Topic: old subject

[damon54]

I read the posts about the Ford 19 lbs fuel injectors and plan on getting some for the YJ after the engine rebuild.  I also have a 4.0 in my cherokee.  Has anyone tried the injector swap on the 6 cylinder?

[JeepManMarc]

Someone fill me in as to why an injector swap is needed on these engines, I was into turbo imports for a long time and understand the need for fuel mods to even out A/F mixtures, but in this case I just dont understand..  The stock computer is only going to allow so much fuel no matter how large the injector anyway.  Just curious if there was somthing I was missing here.

Sorry to hijack your post  :oops: Im just curious...

[tommygp]

The injectors have 4 holes instead of a single hole, so the pattern is better.  The atomization is better with the 19lb injectors.  All I can tell you is that I did notice a difference when compared with my OEM injectors, but some of that could be due to having 100k miles on them.

[StvDiego]

I ran them in my old '88 XJ 4.0 and they did make a noticeable difference, but, my mileage did suffer a bit, although that may have been more from the right foot enjoying the extra bit of power than from the injectors. I got mine out of an old Crown Vic Interceptor at the wrecking yard, put new O rings on and they popped right in. For the effort, I think it was worth it. Don't know if the would fit the newer 4.0's tho, interesting to know if they fit my '98 TJ with a 4.0, or for that matter, the little '01 2.5 squirrel cage

[Jeffy]

I ran them in my old '88 XJ 4.0 and they did make a noticeable difference, but, my mileage did suffer a bit, although that may have been more from the right foot enjoying the extra bit of power than from the injectors. I got mine out of an old Crown Vic Interceptor at the wrecking yard, put new O rings on and they popped right in. For the effort, I think it was worth it. Don't know if the would fit the newer 4.0's tho, interesting to know if they fit my '98 TJ with a 4.0, or for that matter, the little '01 2.5 squirrel cage

Hmm, you put them on a Renix 4.0L.  The injectors were meant to be swapped into a MPFI 2.5L and/or High-Output 4.0L.  I'm not sure what a Renix uses but the +1990 use the Denso 17# single port injector.  I think the 2.5L's use a lower psi then the 4.0L's although I haven't seen anything that confirms this.