So, I have read a bunch on here about injectors for the 4.0L engines. From pressure changes, to flow rate changes, to spray pattern changes, there are all kinds of options.

My specs -
1997 4.0L Cherokee, AW4. I am currently running the OEM Bosch injectors in this jeep. I am getting ready to free up the exhaust and install a 99+ intake (here's to hoping for power! ) I also plan to bore the TB and install a cowl induction intake with a canister cold air.

My questions:

1. I have been told a bunch of different things about the J-tech controller ECM in this jeep. Is it adaptive or not? Will resetting it really allow it to reevaluate the sensors? Will it adapt to new injectors?

2. What value are we really seeking to change to make more power? I have increased the available air, it only makes sense to make more fuel available.

3. What injectors are an "upgrade" to the 97 4.0? I have a set of Bosch/ford 280150556 (FOTE 05B). Will these be an upgrade? I see 4 holes in the bottom, so I assume at least a better spray. They are from a 2000 F 150 with a 4.6l (??) I can't find specs on them anywhere.

 

Check out this thread:
https://www.cherokeeforum.com/f2/mor...-13848/index3/

My interpretation is that the 4 hole injectors from a 4 cylinder Chrysler product like the Neon would be the easiest way to go. I might give those a try if I can score some from a JY.

 

I have read that thread many times. Thanks for pointing it out though. Neon injectors are not drop it though right? Different plugs.

80's chrysler turbo injectors will fit, here is info on them. but I'm not sure if any of these would work.

http://www.thedodgegarage.com/turbo_fuel.html

Found this data..
Model Year, ...Part #, ......Colour, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, ...Dark Tan, ...39psi, .................18.6lb/hr
'91-'93, ........33007127, ...Brown, .......39psi, .................21.0lb/hr
'94-'95, ........53030343, ...Tan, ...........39psi, .................21.0lb/hr
'96-'99, ........53030778, ...Grey, .........49psi, .................23.2lb/hr
'99-'01, ........04854181, ...Blue tip, .....49psi, .................22.5lb/hr

 

Looks like stock turbo 1 injectors will have a higher pph at 49 psi then my stock 23lb/hr would, they have 27lb/hr at 55psi...hmmm I'm pretty sure I have 6 of the 33lb/hr at 55psi laying around (Turbo II)

 

i've heard 5.0L mustang injectors work, but i have no experience with them.

 

ok? See this is my problem Internet! What engine did you hear it would work on? What year 5.0? Blanket statement is weak.

 

I had to replace my leaking stock '87-'90 bendix injectors and my options were the following:

*BMW bosch injectors 16 lb, four holes worked very well, smooth idle but no power gain
*Siemens '96-'99 grey cherokee injectors, one hole, just a little too rich at idle but more power
*Corvette injectors ('95 LS1), one big hole, 28lb, too rich, bad at idle, crazy at WOT.

Then i found this:
http://www.angelfire.com/my/fan/MAP_adjuster.html

I fabbed it and could finally regulate the pulse width how i wanted.
I put back the grey cherokee injectors and reduced the voltage a bit, tuned the air fuel mix reading the O2 sensor output with my tester and voila! Smooth idle, and power/torque gain.

 

Found a spec for these ford injectors.
20 lb/hr at 43.5psi. So at 49psi they will still flow less then my stock injectors do correct? 23.5lbs/hr at 49


http://users.erols.com/srweiss/tableifc.htm

 

All injectors on the 5.0 are the same unless you step up to the cobra engine. Even then, the fitment is the same, they're just higher pressure. Use year models 90 - 94 mustang and you'll get the right part. I believe they will bolt in 91-99 XJs. I'll see if I can find more info.

Here's a good thread on fitment for various parts.

http://www.jeepforum.com/forum/f11/b...fit-xj-847303/

 

^yup, what he said, only i heard they work on all jeep 4.0L, including the renix.

 

They fit also on '87 to '92.

 

Well if you do a linear proportion you would have:

20lb/hr at 43psi : X at 49psi

X = (20x49)/43 = 22.8lb/h
that is slightly less than 23.5lb of your stock injectors

 

so what injectors should you go with