I first removed them. Pretty rough looking, but I saw it as an easy challenge compared to what I had to do to the engine block to get it shiny.
And here’s what lurked behind the throttle plate… enough carbon to choke an industrial incinerator. Clearly oil was getting into the combustion chambers via the PCV port and leaving a mess in the intake.
This is the other half of the TB which I call the adaptor since it bolts between the TB and the plenum. It was pretty crudded up with carbon too. Little did these Pigpens know that no matter how baked on their carbon or how corroded their exteriors were, resistance to my buffing wheel would be futile.
After stripping down of all the sensitive doo-dads like Idle Air Control valve (IAC), Throttle Position Sensor (TPS), throttle plate, and various seals, they were ready for the glass-beading booth. I spent about 6 hours sanding them smooth again (at least as smooth as I had the patience for!) and polishing them with various buffers. There’s lots of nooks and crannies on the TB so it’s impossible to get them all, even with a Dremel:
With the dirty work done, the rebuilding phase could start. Once the throttle plate was in place, it was secured by two tiny screws that were glued in place with Locktite… they’re the last thing you want to have vibrate loose!
Then the TPS and IAC valve were re-installed:
Then the throttle body adapter was screwed to the intake plenum:
And finally the throttle body was bolted to the adapter using a new gasket:
Here’s what the completed assembly looked like once installed: