The only method for reprogramming...
The only method for reprogramming Ford EEC IV processors is through the use of devices that plug into the J3 service port. When such a device is installed, the EEC looks to the programming on the external device and ignores its internal programming. J3 devices are typically chips, such as the ChipMaster Revolution (below left), but they can also be more elaborate devices such as the TwEECer (below right). A big advantage of J3 devices is the ability to load several different tunes, and switch between them on the fly.
In part 1 of this three-part series, we covered the basics of EFI, with an emphasis on the Ford systems, though still with a somewhat generic explanation. Last month we got more into the specifics of tuning the Ford EEC, but we didn't actually get around to custom tuning anything yet. Now that we've covered the theory, we can finally put it to practice.
How? There are many aftermarket systems available for the DIY types for tuning Ford EEC: EEC-Tuner, TwEECer, SCT Pro Racer Advantage, Superchips, Moates F1/F3, and so on. Some systems use add-on chips/modules that plug into the service port of the ECU, some use Flash Programmers that reprogram the actual ECU, and others can do both. For this article, we'll be using a DiabloSport Predator Flash Programmer, and custom tuning using ChipMaster Revolution software. Although the CMR software is available only to dealers (at this writing), the concepts and techniques are the same for the other systems.
We Say, "Go Big Or Go Home."If we're gonna tune, let's tune something worthwhile. So instead of tuning a bone-stock '89 5.0, let's go after an '04 SVT Cobra, first stock, then with added boost and other bolt-ons.
While our subject vehicle ended up only mildly modified, "mildly modified" for an '04 Cobra still means big horsepower and the need for a custom tune. This particular Cobra had just a 2.80-inch pulley, an after-cat exhaust, and a cold-air intake (CAI) added, but that setup is good for well over 500 hp at the flywheel.The extra boost required changes in fuel and spark control, and while the stock MAF sensor and fuel injectors were still used, the added CAI made MAF curve tuning necessary, too. In stock form, we also found more power by working the tune a bit, so custom tuning is a good thing.
For this mild level of modification, the stock Cobra fuel pump and injectors will get the job done, but just barely. Similarly, the stock MAF sensor will not "peg," but we'll be using all of its available dynamic range. Since the stock TB, intake, cams, and displacement were used, idle air tuning was not required (but we did need to tune the MAF curve in the idle range, when the CAI was added).