3.6 Pentastar injector upgrade

All about 3.6 Pentastar injector upgrade: 

With our Jeep JK Rubicon camper engine out for replacement, we figured it'd be a good time to upgrade the injectors. The 3.6 pentastar fuel injector upgrade consisted of these 8-hole injectors from the newer Pentastar 3.6 PUG engine P/N: 05281427AA. They should theoretically improve atomization, and therefore improve fuel economy, reduce misfires, and produce better off-idle tip-in response. Turns out these come with new O-rings too, which is nice.

Another nice thing is how this fuel injector upgrade drops right in place of the stock injectors without any trouble or modification at all, as can be seen below:

Why we went with these for our 3.6 Pentastar injector upgrade.

The decision to run this particular fuel injector upgrade came after reading all we could find about available 3.6 Pentastar injectors on various forums and Facebook groups. As it turns out, those who've installed these are reporting a 0.5-1.5ish MPG gain in a JK and as much as 3 MPG in a Charger. While many opt for aftermarket 8-hole injectors, we bit the bullet and bought these genuine Mopar injectors because we have more trust in Mopar parts and would rather not need to disassemble the intake and fuel system again.

Installing the injectors.

As you know, the injectors drop right in like the originals, but getting to them takes a little bit of disassembly. The job isn't terrible, but you must remove the engine cover, Intake hose with AIT sensor, upper intake manifold with throttle body, and fuel rail. This is all but a few bolts away from the work required to change the lower intake manifold, so we opted to do the PUG lower intake manifold upgrade while it was apart. Adding to the "While I'm in here" work, we also upgraded the oil filter/cooler housing as the plastic units are notorious for failing and causing oil leaks and/or oil/coolant to mix. This trio of mods makes for good peace of mind we won't need to rip it all apart again soon for the dreaded oil cooler leak.

How we like the upgraded injectors so far.

We have now had these installed for a few years and our Jeep runs smoother than it ever had before. The 3.6 now has noticeably better throttle response right off idle too, though that could be partially attributed to the upgraded intake manifold we did at the same time. As for improved MPG, it is hard to say whether the injectors or other mods are responsible, as we also installed an upgraded lower intake manifold, Magnaflow Overland exhaust, and 8-speed automatic. The Jeep is now averaging over 14 MPG despite being over 6,500 lbs and our tendency to do 80+ MPH most of the time. This is as good or better than what it'd do when it was 1500 lbs lighter on smaller 35" tires. If you really want to nerd out on the details, check out the Fuelly log we keep with every fill-up here. Also, check out the upgraded intake manifold and aluminum oil filter housing we added while the Jeep was apart!