I don't think this is anything new. My 1985 Suburban has an R12 system. It has an orifice tube located in the engine bay about 8 inches from the exhaust manifold.

TimK

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EPA 609 & 608 HVAC Certified
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83' 300D Turbo - 300K + Miles
00' 1.9L TDI Beetle
85' 6.5L Turbo, GV-OD, GMC Suburban,
67' 2.5L Diesel NA - Land Rover Series IIA

Here's what you do if it's so cold your diesel fuel gels. Smear some on some toast and stay inside until it warms up outside.