Another option could be to use a mass airflow that would pair with the set of upgraded injectors. I havent personally tried doing this and would highly recommend a wideband still if you do but say using the 19lb injectors from a late 90s mustang gt and also that mass air sensor. That might be the easiest and least invasive way to go. Also the 19lb injectors running at the higher pressure the 4.9 uses would probably flow closer to a 24lb injector. I would try this!

 

I don't mean to highjack this thread but since there is quite a bit of mention on here regarding different tuning systems ie SCT, Tweecer, Tuner Studio, etc I wanted to pose a few questions, in search of some direction, as to performance/mpg mods......I have not given much thought thought of installing heavier injectors on my 1996 4.9 (5 speed manual). It has a 2.73 rear end and I intend to keep gearing. It is almost a "time capsule" with 40,500 original mileage. I probably won't install injectors since I am not doing a big bunch of mods in my "Phase 1". If I can get a bit more hp/torque and mpg, there may not be a "Phase 2".

(1) Since my EFI motor already has good enough flowing split exhaust manifolds....I am just opening up the exhaust flow with a catback setup w larger 2 1/2 pipe into a flow thru muffler with a shorter tail pipe exiting just in front of the passenger side rear wheel. (2) Installing some 1.7 Chevy truck rocker arms for a little more lift.
I'm not wasting my money on a cold air intake....I have heard plenty of guys say the factory box is already "cold air" .....especially with using a more free flowing air filter in it. I am also not putting a hotter coil in it. The Ford one is plenty hot I believe. I very likely will put a good set of new plug wires on it w/some new copper plugs. I might play with the timing a bit but that is about all.

With the minimal things I am intending to do, as outlined above, I do think a good tuner will probably help as much as most anything else in my "Phase 1". In addition to feedback on those tuners I mentioned (SCT, Tweecer, Tuner Studio) I am wondering if anybody has any feedback on a system called "ChipYourCar? Thanks very much for any suggestions.

 

No a tuner won't do anything for you with the motor remaining essentially stock, there is more than enough self-adjustment range in the stock "tune" to handle a free flowing exhaust. The single best thing you could do for better performance would be better gearing in the axle, depending where you are and how you use the truck this could also result in improved milage too.

 

Regearing would give you a decent jump in mpg...but since you stated you arent willing to do that, just leave it in 4th at highway speed. It will simulate a gear swap. Similar to putting a 3.55 gear in your truck. Which is what my truck has from the factory. Drive it like that for a tank and see what the mpg is. As for power... it is the i6 short of more compression and a cam or turbo the factory stock engine a gear swap is your best bet.

 

I had been told that since I have the '96 EFI w/ MAF, I wouldn't be able to do things like rework/cleanup the head and/or a cam., etc...without messing up the ECU, etc....and creating more problems than I would solve? I see so much contradictory advice on these forums I stay pretty confused. I chose the I6 cause I like unconventional engines and the idea of doing some things to them for perf/mpg improvements, but now I'm being told to leave well enough alone unless you want more headaches.

 

If you want to get into modifying *any* of the Ford EEC-IV (I don't actually know, are the MAF OBS trucks still EEC-IV? I know they're still not going to work with things wildly different than stock) equipped engines, you're going to have to get into some sort of tuning. The Stock Computer just isn't meant to deal with much beyond what it was designed for. Whether that comes through something like an ECU replacement, like a PiMPx or Megasquirt, or a piggyback tuner, like at TwEECer or Quarterhorse, if you want to do any sort of serious engine work, or forced induction this is just how it is. The Six Cylinder vs Eight Cylinder hasn't a thing to do with it.

 

Thanks so much for your thoughtful reply. Guess I'll just drive it like it is. Or...maybe just do a little bit and then go let a dyno shop put a tune on it. Me trying to understand how those self tuning systems function is just not something I want to fool with myself.