Thermac Replacement?

[chevymotocross]

I have an 87 silverado with the 305 TBI engine. I notice that the flapper in the intake is not opening when the engine is warmed. The duct running from the right-side manifold, to the flapper on the intake is fine.

This has the "wax pellet" type thermac, not the vacuum operated kind. When I go to parts stores, everyone looks at me like I am from another planet when I mention this. I try the internet, and I notice none are listed at the parts stores websites.

Do they even sell these anymore or is this a junkyard piece? Can I keep it open with a zip tie or mechanic's wire for now?

[gmclowsierra]

i took and tack welded the flapper open on my bros truck. thats a 90 chevy 350tbi. the only reason that is there is to help on cold start up and to get a little heat to the injectors so they wont freeze in the extreme cold

[joe231]

In some states, they check these for proper operation during the emissions test.
you might check your local regs before you modify it.
if you don't have emissions testing in your area, disregard my previous statement

[chevymotocross]

I drilled little pilot hole at the top of the air cleaner tube, and another small hole at the flapper. I used mechanics wire to hold it open. Connecticut does not check for this device, but it's still there if I needed it.

Over the summer, I ran the truck with the flipped lid since many have told me it helps performance. It definately made a nice throaty sound. Well, I put it back the stock way, I will keep it stock! So much more torque with the closed oem setup. Plus, my K&N filter won't get dirty as quickly and now it will only suck in cold air.