Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Lololololollol back when my truck was TBI an inspector actually made me walk across the street to a parts store and put the tube on before he would give me a sticker. It hadnt had a tube for 20 years.
The heated air intake has NOTHING to do with choke function. That's not how choke coils were heated.I'm really surprised they kept that on as it's more for carbureted engines that need warm air to open the choke quicker. I removed mine completely when i installed a CAI. Truck runs no different without it.
Of course it serves a practical purpose. When working as intended, it absolutely prevents throttle-body icing in high-humidity, cool weather. Throttle icing is particularly obnoxious at about 40--45 degrees if there's high relative humidity.it really doesn't serve any practical purpose
Air was pumped into the exhaust so that the fiery-hot gasses would continue to burn, dramatically reducing HC and CO emissions. In fact, many engines were run deliberately too-rich, which lowered combustion temperature to reduce NOx emissions, and then the AIR pump would support additional combustion of the HC and CO in the exhaust manifold. The extreme example of this was the Mazda Rotary, which had a "Thermal Reactor" (i.e., a bigass insulated iron exhaust manifold with huge interior volume) where the exhaust continued to burn due to the added air. The Thermal Reactor was still used in 80 or 81, but was replaced with a catalytic converter after that.(Like the AIR pump of the 80s... exhaust had to have a certain level of oxygen so they just pumped fresh air into the exhaust without doing anything else to the engine).
Of course it serves a practical purpose. When working as intended, it absolutely prevents throttle-body icing in high-humidity, cool weather. Throttle icing is particularly obnoxious at about 40--45 degrees if there's high relative humidity.
The heat stove/snorkel deal is intended to keep the air cleaner fed with air at about 100--120 degrees, somewhat depending on year and model. The snorkel will open or close to maintain that approximate temperature.
Back when they were vacuum-operated, folks would disconnect them in the summer, then re-connect the vacuum hose for fall/winter/spring.
A secondary benefit to the heated air intake is that they help a bit with fuel vaporization, along with preventing throttle icing.
Air was pumped into the exhaust so that the fiery-hot gasses would continue to burn, dramatically reducing HC and CO emissions. In fact, many engines were run deliberately too-rich, which lowered combustion temperature to reduce NOx emissions, and then the AIR pump would support additional combustion of the HC and CO in the exhaust manifold. The extreme example of this was the Mazda Rotary, which had a "Thermal Reactor" (i.e., a bigass insulated iron exhaust manifold with huge interior volume) where the exhaust continued to burn due to the added air. The Thermal Reactor was still used in 80 or 81, but was replaced with a catalytic converter after that.