I got my hands on a 99 TJ yesterday and took off the intake manifold. Im gonna take out the fuel injectors and a couple things and then sandblast it at school. After that, what are my options as far as cleaning it up and polishing it and even porting it a little (gasketmatching prolly). Ive heard these things can give you 15+ hp but it sounds a little unreasonable, I could also sell this on ebay, one just went for $130 yesterday. In any case, I was just reading through the other thread about porting a cylinder head but i figured this was a litlte bit different. Any ideas or experience is appreciated.
-
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.
99+ Intake Manifold Modifications
- Thread starter BBeach
- Start date
goodburbon
NAXJA Forum User
- Location
- Westcliffe Colorado.
I did the swap and port matched my head while I had the manifold off. Just have to be sure to seal the valve area very well and clean up afterwards so you don't get trash in the combustion chambers.
Dr. Dyno
NAXJA Forum User
- Location
- Al Ain, UAE
BBeach said:
It IS unreasonable. You'll gain roughly 3hp/6lbft from swapping a '99+ manifold onto an earlier 4.0 engine.
I did see a black box filled with black pellets on it, im assuming that was the emissions stuff that could have drained hp. For example, it 190hp-say 10hp for the emissions then +13 resulting in a net of 193 thus making it +13 on a 98??? Im pretty sure that if i ported/cleaned it up and polished it it would make more power as well. So I can clean up my cylinder head as long as i plug it up before the "elbow" near the valves? Is the new manifold a plug and play or do i need to lengthen anything? Im just debating between selling it. It has blue injectors (any specs on these anyone?) and seems in decent shape. How much do you think id be able to get all assembled, I saw a bare one go for $130 yesterday on ebay.
goodburbon
NAXJA Forum User
- Location
- Westcliffe Colorado.
I had to lengthen my IAT sensor wires, and re-arrange the vac lines, but other than that it was a direct fit. If you have a pre-96 ish model there are some Power steering pump mounting issues.
Dr. Dyno
NAXJA Forum User
- Location
- Al Ain, UAE
cjovertj said:
Who said they lost 15hp anyway? They lost 5hp/3lbft with the 0331 head but they regained 5hp/4lbft with the cam and 3hp/5lbft with the intake manifold, so the rating went up for the XJ 4.0 from 190hp/225lbft in 1999 to 193hp/231lbft in 2000.
Dr. Dyno said:
i read it somewhere i thought it was on here but maybe it was on pirate
you are probably right i was just saying what i heard, and with all the people who have used it and said they felt a significant hp increase it seems like 15hp would be about right, but like i said i might be wrong
goodburbon
NAXJA Forum User
- Location
- Westcliffe Colorado.
cjovertj said:
If I believed all of the numbers thrown around by performance companies and webwheelers I should have a 250 hp 4.0
Bored TB
Ford injectors
99+ intake
jet stage 2 chip and 180* Tstat
dual electric fans
Port matched head
Banks header
3" exhaust and flowmaster
Open element air filter
TB spacer
Accel 8.8mm plug wires
and I even had a Jacobs pro-street ignition at one point.
Fact is, though it runs strong, It's not nearly what it was advertised it would be.
Slo-Sho
NAXJA Forum User
- Location
- The 2nd most regulated state.
^
May I ask what size Ferd Injectors you're running? What year is the Head/Block?
May I ask what size Ferd Injectors you're running? What year is the Head/Block?
I read on http://www.go.jeep-xj.info/HowtoIntakeManifold1.htm that it gives a good amount of power. They tested it n a dyno as well, but i believe there are other variables such as they took off the clutch fan and such.Dr. Dyno said:
goodburbon
NAXJA Forum User
- Location
- Westcliffe Colorado.
19# injectors
it's a '97.
it's a '97.
j99xj
NAXJA Forum User
- Location
- Colorado Springs, CO, USA
I think injectors were swapped along with the intake with the big dyno numbers.
So the hp gain isn't all from the intake. (the old injectors were probably junk)
So the hp gain isn't all from the intake. (the old injectors were probably junk)
From the GoJeep Website : "DJJordache posted a write up here showing that swapping to this along with the Hesco fuel pressure regulator and 99 injectors, as I have also done also, showed 26.9 hp and 19.7 rear wheel torque at the rear wheels comparing on the same dyno before and after the swap." Its got the 99 injectors on it and i already did the clutch fan elimination. I doubt a fuel pressure regulator could account for a majority of the power increase. And this is the original site http://www.mallcrawlin.com/forum/showthread.php?t=6355 . So in any case, if they're saying that the new manifold/injectors and clutch fan elimination is 27rwhp gain, then im fine with that.j99xj said:
j99xj
NAXJA Forum User
- Location
- Colorado Springs, CO, USA
I (well acutally Dr. Dyno) was saying the old injectors were probably clogged and causing the engine to run lean resulting in a massive power loss.
Michaelarchangelo
NAXJA Forum User
- Location
- Daytona Beach
That is the IAT
Alrite because i think it broke when it was in the accident. The part that plugs in from the jeep is stuck in there so if i just get it out id be all set. In any case, its always possible to just relocate the IAT elsewhere correct? The only problem is i dont use the stock airbox, ive got a rustys airtube instead. Does my 98 connection plug right into the 99 one or do i have to lengthen the wires? Thanks a lot for the response btw, that was what i was hoping it would be.Michaelarchangelo said:
Michaelarchangelo
NAXJA Forum User
- Location
- Daytona Beach
You can relocate it into the airtube, but you will have to lengthen the wires. The harness should be the same between 98 and 99.
How am i going to relocate it if the plug end of the sensor in the manifold is destroyed? Do i have to buy a new sensor and remove the old one from the manifold? Is it pressed in or threaded? Im going to have to seal it pretty well too when i put it in. Any ideas?Michaelarchangelo said: