Bone Dry

My toy is a 1970 Challenger that was originally a 318 car. It now features a 440 with a four-speed manual transmission. This has been my dream car for years, and I love driving it as much as I did building it. Even though the car is not an original R/T, I wanted to keep it looking relatively stock. I built the engine with a dual-plane Weiand intake manifold that resembles the OEM intake, and topped it with a 800 AVS Edelbrock carb and a factory air cleaner. The car has the stock HP exhaust manifolds, and factory valve covers, so it looks original when you pop the hood.

The problem I have is that the car is very hard to start after sitting. Sometimes, especially in the summer after a good drive, it can be hard to start. I hate going for ice cream with the kids and then having to crank the engine over and over to fire this beast. On the other hand, when I put it up, even for less than a week I'm grinding the starter forever and pumping the gas pedal until she is lit. I have suspected a fuel problem, even though the gas tank, fuel lines and fuel pump were all brand new when the car was built. I confirmed this by taking carb apart after it was sitting for just five days and found there was zero fuel in the bowls! I don't remember any of my old Mopars from back in the day having this problem. What do you recommend as a fix?

Brian Sampson
Via email

Brian, I believe the problem has a lot to do with the fuel formulation of pump gasoline being sold these days. With an EFI system under constant pressure, there is no place for the fuel to go, and the pump delivers instant pressure, so newer cars don't have the same problems. A carbureted car runs with the fuel in the carb at atmospheric pressure, and the carb is usually directly vented. Basically the gas will just evaporate right out of the carb and you are left dry. A small kicker electric pump at the rear of the car near the tank is the real fix, since it will send fuel into the carb before you start to crank.

As for the hard hot starting, the problem is related, with the same issues of fuel formulation and only atmospheric pressure in the carb bowls, but adding the heat from your 440. I've actually pulled the air horn on an AVS while on the chassis dyno to change jets, and could see the fuel boiling in the bowls. About all you can do here is try to keep the carb cool with an insulating spacer, a blocked exhaust crossover, and a return system in the fuel line as originally used in many 440 and Hemi cars.


Which EFI?

I have a 1970 Charger with a 440 engine. The engine was built with the usual aftermarket performance parts, including a Comp hydraulic lifter XE274 cam, 10.0:1 compression, Edelbrock heads, an RPM intake manifold, and a Holley 770 carb. The engine has Hooker header and a 3-inch X-pipe exhaust system. I want to go further with the engine, and I am now thinking about adding an aftermarket fuel injection system. I read about the FAST EZ-EFI throttle body injection system. This set up looks like a simple upgrade, with the throttle body just replacing the current Holley carb. It seems like the tuning is going to be pretty easy with the FAST self-learning programming. The question I have is whether I should go with a throttle body injection or just run a full on port system. What are the advantages and disadvantages of the throttle body injection compared to the port injection?

Steve Green
Via moparmuscle.com

Steve, the port system is more sophisticated and offers more accurate distribution because the injectors are at each port. The throttle body, on the other hand is easier to install and cheaper. FAST has EFI systems in both configurations, with numerous options based upon your budget and needs. Their tech line at 877/334-8355 might be the best place to narrow down what your goals are and the best product to get there. The throttle body will be less complex, easier to install, and more cost effective.