M/E Wagner Dual Flow PCV Valve aids EFI System Tuning
Words and photos courtesy M/E Wagner
Background: How can a PCV valve influence EFI system tuning success?
As the muscle car, hot rod and collector car aftermarket moves further into the 21st century, technologies that have long been used in OEM applications are increasingly becoming more accessible to enthusiasts. Once considered cost prohibitive and temperamental, Electronic Fuel Injection (EFI) systems are becoming far more commonplace and easier to use for the enthusiast who has limited fuel injection tuning experience.
The accessibility of EFI to a wide range of customers relies on the concept of “self-tuning”, meaning after the user inputs a few key parameters, the EFI system will monitor and refine its own tuning maps as the car is driven. 
Although self-tuning systems are continually becoming more adaptable, they still rely on the engine’s fundamentals to be correct in order to work properly. Vacuum leaks or unmetered airflow to the intake can be especially problematic for EFI tuning cycles, and for this reason an improperly matched Positive Crankcase Ventilation (PCV) valve is a hidden obstacle for many users when trying to implement any EFI system.
At M/E Wagner Performance Products, we have sold thousands of our Dual Flow adjustable PCV valves to enthusiasts all over the world. In recent years, we have solved tuning issues for an increasing number of customers who are suffering from EFI tuning problems due to mismatched PCV valves. Installing our Dual Flow PCV valve has enabled these users to properly and consistently meter the airflow through their PCV systems, ultimately allowing the EFI system to properly tune itself and work as originally intended.
Case Study: Kelly Hattori’s ’66 Mustang
M/E Wagner received the following message from Kelly Hattori after she installed our Dual Flow PCV valve on her ’66 Mustang. Kelly is running a Holley Terminator EFI system, and like so many of our customers, she found out that having a properly tuned PCV system was the final piece of the puzzle to getting her EFI system working as intended.
M/E Wagner,
I’m glad that I could help turn a bunch of people on to the awesome product that you’ve built! It has really helped my car out a lot, way more than expected! I swapped to it initially as I needed to get rid of a fixed orifice valve that was in there, and others on the Vintage Mustang forum said that they really liked the tunability. I did not expect it to significantly affect my EFI idle quality and overall smoothness.
After the install, I did need to adjust my throttle body EFI idle screw down a bit, as it was trying to idle a little high. But beyond that, no other changes needed. Quite honestly, I did not expect to see any measurable change in…well, anything, after the install. My only expectation of it was that next time I was out on the highway running hard, I wouldn’t come home and have oil dripping all over the headers.
Remarkably, though, the PCV valve did improve my drive quality! I’ve always had a bit of an erratic idle surge, and a bit of a stumble here and there on acceleration. It has never bothered me enough to want to get back in the wrestling ring with the software for another round. This new PCV has caused my idle to smooth out almost completely, and driving is much more crisp without the odd occasional stumble.
Thanks again for making such a great product!
Cheers,
Kelly Hattori (mapandamustang.blogspot.com)
For more information about M/E Wagner’s patented Dual Flow PCV technology visit www.mewagner.com
