EFI TROUBLESHOOTING/TUNING TIPS

Bob Dylan once wrote “… the times they are a-changin’.” He probably didn’t have electronic fuel injection in mind when he wrote those words, but it is certainly true that there’s been a rich mixture of changes with aftermarket electronic fuel injection in the last 10 to 15 years. It wasn’t all that long ago that most car guys steered clear of electronic control over fuel and spark but with a tremendous variety of high-quality systems on the market and the opportunities they offer have made believers out of at least a few serious doubters.

But we have to admit that this conversion to electronic control has not been easy. There has also been a smattering of challenges to make these systems operate smoothly. It doesn’t take much effort to find negative comments about every system out there. While it’s easy to blame the manufacturers, our experience with many of these systems is that there are often simple solutions to many of these difficulties. We’re not going to blow smoke in your face and claim that all these systems work flawlessly. That’s just not true.

However, we will stand firm on the belief that many of these systems will operate well and offer respectable returns on the investment as long as certain rules are followed and an effort to undo these difficulties is attempted. In our experience, it’s often simple installation errors or an occasional failed sensor that is to blame. But if you follow the instructions—yes you must read the instructions carefully—likely you can avoid many of the pitfalls that plague those installers who just don’t make the effort to do the job correctly.

One point that must be highlighted is that fuel injection is not a cure-all for an ailing engine. If the engine is not running properly with a carburetor, this could be an indication of either internal engine problems or ignition issues that will not be solved by adding EFI.

As an example, we’ve experienced an off-idle hesitation in a small-block, four-speed Chevelle