D2 Throttle body
- Thread starter MTNHDWR
- Start date
I needed to be reminded of that thing. I'll be picking one up soon. It's nice when people put the effort in to improve a design, and even better when it's done here in the US.
Cheers,
Kennith
I never knew that I assumed it was cold air.
It never gets very humid in Oregon or the west coast for that matter. My results probably have to do with that.
I already bought the replacement part from AB/BP, first thing. It is not a issue about money, it is about the neccessity of the part.
Since, I also bought a TB gasket, I will be replacing the part, wondering if worth the effort to reconnect the cooling system through it. Thanks for everyones input.
Since, I also bought a TB gasket, I will be replacing the part, wondering if worth the effort to reconnect the cooling system through it. Thanks for everyones input.
I've long understood that ambient air temp is only one factor in throttle icing, secondary to ambient humidity. Venturi effect, etc., etc., etc. But the wikipedia article linked above speaks to the phenomenon in carburetors, not fuel injected systems. In fact it goes on to say "Engines equipped with fuel injection do not require carb heat as they are not as prone to icing - the gasoline is injected as a steady stream just upstream of the intake valve, so evaporation occurs as the fuel/air mixture is being drawn into the cylinder, where metal temperatures are higher." There is no fuel vaporization at or near the butterfly.
I'm not enough of an expert in fluid dynamics to speak to the other elements mentioned in the wikipedia article - the drop in pressure and increase in airflow speed in the intake - especially given the design of the Bosch intake where the diameter of the passages is relatively constant from the airbox to past the butterfly.
That said, as P.T. likes to point out, the engineers probably thought they had good reason to include the TBH.
I've always been in the camp of replacing, not bypassing, but I'll admit that when I was trying to track down a minor, elusive coolant leak a year ago I bypassed mine to eliminate it as a cause of the leak and have since been too lazy to reattach it. Redrover seems to keep me busy with more urgent tasks. But I live in the humid South so perhaps this thread will prompt me to connect it again this weekend.
And I love the Falconworks fix. But I don't love it to the tune of $160. Their explanation, however, explains why the LR TBH kit includes the plate and not just the gasket.
I'm not enough of an expert in fluid dynamics to speak to the other elements mentioned in the wikipedia article - the drop in pressure and increase in airflow speed in the intake - especially given the design of the Bosch intake where the diameter of the passages is relatively constant from the airbox to past the butterfly.
That said, as P.T. likes to point out, the engineers probably thought they had good reason to include the TBH.
I've always been in the camp of replacing, not bypassing, but I'll admit that when I was trying to track down a minor, elusive coolant leak a year ago I bypassed mine to eliminate it as a cause of the leak and have since been too lazy to reattach it. Redrover seems to keep me busy with more urgent tasks. But I live in the humid South so perhaps this thread will prompt me to connect it again this weekend.
And I love the Falconworks fix. But I don't love it to the tune of $160. Their explanation, however, explains why the LR TBH kit includes the plate and not just the gasket.
Then a paragraph later it says "Some multipoint injection engines route engine coolant through the throttle body to prevent ice buildup during prolonged idling. This prevents ice from forming around the throttle plate but does not draw large amounts of hot air into the engine as carburetor heat does."
The throttle body is not a carburetor and has no venturi. It is not susceptible to icing like a carburetor is.
Yes, I was just pointing out that the T/B heat on a Disco is not for the purpose of preventing carburetor ice. It's part of the extreme cold weather kit like the heated windshield. It does serve a purpose but you're not going to get an iced up throttle on a Disco in Alabama, I don't care how much humidity there is in the air. Now if you were flying an 85 hp Luscombe with an updraft Stromberg carburetor yes, there is a very real chance of experiencing carb ice.
FWIW in my experience even with the upgrade kit it still ends up leaking eventually. If you live in North Dakota you could treat it like a periodic maintenance item that you just do every couple of years or, if you live in Alabama or California, you could just bypass it.
I have read posts of a throttle body freezing up on a D2 and having a stuck throttle cable but has this been verified. The reason I ask is I know that some D2 had a recall fix on throttle cables that could become stuck. Maybe this was the actual problem.
The recall was done on my 2000. My throttle body froze open 3 times when I by-passed it. All on days when the temperature was in the mid to low twenties and after sitting all night.
After driving about 2 miles or so the throttle body wouldn't close when I let up off the gas peddle. After some heat soak from the engine it would unfreeze and become responsive again.
You guys believe what you want and do what you want, I don't care but I have had it happen to me.
Maybe it was dirty which caused the sticking....... I've certainly seen worse than above and could see it sticking from all that crap, but beyond that plenty of other vehicles on the road in cold climates DO NOT have anything keeping the throttle body warm and they don't stick during colder weather.
Maybe it was dirty which caused the sticking....... I've certainly seen worse than above and could see it sticking from all that crap, but beyond that plenty of other vehicles on the road in cold climates DO NOT have anything keeping the throttle body warm and they don't stick during colder weather.
No, it wasn't.
You guys should go back to LRO. :smilelol: