So i have a 1994 jeep grand Cherokee se 4.0l and i was really thinking about upgrading to a 62mm bbk throttle body but i was wondering if i should upgrade my injectors as well? Does anybody have any recommendations? im on a tight budget so is there any affordable upgrades? if i have to upgrade injectors will i also have to get a better fuel pump? help me out!

 

I'm copying this from someone else's post on another forum (I don't know if it is against policy to name competing forums.)

Stock Model numbers & Pressures:
Stock 4.0 Injector (93-95): Siemens 53030343; 22.4lb/hr @ 39psi

Injector Recommendations:
93-95 4.0 Bosch 0280155703; 21.8lb/hr @ 39psi (these have 4 spray holes vs. 2 on stock, or maybe 1 on the early years)

I bought a set of 703's from "831xj" on this site. I haven't installed them yet because a dying problem began before I got them and I would like to get that eliminated first.

If you want to flow more fuel, you'll need to use the "swap" injectors from a Ford or aftermarket injectors, OR you could increase fuel pressure by changing to a later model regulator which gives 49psi, if your pump will put out that much. The Ford vehicle injectors are Bosch 0280155710 and Bosch 0280155715, but in that other thread there is debate about the flow rates. They are listed as less, but several people report greater flow and the 710's are confirmed as a suitable swap for a 5.2 V8. The 1999-2001 (at least) GC's, and other Jeeps, have an in-line mounted, return-type regulator for 49psi. The original p/n was 52100281AD (or maybe 52100231AD) but now the Mopar part is 6_________. I had found it earlier.

 

Thanks man really appreciate it! What ford's have the bigger injectors

 

710's in:
1994-97 Mercury Cougar 4.6L V8
98 Ford Crown Victoria/Mercury Grand Marquis/ 4.6L V8
97-99 Ford E-350 6.8L 10-cyl
96-98 Ford Explorer 5.0L V8
99 Ford F-250-550 6.8L 10-cyl
97-98 Mercury Mountaineer 5.0L V8
94-97 Ford Thunderbird 4.6L V8
94-98 Lincoln Town Car 4.6L V8

I can't find the list for 715's right now.