When it comes to engine swaps with late-model engines, one of the biggest hurdles is figuring out a reliable (and hopefully headache-free) electronic fuel injection (EFI) system. That’s where Edelbrock’s Pro Flo 4+ EFI System comes in – it’s a plug-and-play solution that makes things way simpler, especially if you’re working with a late-model engine from one of the big three manufacturers like a Mopar Gen III HEMI, Gen III and IV LS, or Ford Coyote engines.

Following the dyno test of a COMP Stage 2 HRT camshaft in a 392ci HEMI, we got hands-on and installed a Pro Flo 4+ in our 1989 Dodge D150 to give the 6.4L Gen III HEMI a proper home. To understand the Pro Flo 4+, we chatted with Mark Honsowetz,  Edelbrock’s Electronics Department Manager. His insights, combined with our hands-on experience, made it clear why this EFI system is a solid choice for your next EFI-based engine swap.

At its heart, the Pro Flo 4+ is all about keeping things simple, while still delivering top-notch performance. It doesn’t have all the extra baggage of factory ECUs. Instead, it focuses on what matters. It fully supports Gen III HEMIsetups including variable cam timing (VCT), drive-by-wire (DBW) throttle bodies, and short runner valve (SRV) actuation.

Mark told us that the Edelbrock team designed the Pro Flo 4+ to work seamlessly with factory sensors and hardware, so you don’t have to mess with a lot of modifications or custom tuning. “It’s truly plug-and-play,” Mark explained. “You just open the box, hook up the clearly labeled harnesses, and the system is good to go with most factory components. The calibration is already done, so you don’t need to spend hours tuning. You can have a running vehicle in no time.”

The plug-and-play design saves you serious time and money, whether you’re a pro or just a DIY enthusiast. The Pro Flo 4+ kit for the Gen III HEMI comes with a Pro Flo 4+ ECU, chassis and engine harnesses, a Bosch LSU 4.9 wideband O2 sensor, a calibration tablet, and a fuel pressure sensor. Every component is laid out for easy installation, with fully labeled and fused harnesses that ensure a clean, reliable setup. If you need a knock sensor, Edelbrock offers an optional Mopar Gen III HEMI Knock Sensor Harness (P/N 36175).

We started our project by swapping the 6.4L HEMI into our 1989 Dodge D150. The Pro Flo 4+ turned what could have been a messy wiring and tuning job into a breeze. The clearly labeled harnesses made things easy and worked perfectly with the factory sensors, like the throttle body, ignition coils, knock sensors, crankshaft, camshaft, and air intake temperature sensors.

“Our goal was to strip away the unnecessary parts of a factory ECU and give builders what they need – core functionality and seamless integration,” Mark explained. For our D150, that meant plugging in the factory sensors with ease. There were no surprises, no hidden steps, and no custom wiring required.

One of the few tweaks we had to make was installing the wideband O2 sensor, which meant welding a bung into the exhaust system. The included extension harness made it easy to position the sensor, and its role in closed-loop corrections ensures the engine runs optimally.

Once the hardware was all set, we turned to the calibration process using the Edelbrock E-Tuner 4+ App. Mark called the setup “painfully simple,” and he wasn’t exaggerating.

E-Tuner 4+ App

 

According to Edelbrock, the key to its “user-friendly system is Edelbrock’s exclusive E-Tuner 4 calibration app with base calibrations that have been extensively developed for each specific application. However, the closed loop self-learning capability will continually maximize the fuel map for your specific engine configuration as you drive.

 

“Edelbrock’s E-Tuner 4 app utilizes a Bluetooth wireless connection to communicate with the ECU, giving you the ability to monitor engine vitals and performance in real time from inside or outside of the vehicle. The Setup Wizard guides you through the initial calibration procedure with ease. The Pro-Flo 4 then provides the capability to adjust fuel mixture, ignition curve, air/fuel ratios, idle speed, acceleration fuel, coolant fans, rev limiter and much more from the E-Tuner 4 app, giving you complete control of the system. The E-Tuner 4 App is available to download for Android and Apple iOS powered devices.”

The app’s wizard walked us through selecting the right parameters for our HEMI, like engine type, throttle pedal configuration, and throttle body type. Within minutes, the app had loaded the perfect calibration for our setup. “You don’t need to tune the throttle body or guess at settings,” Mark assured us. “The app handles all that.”

For those who want more control, the app also has options like adjusting idle speed, controlling the cooling fans, and monitoring engine parameters in real time. The built-in diagnostic tools make it easy to troubleshoot by clearly highlighting any issues. Mark stressed how Edelbrock simplified the complex calibration tables you usually find in laptop-based tuning. “We’ve streamlined it down to safe, user-friendly adjustments. You’d have to try to mess things up,” he said. This is a huge benefit for less experienced users, making the system accessible to a much broader range of people.

Once it was all installed, the Pro Flo 4+ delivered a flawless performance. The ECU’s advanced closed-loop system adjusted the fueling on the fly, keeping the engine running silky smooth no matter what. The variable cam timing and short runner valve actuation worked perfectly, maximizing both low-end torque and high-RPM power. These features let us get the most out of the 6.4L HEMI without needing a ton of extra tuning or mods.

The 1989 Dodge D150 now drives like it was born with modern tech and classic style. Firing up the engine is as simple as turning the key, with no stuttering or sputtering. Even with the wild temperature swings we’ve had recently, the Pro Flo 4+ kept the engine running like a top.

Getting behind the wheel of the D150 has been an eye-opener. The throttle response is crisp and consistent, without any of the dead spots or hesitation you can get with poorly tuned EFI systems. The built-in variable cam timing control lets the HEMI pull hard through the rev range, and the SRV system ensures silky smooth transitions as the intake plenum adapts to engine speed and load. As Mark put it, “You get OEM-level performance, but without the hassle.” We couldn’t agree more. This is how modern EFI is done right.

What gets us excited about the Pro Flo 4+ is how versatile it is. Sure, we focused on the Gen III HEMI, but this system also works with other popular engine swaps, like Gen III and IV LS engines and Ford Coyote engines. Every kit comes with the same top-tier components and app-based tuning, making it a solid choice for a huge range of builds. Mark emphasized how Edelbrock wanted to make the whole process fun and accessible. “It’s all about keeping it simple,” he said. “We want people to spend less time troubleshooting and more time enjoying the drive.”

So, is the Pro Flo 4+ worth it? Absolutely. By cutting out the complexity of factory ECUs and offering a streamlined, user-friendly alternative, Edelbrock has created a system that lets builders focus on their projects, not the wiring and tuning headaches that usually come with engine swaps. Whether you’re a veteran gearhead or tackling your first swap, the Pro Flo 4+ delivers on its promise of simplicity and reliability.

A small package that packs a big punch.

Edelbrock’s Pro Flo 4+ EFI system is a total game-changer for the engine swap community. It cuts out the complexity of factory ECUs and offers a streamlined, user-friendly alternative that doesn’t sacrifice performance. For our 1989 Dodge D150, the Pro Flo 4+ brought the 6.4L HEMI to life, proving that modern EFI doesn’t have to be overwhelming. As Mark Honsowetz said, “It’s all about making the process enjoyable and accessible for everyone.” If you’re planning a swap and want to spend your time driving, not troubleshooting, the Edelbrock Pro Flo 4+ is a great option. It’s modern tech made simple – just the way it should be.