Installing a 99+ 4.0 Intake Manifold on 99- 4.0
with Banks Lookalike Header
EDIT: I posted complete word .doc with pictures, but pictures do not show. If you can repost this with the pictures, let me know. It's pretty worthless without the pictures, so I'll delete this if we can't get the pictures up too.
This is a pretty simple install. There are several good write-ups of this already, so you might want to search on the forums and read them too. I will use some of their information and pictures for this write-up. I recommend reading the shop manual procedure. Best manual is the Factory Service Manual. It is expensive, but worth every penny. Haynes and Chilton are better then nothing… sometimes, but don’t have the real detailed information often needed.
Differences between early and late 4.0 intake manifolds.
Jeep changed intake manifold designs in 99. These were fitted to XJ's, TJ's and ZJ's from mid 1999 to the end of 4.0 production. You can use one from any of these models. Jeep engineers had to come up with a way to bring the power back up after new emission changes cost them 15 hp. (Smaller exhaust ports and twin catalytic converters plus software changes among the changes). That’s why they developed the new manifold.
The new 1999 style intake manifold is on the right. Note the length and volume differences of individual runners. The 99+ manifold has individual runners of near equal length and volume. Notice that the 99+ runners are far more curved leading to the ports without the harsh right angled bends that the earlier ones have. You can also see that the plenum chamber under where the throttle body bolts on is much larger.
Notice that the plenum chamber which sits right under the throttle body is much deeper.
The old intake manifold holds 2600 cc and the new one holds 4300 cc. A throttle body spacer only adds 76 cc. There’s much more volume this new manifold is. (Some text and all pictures above are borrowed from http://www.go.jeep-xj.info/HowtoIntakeManifold1.htm ) Lots of good info on Marcus’s site. He has done some great write-ups of mods on his XJs.
Clearancing 99+ Intake for Banks Look-alike Header
If you are using a stock exhaust header this should not be a problem. Notice how much deeper the 99+ is. Make sure it clears your exhaust manifold / header before tightening it onto head! On my install, I had interference on the #6 intake manifold casting and #6 exhaust tube... I clearanced for about 1/8"+ space between them with my die grinder for about 1/16"+ on bottom of intake and flattened exhaust tube about same using a 1 1/2" socket and hammer on exhaust tube in 3 places about 3/8" apart. (Pictures at: http://www.wiedenman.com/pub/intake/ )
Lower right of picture is #6 intake.
Detail of clearancing of #6 on intake manifold.
Detail to show amount removed. Keep in mind that it is only about 1/16”. It looks like more because tape measure in not tight against manifold.
Measurement for header tube #6
Side view of flat spot in header
99+ and look-alike fit to gasket to check clearance. You can use gasket to position intake and exhaust to see what you have for clearance. You can buy this look-alike at: http://www.autopn.com/store/pc/viewPrd.asp?idProduct=20009
Detail of clearance. You can see how small the flat is on exhaust.
And how little was removed from intake manifold.
Power steering pump modifications for pre 1996 install
During the 1996 model year, Jeep changed the mounting bracket, power steering pump, and idler pulley for the power steering pump arrangement. For all ’91 –‘96 and some ‘96 Jeeps this meant getting new parts and a new power steering pump to match the new manifold. I suggest getting the needed parts from a salvage yard.
This is a copy of the parts needed at the jeep dealer or junk yard to convert a pre 1996 Jeep to use the new intake manifold. Note, # 8, 9, and 2 are not necessary. You can reuse the old parts.
Part Numbers for the steering portion of the intake swap for pre 96 4.0L’s
Part number Dealer name for part Price at my dealer
4. 34202029 bolt-hex f 136c 2.95
5. 33002201 bushing-id 114b 3.35
6. 4792112 pulley 116e 20.50 (Normal ZJ idler pulley)
7. 6503230 spacer-bel 2.70
8. 53010148 bracket 15.50
9. 53010149 sleeve-ten 5.60
10. 6503198 bolt 8.75
11. Reuse yours or hardware store
Total for the power steering parts if purchased at dealer: $59.35
This new bracket becomes the way to adjust the belt tension. You will also need to get a new serpentine belt I think part number 4060922 / 6PK2345 Goodyear Gatorback.
