Hey,
For my project I need the TB to be as small as possible, I'm thinking of cutting off the coolant passageway part of the stock TB and getting rid of the spring that opens the throttle slightly when it's cold. Anyone try running they're car just w/ the coolant hoses disconnected? I don't think it would really do anything except keep it from idling up.

any thoughts?
allen

 

Should be fine, that's what I plan on doing once I figure out my other problem.

 

I am doing that right now.

 

I have had the lines disconnected for 2-3 years. No problems here.

 

96sleeper
Does it take a while to warm up in the winter? No other issues at all?

thanks
allen

 

i have my coolant lines disconnected. it does not take any longer to warm up than normal. my car seems to warm up just as quick as others.

 

Can I ask why you guys disconnected your lines? Just to get rid of the extra lines?

allen

 

I had no room, or time to rerun lines during my swap. I saw it pointless for coolant to enter the TB.

 

I have no problems in the winter, I think some people have though. I disconnected mine to keep the TB from getting hot from coolant. It makes me more consistent at the track.

 

No problem at all. Just run a hose from the coolant inlet hard line to the return hard line (they are towards the driver side of the front valve cover, you'll see the bunch of hard lines down there, just figure out which is which). That bypasses the entire TB and back of the IM coolant circuit.

 

i removed mine for the same reason above, to keep the hot coolant out. i figured it might not make as much a difference having the composite/plastic manifold but i figured everything adds up.

 

why would Nissan (and every other manufacturer of a port fuel injected engine) want to warm the TB anyway?

 

I thought it was to keep the TB butterfly plate from freezing open. Up in MN you could have minus 20-30 air coming in. Imagine if ice formed somehow and kept the plate stuck open.

Actually that happened to me about 15yrs ago in an Olds Omega. An oil change shop left the wingnut loose on the airfilter. Something came loose and fell into the carb holding it wide open. I nearly ruined the brakes & trans trying to get it to stop as I couldn't turn off the engine while in gear or something IIRC.

 

sounds reasonable

 

On my TB the coolant heats up a type of valve that presses against the throttle spring opening it up slightly. When the coolant is cold it is held open slightly to make the idle go up to help warm up the car. When the coolant warms up the valve moves the other way closing the throttle allowing the idle to go back down like normal.

allen

 

Quality post. Informative! Thanks. I never knew how that worked!

 

That plunger thing is called a thermo-something or other. It works exactly as you described. You should definitely have no problem removing it. And since you already removed the EGR you don't have to worry about running the on to the EGR port on the UIM.

These are some shots of what I did to the TB and IM.




Can you snag some shots of the clearance on the firewall for me? That'd be sweet. You think you're going to have to move all the brake hardlines and wiper stuff? I realized that one hardline is for the clutch and one is for the EVAP stuff so there will only be two hardlines to deal with.

 

Broaner,
I'll update my original post on Freshalloy today w/some more pics that might help you out. Didn't have to move the two remaining hardlines, did cut up the IM pretty significantly though. Getting it welded back together tomorrow night. Turns out I have enough space to keep the cold start part of the TB too, just gonna leave it on the TB.

allen