Throttle Body Bypass

[JDOwen2]

I have a 95 SC300. I've been reading about regular service issues and read that you have to remove throttle body to change plugs. I also see that you have to drain radiator before you do so because the throttle body has coolant hoses routed to it. I'm guessing this is to heat the air/fuel mixture for emissions. Anybody bypass the throttle body by connecting the coolant hoses? This is a common performance enhancement on TPI Chevys.

[Bubbles]

hmm... let's see... the 1993 repair manual says... Remove throttle body (that's a pain), then take off plug wires, then take out plugs with 16mm socket. Torque them 13 ft-lbs. That's the general stuff. You don't need to drain coolant.

[AWJ]

You can bypass the throttle body. Mine is.

[SCoupe]

hmm... let's see... the 1993 repair manual says... Remove throttle body (that's a pain), then take off plug wires, then take out plugs with 16mm socket. Torque them 13 ft-lbs. That's the general stuff. You don't need to drain coolant.

In my 93 SC3 manual, right after it says "Remove the throttle body", tells you to "See page FI-46" on how to do it.

Page FI-46 states in bold capital letters: 'DRAIN ENGINE COOLANT".

Having said this, I'm begging to hear that is not necessary from someone who has done this, before I go launching into my own vehicle.

Also, regarding the bypass, can someone explain the upside to bypassing and connecting them up? Is this mod worth making/any negative side effects?

Just wondering about this, not challenging anyone. Thanks. B)

[AWJ]

It is adviseable to drain the coolant at least a little. I'd rather drain it than have antifreeze pooring over my valve cover.

By passing the throttle body in theory and probably in reality, allows the air passing through the throttle body to be cooler because engine temp cooling fluid is not running through it.

[SPORTcoupe300]

Plus the coolant doesn't have to travel as far (I think) so your water pump gets a bit of a break.