this has been making a very noticible hiss at times, other times it doesnt. I'm sure at one time there was a vac hose on it, but i dont know where it went or what it does. any clues? 88NA, you're looking at the back of the TB from the passenger side.

anyone?

thats the thermowax. When the engine is cold, it will route the vacuum to the choke actuator on the front of the TB. When the engine is warm it should be closed.

it closes the double throttle when the engine is cold

so by it sucking, it's not doing any damage, correct?

that should have coolant flowing through it shouldn't it???

I think, if you hear it sucking, the two vac lines on the bottom are hooked up backwards, and the valve is an open vacuum leak. Swap the 2 lines and see if anything changes.

will do.

The pics I can find in my Haynes show that the vac line closest to the TB goes to the intake mani, and the line farthest from the TB loops over to the double throttle actuator on the front of the TB. I cant tell from your pic where you have the lines going to.



sidenote: If you dont want to deal with all this BS, you could do the TB mod to remove the double throttle plates. When I did mine I removed the plates, the actuator, and the valve you are messing with, however, I left the therrmowax in to help with cold starts. You have to leave the coolant lines going to the TB, but you can eliminate some of the restrictions. If I remeber right, a 3/8 NPT plug will fit perfectly in the hole where the plastic valve came out of.

i switched the hoses over, but i havent noticed a difference, aside from the fact that there is no audible vac from that thingy. If indeed they were on wrong, or on wrong now, it's not going to cause catastrophic engine failure, is it?