EFIDynoTuning Forum

Hello all,

I'm just getting started with tuning my 1998 Mustang GT (NPI 4.6L, 5-speed) and wanted to introduce myself and get some advice from you experienced folks. Currently, I’m using a QuarterHorse with TunerPro RT on a stock FHA3 bin, with emissions and EGR deleted, running in closed loop.

My long-term goal is a full PI swap (intake, cams, heads), and eventually adding a procharger down the road. However, I'm intentionally taking my time, upgrading one or two components at a time so I can really learn and understand exactly how each modification affects the tune.

I’m a former F-16 engine mechanic. About a year and a half ago, I transitioned out of the military and started my own business focused on ADAS calibrations, module programming, and vehicle diagnostics. Troubleshooting complex systems isn’t new to me, but tuning definitely is. My ultimate aim is not just to flash a tune and drive it, but to fully understand the process and eventually create and tweak tunes independently.

Right now, I'm looking for guidance on where best to start. My injectors are pretty rough after an intake manifold replacement (due to an air leak), so new injectors will be coming soon. I'm mindful not to select injectors that are excessive for my current NA setup, yet flexible enough for incremental upgrades, ultimately supporting a procharger or something of the like.

Should I start with injectors, cams, intake, or something else entirely? I'd prefer not to tackle everything at once unless it's essential.
I’d greatly appreciate any insights, advice, or lessons learned from those who've walked this path before. I've spent a good amount of time reading through the forums, and it seems the experiences shared here are invaluable.

What does an air leak have to do with injectors?

No such thing as excessive injectors only not big enough.

Best bet is siemens deka 80 lb injectors from PAS. Siemens is supposed to be releasing a new batch here shortly.

If your doing them in a specific order then injectors, intake then cams would prevent any rework but doesnt really matter.

From your injector notion its obvious you didnt read the pre tune info on the homepage. Best bet is to start there and work your way through the write ups.

When i replaced the cracked intake manifold i found one of my injectors has a crack in the plastic cup that inserts into the manifold. It has nothing to do with the air leak(new manifold fixed that anyways) i just figured i would replace them all. Im just wondering what ones will work with what i have now and support future upgrades so dont have to buy a new set later. From the write-ups (i have read multiple times, they are very helpful btw) there are better ones i can get. I know its not gonna do anything helpful currently but becuase I gotta replace one might as well upgrade them if it wont hurt anything. if upgraded ones dont work with what i have now ill just get a new stock one and upgrade when needed