To start a 1984 Towncar with a cold engine, you have to turn the key on and pump the gas pedal. What purpose does pumping the pedal do, set the linkage, set the choke, ?, I'm guessing and curious.

There is a better than even chance you have the 2 barrel Variable Venturi carburetor on that car. Depending on where the car was sold new, they either had that or the throttle body fuel injection. Since you do have to pump the gas, that means the carburetor. Pumping the gas does 2 things. First, it 'sets the choke', which means changing the calibration of the venturi flaps on the top of the carburetor. It also activates the accelerator pump, sending a shot of raw fuel into the intake manifold. If the system is working properly, one pump of the throttle is all it needs unless the temperature is a long ways below freezing. Were it my car, and I planned to keep it long term, the first thing I would do is get rid of that VV carburetor. NOBODY really knows how it works, and nobody really knows how to make it work when it malfunctions. I think voodoo was used at the factory. You can replace it with a normal 2 barrel Motorcraft carburetor from a late 70s Thunderbird, and this takes about 10 minutes. Just set it up right, and your mileage will likely improve. The other option is to upgrade to an Edelbrock Performer 4 bbl intake with either the 1401 carburetor body (made by Weber) or the plug and play Performer sequential fuel injection system. This is a much more involved upgrade, but can return unbelievable fuel economy. If you drive a lot, the upgrade will pay for itself, sometimes in as little as 3 years. That is how significant the fuel savings are. I am looking at buying a 1980 Colony Park with the VV carb, and this is precisely what I plan on doing.

Oh Michael, I can overhaul a VV in my sleep! Ford trained and certified and YES! I do know how a VV works! The sliders react to engine load and demand and move needles that control the flow of fuel through the main jets. They're simple - ask any motorcycle mechanic! You are correct about the upgrade to a 2 barrel paying off in a few years - the diaphragm in a VV only lasts about 2 years and an overhaul is around $300. No Voodoo - just vacuum and variable jets. The hardest part is setting up the choke and that's not very difficult. Don't say No-one. 35 years of experience with Fords, ASE and Ford Master Certified AND I work on a fleet Police Interceptors for a living. (the humor in my VV training was that I learned all about them on a Lazer Disk - remember those big ol' honkin' things? The training system was interactive and I learned all the circuits, adjustments and set up with a light pen.) then I made a bunch of cash flat-rating the things all over the county! :)~

Thank you very much. I believe I have the throttle body. Can you tell me more a lot more about the upgrade. I just had a remote engine start system installed. It will not start the car when the engine is cold because you need to depress the gas pedal once. The remote system installed does not do this, I don't think any do. Do you still need to depress the gas pedal with either one of the upgrades. Does the upgrade give more power. Is it compatible with the computer in the car. What's involved to install it. Can I do it myself or is someone experienced needed. Thanks very much, Bob

Sorry, all of my background is in OEM. I don't have a point of reference for any upgrades. Perhaps Michael knows about such things. I do not.

If you have to depress the throttle to set the choke, you have a carburetor. I would not bother with the car starter, anyway. Working right, you should have heat from the heater in about 2 minutes no matter how cold it is. These engines warm quickly. Tracy: The reason I say that nobody really knows all of the system is my 89 Grand Marquis. It was a 351/Trailer Tow Package car, with the VV. When I bought it back, I put a VV back on it. Finding out, even from Ford Historic Services, any of the specs on it, proved to be impossible. My brother also spend a mint trying to keep the VV system working in his 86 Colony Park. It was less money to switch the intake and carb over to an Edelbrock intake and carb. Tennisshoes: When switching from the VV to the normal 2 bl, there are no brackets or anything else that need be found or made. I did it, in about 15 minutes, when the VV quit on my 89.

I realize that the VV can be a PITA. The down side of changing over to the 2 bbl wasn't the work - you're absolutely right - 15 minutes - done. It was the cost and the loss of CFM. The VV was as capable as a 4bbl in delivering air and fuel - just a big ol' PITA to keep up. Ever hear of a Predator Carburetor? It's a VV but very simple. Too bad they couldn't get it to pass emissions back in the day - awesome square carb that really delivered.

I would sooner put the extra effort in and get the Edelbrock Performer intake with the square bore 600 cfm 1401 carb body made by Weber. It works a treat. As for the loss of CFM between the VV and the normal 2 bbl, there is not enough lost to feel. When I had to remove the VV from my 89, I put on the 2 bbl from my 79 Thunderbird 302. Performance stayed the same, and fuel economy actually increased with the normal carburetor. To me, that entire VV system was a bad joke. Better to have a real carburetor or else go to proper fuel injection.