• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Question about 99-01 intake swap and heat soak

M

mrtosh

NAXJA Forum User
Location
Woodbury, MN
I have a '98 that I'm wanting to do the 99-01 intake mani swap on and was wondering if I would ever run into the issues that the 00-01's ran into w/the heat soak on the cyl 3 injector? Anybody who has done the swap please chime in...
Also the manifold I purchased came w/the injectors off a 2000 and the TB as well. I've heard that the '98 injectors actually flow better, any truth to that? Is the TB any bigger/different than the '98?

TIA guys!!
 
The heat soak might be worse on the 2000+s that have precats. The 96-99 injectors flow 23.2# and the 2000+ are 22.5#(iirc). You'll see that those injectors won't plug into your 98 harness.
 
Hmm. I forgot about the Cylinder #3 issue. I've had my '99 intake on now for about four months and haven't had any problems. I've got an unknown brand exhaust header, and am running the same F5TE-24lb injectors from Fiveomotorsport.com that I've had for the last four years.

87-90 Dark Tan 39psi 18.6lb/hr
91-93 Brown 39psi 21.0lb/hr
94-95 Tan 39psi 21.0lb/hr
96-99 Grey 49psi 23.2lb/hr
99-01 Blue tip 49psi 22.5lb/hr

I don't know of any changes to the throttle body.

Jim www.yuccaman.com
 
gradon said:
The heat soak might be worse on the 2000+s that have precats. The 96-99 injectors flow 23.2# and the 2000+ are 22.5#(iirc). You'll see that those injectors won't plug into your 98 harness.
Click to expand...
Precats? Is this something that I would have to worry about w/this manifold?
 
Yucca-Man said:
Hmm. I forgot about the Cylinder #3 issue. I've had my '99 intake on now for about four months and haven't had any problems. I've got an unknown brand exhaust header, and am running the same F5TE-24lb injectors from Fiveomotorsport.com that I've had for the last four years.

87-90 Dark Tan 39psi 18.6lb/hr
91-93 Brown 39psi 21.0lb/hr
94-95 Tan 39psi 21.0lb/hr
96-99 Grey 49psi 23.2lb/hr
99-01 Blue tip 49psi 22.5lb/hr

I don't know of any changes to the throttle body.

Jim www.yuccaman.com
Click to expand...
Have you noticed any gains as far as MPG, power, torque?
 
Precats? Are there more than one on the '00? Resonator perhaps? Is this something that I would have to worry about w/this manifold? Was under the assumption that this was a direct bolt-on.


EDIT: LOL, apparently I can't edit older posts?
 
This is only an educated guess, but I think the pre-cats are not part of the primary manifold(the two separate, three pipe manifolds attached to the cylinder head), but a part of the Y that connects the primarys to the single exhaust pipe leading to the cat/muffler. A 6-2-1 manifold, if you will. Have an competent exhaust shop weld up a new Y to take place of the one wit the pre-cats, and you should be fine.

Some one correct me if I'm wrong
 
Soo the precats has nothing to do w/the intake manifold itself but the exhaust manifold is what your saying(if I understand correctly)? My plan is to do the intake and a APN header at the same time. Any issues there? I've heard you may have to clearance the #6 primary tube, but other than that nothing.... ? Does anybody have a picture of this precat split exhaust manifold?
 
Last edited:
The '00 and later 4.0s use a 2 piece cast exhaust manifold, 2 "pre-cats", one on each manifold, then a traditional "Y" pipe down to the "main" cat. As long as you're staying with the earlier exhaust system, the pre-cats won't ever affect your build. Sorry, no pic.
 
Not all 2000's have precats. Mine doesn't and it was made after Jan 2000. I do frequently have the heat soak problem that you all speak of. It is quite annoying especially when you have friends around.
 
mrtosh said:
Have you noticed any gains as far as MPG, power, torque?
Click to expand...
I picked up about 1-2mpg. Seat-of-the-pants dyno indicates a possible HP/torque gain, but probably not too much. Of course, this is on a 220,000 mile 4.0L, AW-4 running 33x10.50s, 4.56s and a 4.5" lift.

Jim www.yuccaman.com
 
tbburg said:
The '00 and later 4.0s use a 2 piece cast exhaust manifold, 2 "pre-cats", one on each manifold, then a traditional "Y" pipe down to the "main" cat. As long as you're staying with the earlier exhaust system, the pre-cats won't ever affect your build. Sorry, no pic.
Click to expand...

So I was close, cats are part of the manifold, not the "Y" pipe... That sucks, I like my idea better, sounds like it's going to be more of a pain in the ass if the cats go out with this design.
 
You must log in or register to reply here.

Similar threads

M
2000-01 Exhaust Header on a 99'
2
Replies
22
Views
4K
75SV1
7
T
'95 XJ has some issues...
Replies
5
Views
1K
SleeperXJ
S
biztyke
2001 Heat soak and aftermarket header advice.
Replies
18
Views
2K
Agreen
A
S
Injector circuit error after Bosch Gen.III upgrade
Replies
0
Views
455
SubcomandanteBob
S
C
92 High Fuel Pressure/Stinks/Runs Rough
Replies
4
Views
922
tech1001
T
Back
Top