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Can't start in the morning: Ford variable venturi carburetor

Whenever it’s cold, my elegant police-package 5.8-liter 1991 Crown Victoria will not start. I’ve narrowed this down to what I think is called the “cold enrichment system,” but I can’t find out anything about it! This carbureator (i think the model is a motorcraft 7200) has no choke; in its place is the so-called variable venturi. Thus it “chokes” the car with whatever “system” if it’s cold – and i don’t know where to look to diagnose or replace it. So i’m using a ketchup bottle to let gas trickle into the carburetor while the car warms up. Once it’s been running a minute, the life-support-giving bottle comes out and the car runs 100% fine. Well, except for the fact that overdrive no longer works…

The cold enrichment adjustment can be found here.


My father-in-law had one of those infamous VV “feedback” carburetors in his Mercury Grand Marquis. He ended up getting a retrofit regular carb on it. I don’t know if you can still buy those. It soved the problem for him.

Holy cow, that’s informative! I did forget to mention one thing – that the car sat from about 2009 to 2012. All right – so it takes me a while to change a bad water pump! But until 2009, the car started when cold just fine. Suddenly, it doesn’t. You can crank and crank and it’ll never start, until you squirt gasoline into the carb. Point being: The working-fine-one-year-and-not-at-all-the-next suggests to my mind that there isn’t anything to adjust. (Maybe something’s stuck, so it’s still worth a try.) But seeing the PDF, I’ve really got my eyes on Part No. 45, the cranking-enrichment solenoid. When something completely fails, electrical failure of a part like that sure would seem likely … Gonna get to it! Thanks for this incredible instruction sheet. Exactly what I needed!

There may gunk in the carburator from sitting too long. Add a can of Seafoam to the gas and drive the vehicle to see if it has any effect.


It’s time to bring everybody back for Stump the Chumps. There IS no cold-enrichment solenoid (1979 only, I think I saw somewhere) and there’s no need for Seafoam. Thanks to Tester’s diagram, I was able to hunt down the rods that actually choke the thing in the morning, based on how cold the bimetallic coil is. Guess what! The rod had been stuck in place and after one second of jiggling, came loose and right back into full operation. Car has started cold every morning for the last three mornings! THANKS FOR THE DIAGRAM! Couldn’t have gone after the problem without it.

There is a guy on another thread with a 7200 on a '83 Ford F-150…That carb NEVER worked right…Replace it with one made in 1979 or earlier…Or, even better, step up, WAY UP to a 2005 or newer P-71 model Crown Vic.Leave carburetors to the history buffs…