Jeep Strokers

does anyone know what size stock 97 TJ 4.0L injectors are? i have a 4.7 stroker and i know i need the 24#ers, i'm just curious what stock are? i tried calling my local jeep dealer and they had no idea.

The '97 injectors are rated to 23.3lb/hr at 49psi.

so why is is such a big deal to go to 24#ers? is it really that much of a difference?

You will need larger injectors so you won't run lean @ WOT.

will i need larger then 24# ?

The problem is that you are comparing apples to oranges, though it's completely understandable. The stockers are rated at that at 49psi which is what the regulator should be supplying, the 24# fords etc are rated at 24 at a lower pressure(sorry I don't remember what that rated pressure was, but a search should find it as it was here that I read it), if I remember correctly they work out to about 25.6# injectors when run at 49psi. Another factor is the altitude that you are running it at. I live at 5k ft and my 4.6 seems to run pretty nicely with a set of Neon injectors that only seem to put out 23.5 or so at 49psi fuel preasure

doc65 wrote:The problem is that you are comparing apples to oranges, though it's completely understandable. The stockers are rated at that at 49psi which is what the regulator should be supplying, the 24# fords etc are rated at 24 at a lower pressure(sorry I don't remember what that rated pressure was, but a search should find it as it was here that I read it), if I remember correctly they work out to about 25.6# injectors when run at 49psi. Another factor is the altitude that you are running it at. I live at 5k ft and my 4.6 seems to run pretty nicely with a set of Neon injectors that only seem to put out 23.5 or so at 49psi fuel preasure

I live in denver so i'm at that altitude as well. did you ever have a problem with it bogging out right when you stepped on the gas at idle then it a few seconds later it would scoot pretty good?

I don't have any issue with bogging though admittedly I'm still doing engine break-in and it's in a ZJ with a tired trans, I can break the 1st OR 2nd clutches loose at anytime by pushing the gas moderately. I do have a set of Ford Racing 24# blue top injectors with the 4 holes that I can put back in, but so far when I pulled the plug to look at them a few days ago they look really nice. My throttle body is stock for now, but I have another I pulled from a junk yard that I plan on opening up, I may need the extra fuel from the larger injectors at that point.

ps. My next project on this ZJ is to build a hybrid transmission that'll take what I'm putting out which entails taking the internals from a V8 trans(44RE) and putting them in the L6 trans. case(42RE) while also replacing all the clutches etc and doing a shift kit to firm up the shifts.

doc65 wrote:I don't have any issue with bogging though admittedly I'm still doing engine break-in and it's in a ZJ with a tired trans, I can break the 1st OR 2nd clutches loose at anytime by pushing the gas moderately. I do have a set of Ford Racing 24# blue top injectors with the 4 holes that I can put back in, but so far when I pulled the plug to look at them a few days ago they look really nice. My throttle body is stock for now, but I have another I pulled from a junk yard that I plan on opening up, I may need the extra fuel from the larger injectors at that point.

You cant tell squat by looking at your plugs,unless you shut the engine off at wot under a load,which is were it will be lean,and would show on plugs.looking at the plugs shows how the engine is running at a idle,which isn't where problems usually occur.do yourself a huge favor and add the cost of a wideband o2 to the cost of any stroker.

BDD wrote: You cant tell squat by looking at your plugs,unless you shut the engine off at wot under a load,which is were it will be lean,and would show on plugs.looking at the plugs shows how the engine is running at a idle,which isn't where problems usually occur.do yourself a huge favor and add the cost of a wideband o2 to the cost of any stroker.

x2. You can't tell how the injectors are working unless you do a WOT run and shut it off the very second you let off the pedal. Then pull a plug. And you have to know how to read plugs. Rich or lean isn't determined by looking at the tip.

All true enough, you'll note however that I mentioned that I'm still working on engine break-in, and that due to trans issues I CAN'T do WOT runs anyway, I will install a WB O2 sensor once those issues are resolved

wheelinman88 wrote:I live in denver so i'm at that altitude as well.

You shouldn't need to use smaller injectors just 'cause you're at a higher elevation. The injector duty cycle is determined by the MAP sensor so that automatically compensates for thinner air when you go to higher elevations. If you use smaller injectors and then go down to sea level, your engine will run lean and detonate. Get the correct injector size for your engine and leave it to the MAP sensor to take care of the duty cycle.

Again, completely true, BUT, I had them, they are installed & running well while I break in the engine, and this engine/vehicle will likely live the next several years at this altitude or higher. I wasn't inferring that I NEEDED smaller injectors, but rather that HERE at least I don't NEED larger as I'm not maxing out the duty cycle of the 703 injectors.

Hi all on this great forum,

Don't want to hijack this post but I have a similar question for my 2004 TJ.
I have a 4.7L stroker which runs fine on the stock injectors. I read that the injectors on a 2004 model are not the same as a 1997 model (6EV vs 1EV?).
To get most out of it I plan to change my injectors and am looking at the 24# Ford injectors. I have no idea if this is useful and how much pressure and flow the stock (2004 model) injectors bring.
Any advice for a noob concerning the injectors I should choose? I found an adjustable pressure regulator for sale on another forum, is that a useful thing to buy and adjust fuel pressure?
I live at normal altitude and my stoker is running fine since 3000 miles, no problems with overheating.

Thanks and have a nice day, we have indian summer here in France.