Then again, the other aspects of an automotive electrical system-battery power and grounds-are also crucial. Abercrombie warned us about dragging starters and poor grounds. "All the power and ground leads on an older vehicle need to be pulled apart, cleaned, checked, and replaced if necessary. It's a big problem with all fuel injection." And lest you think your Chevy doesn't fall into the "old" category, he related a short tale: "We had probs with a '94 MPFI car; well, those are 15 years old now, and the ground strap was split.
"The system needs between 13.8 and 14.2 volts to run properly," he continued. "When going down the road, every little bit below 12.5 volts gives incorrect info to the sensors, creating a bad return path." In other words, you don't reap the benefits of running in closed-loop mode, which is part of the reason for installing an EFI system, since this is where the computer runs the motor at peak efficiency. "Below 11 volts," Aber-crombie concluded, "it's gonna run stinko."
Although we won't be showing you this ordeal, we can testify that Abercrombie's advice is right on, since we had all three of these problems with our subject Biscayne. We replaced a sorely inadequate positive battery cable just to get the starter cranking as it should, made a trip to the local parts house for a new alternator, and went on an extensive ground strap R&R hunt. Save yourself some aggravation and address these issues before you start installing an EFI system. And one last tip from Abercrombie: "Any engine that's in a bad state of repair...it's not the way to go."
Dialing It In
Each Pro-Flo comes with an individualized chip in its ECM loaded with dedicated fuel and spark curves for a specific application. In this case, our 502 crate motor had been fitted with a smaller-than-stock cam: .510 lift, 212/218 duration, 114 lobe separation. Edelbrock sent along a PN 3552 chip, usually intended for 454ci ig-blocks. If you use one of Edelbrock's recommended cams, getting the chip is easy. Getting the proper chip is the first critical step in punching up a slick-running EFI motor.
The advantage of the Pro-Flo system is the handheld calibration module, which allows the owner to customize the fuel and spark maps as needed-if the chip is close, the calibration module is the road to spot on. We won't go through the exten-sive Edelbrock instruction manual for you; instead, we'll summarize Abercrombie's quick course in tuning the Pro-Flo in the accompanying sidebar. With that, we'll let the Biscuit's owner have the last word: "It takes a little to get [the Pro-Flo] dialed in, but the car is now very responsive. It idles comfortably, doesn't surge, and has great midrange. The throttle response is great." Check out the details of how we got there-and got 390 hp and 530 lb-ft at the wheels, even with the tiny bump-stick.
The Pro-Flo system, like just about all electronic EFI systems, requires the use of an O2 sensor. Edelbrock includes the necessary bung along with the O2 sensor; luckily, the headers on our subject Biscuit already had one in place. | 
Before installation, the ECM that runs the system must be opened up and equipped with the chip Edelbrock sends for each particular application (arrow). Our setup took an off-the-shelf 454 chip. | 
Edelbrock includes a high-pressure fuel pump as well as a regulator, hoses, and a wiring harness with each Pro-Flo kit. This Biscayne was already equipped with a suitable setup, so we won't be covering that here. |