99+ Intake Manifold Modifications

[Michaelarchangelo]

It is a screw in. What you can do is pick up another one from a junkyard, relocate that one to your intake tube, and leave the broken one in the manifold to seal up the hole (or you can buy a new one).

 

[BBeach]

Whats the one in the middle? Right next to the bottom right corner of the throttle body mount. I looked inside the runners and they seem pretty smooth, minus all the gunk that I'll clean up. Once i get to school I'll sandblast it and then clean it out to make sure i dont have anything left in it.

 

[Flash]

just guessing here but it looks like the larges port on the manifold.......for the vac brake booster?

Flash.

 

[seanyb505]

It goes to the back of the rocker cover...
http://www.go.jeep-xj.info/HowtoIntakeManifold2.htm
You can kinda see where it goes in some of the pictures. I have a 97 and this fitting required some resizing to fit properly when I switched to the 99 intake.

 

[CartsXJ]

19# injectors

it's a '97.

Find a set from a 98 XJ, they are 23.8# injectors. You actually drop injector size when you went to those 19# ford injectors. 96-98 XJ's came with the 23.8#, 91-95 came with 18# I think and then 99-01 came with 21-22# injectors. Jeep was funny like that. I do know that even though they list the same injector at Napa and autozone, they are different animals depending on the year.

 

[goodburbon]

Can anyone else confirm this? I don't really care, it's only 20 minutes to change a set of injectors out, and I have a few sets lying around. one from a 97 , one from a 99 and the set of ford orangeish yellowish
injectors.

 

[CartsXJ]

Can anyone else confirm this? I don't really care, it's only 20 minutes to change a set of injectors out, and I have a few sets lying around. one from a 97 , one from a 99 and the set of ford orangeish yellowish
injectors.

This is from Dr. Dyno's site:


Quote:
The following is a list of the injectors used on the 4.0L since 1987 along with their rated static flow:

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

The injector flow rate varies as the square root of the pressure drop across the injector. The stock '91-'95 4.0 injectors are rated at 22lb/hr @ 43psi fuel pressure, so at 39psi they flow ( sq. rt.(39/43) x 22.0 = 21.0 ).
For stock/modified 4.0 engines or stroker build-ups the following injectors can be installed. The flow rates are:

Ford Motorsport 19.0lb/hr @ 39psi (Part no. FMS-M9593-C302)
Ford Motorsport 24.0lb/hr @ 39psi (Part no. FMS-M9593-A302)
Ford Motorsport 30.0lb/hr @ 39psi (Part no. FMS-M9593-B302)
Chevy LT1 24.0lb/hr @ 43.5psi (Part no. 17124248)
Chevy LT4 28.0lb/hr @ 43.5psi (Part no. 17124251)
Accel 19.2lb/hr @ 44.1psi (ACC-150119)
Accel 21.1lb/hr @ 44.1psi (ACC-150121)
Accel 24.4lb/hr @ 44.1psi (ACC-150124)
Accel 25.6lb/hr @ 44.1psi (ACC-150126)
Accel 29.4lb/hr @ 44.1psi (ACC-150130)

The '95 Jeep 5.2 ZJ/Dodge 5.9 injectors (Part no. 53030262) are rated to flow 24.6lb/hr at 39psi



So I was off by a little on the decimals

 

[JTwthaXJ]

I know that this is a little off topic, but I bought new 19# injectors from five-0 motorsports a while back. I was told that these were right for my '97. My gas milage had been a little off for a while because I had been having an issue with the injector on the first cylinder, but my mileage is still down from what it used to be (way down.) Could the lack of fuel actually cause this probelm? I know that if the 23.2# is right then all cylinders are running lean, way too lean, lean=heat=$$$.... help please

 

[goodburbon]

I was told that these were right for my '97. My gas milage had been a little off for a while because I had been having an issue with the injector on the first cylinder, but my mileage is still down from what it used to be (way down.) Could the lack of fuel actually cause this probelm? I know that if the 23.2# is right then all cylinders are running lean, way too lean, lean=heat=$$$.... help please

x2 WTF! I thought we were supposed to use the 19# injectors until we increased displacement, and then were to step up to the 24# units.

:banghead: