seschenburg

Recently I saw the idea of swapping stock injectors for a newer style on a web site I don't remember. The idea presented was that the stock injectors in the early 5.0L had a single port that would shoot the fuel in more as a jet than a spray resulting in less atomization of the fuel. Supposedly injectors from late 90's model Explorers, Crown Vic, Tbird, Cougar, and probably others, have four ports that give a misty spray pattern and the theory is that swapping the older for the newer would improve fuel burning and, therefore, efficiency and MPG.

My stock injectors are part F2TE-A3A. These are the orange-top, fat-body, 19 pound style. I see that they have four spray holes so maybe they are not the older style.

While at the local parts yard today I grabbed two sets of injectors:
One set from a 96 Cougar. These are part F4SE-A1B. These are the all-orange, slim-body, 19 pound style with four holes.
One set from a 97 Tbird, 4.6L. These are part F6VE-A5A. These are the all-orange, slim-body, 19 pound style with four holes.

I'm wondering two things....First, in each set of the injectors I obtained I notice that four of a set have a letter designation (A, B, or E) on the body of the injector, and the other four of the same set have a different letter (A, B, or E). All of the other numbers match within each 8 injector set, it's just that four have one letter and the other four in the same set have a different letter. What is the meaning of this letter?

Second, has anyone "upgraded" their injectors with a newer version and what were the results? What are your thoughts/advice/opinions on doing this with my 94 5.0L?

BLDTruth

Don't have the answers to the part numbers, but:

https://www.fullsizebronco.com/forum...r-upgrade.html

TL;DR Probably not going to make much difference unless you have mods that require it.

Steve83

These engines are NOT so sensitive to spray pattern that there would be an appreciable change, unless it ran worse. As long as the replacements have roughly the same resistance as the correct ones, you can't do much damage, so try it if you want, and post your results.

seschenburg

Well, I finally did this and I can say that the newer injectors are a plug-n-play swap. But, whether you will notice a difference is debatable. The thing is that my original injectors had issues (causing hesitation and stumbling) so any improvements I've seen (smoother/quicker response) could just be due to swapping working injectors for my defective ones.

I also "rebuilt" the replacements before installing them...new o-rings and filter, as well as putting a bit of Chevron Injector Cleaner into the fuel rail when I assembled it. Yeah, it smoked pretty good when I started it back up, but not for long.

I still don't have an answer about the letter designator. It probably doesn't mean anything in a practical sense as they seem to be working just fine. I didn't pay attention to this letter when I installed them so they are in randomly, as opposed to putting one letter group on one side and the other on the other side.

Anyway, if you need replacement 19 lb injectors, the newer models will work fine.

Slowbrick

Thanks for taking time to come back and provide an update to this topic.