On the 93-95 ZJ’s the idler pulley on the new power steering bracket replaces the pulley that was below the air conditioner compressor, and the belt routing changes slightly but it was no big deal. When you remove the pulley below the AC make sure you put the bolt back in, it holds the AC bracket.
(Pics and info from; http://www.mallcrawlin.com/forum/showthread.php?t=6355&highlight=intake+manifold ) DJJordache
has spent lots of time modding his I-6.
Fuel injection modifications
(Picture from http://www.mallcrawlin.com/forum/showthread.php?t=6355&highlight=intake+manifold )
I apologize, but I don’t know who supplied this picture.
The bracket to secure the fuel lines as they pass under the manifold uses a different bolt pattern on the earlier manifold. Trim and re-drill the bracket to bolt to the 99+ manifold. You need this bracket because it holds the fuel lines away from exhaust and keeps them from vibrating.
The stock injector rail can be reused on ‘91-‘98 installs. On ’96-’98 installs you can use the 99+ injectors if you want.
“Now I scored with my intake that I bought a full set of injectors that looked like they had only done a few kms before being written off. It seemed a shame not to use them as mine had done over 110,000 kms and even though I run premium now a days and fuel injector cleaner every 5,000, they still showed a little build up. The newer ones also are completely different in construction and weighing probably only a third of the old ones. This could also mean quicker response to the electrical pulses as you always hope things get better with development! The only problem was that the old plugs do not fit onto the new injectors as the mount differently. To get around this I ground down the two tags you can see on the left new one in the picture until the overall width was the same as the old one ( 17 mm ). This then allowed the old plug the slide over the new injector but nothing to hold it there. So as you can see in the right picture I just used a nylon tie to hold them in place. Make sure the plugs still face the same way as before with the curved cut out section facing the fuel rail and that you push them all the way down engaging the pins fully. I found that when I first started that one had not seated completely so ran rough until I found which one it was and pushed it home and tighten the tie and no problems since.”(From Marcus’s Go Jeep website: http://go.jeep-xj.info/HowtoIntakeManifold2.htm )
The following is a list of the injectors used on the 4.0L since 1987 along with their rated static flow:
Model Year, ...Part #, ......Color, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, ...Black, ........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-'06, ........04854181, ...Blue tip, .....49psi, .................22.5lb/hr
As you can see, the rail pressure went up in ’96.
(From Dino’s site http://www.jeep4.0performance.4mg.com/tech_specs.html ) Lots of good info on Dino’s site.
Stock injection system is working good on my ’97. The 99+ injectors flow less fuel/hour, so may give better mileage. In the future I plan to install my 99+ injectors and see if there is an improvement.
Removal and Install of Intake and Exhaust
I suggest spraying all bolts and nuts with PB Breaker several times in the week before you do this job.
If you have a digital camera, take several pictures of wiring, cables and vacuum lines. Anything that you are not sure of remembering exactly how it was before it was taken apart.
Disconnecting battery is recommended.
(All radio presets, etc will be lost along with computer memory.)
Remove the air intake and filter box.
Disconnect throttle cable, cruise control cable and transmission cables from throttle body.
Disconnect wiring from throttle body, fuel rail and intake manifold.
Unbolt fuel rail and lay it on top of valve cover. (You do not need to remove fuel line from rail)
Remove throttle body from intake and set aside.
Loosen serpentine belt and unbolt power steering pump. Lay it where the air box normally sets.
Make sure all wiring and cables are unhooked and out of the way.
Remove bolts from exhaust manifold to header pipe.
Remove bolts from head that hold intake and exhaust on.
Now you should be able to remove them from vehicle.
(from http://www.autopn.com/products/pdf/20009_install.pdf )
Cover the exhaust pipe so nothing falls into it.
Clean old gasket off of head and put new one in place on alignment dowls.
Install the donut gasket on exhaust output.
Set the new header or exhaust manifold in place and support it with loosely installed bolts 3,6, & 7.
Start bolts 4, 2, 1, & 5 about ½ turn.
Now set the intake into place behind the washers on these bolts and on the indexing dowels in head.
(This is much easier then trying to install them after intake is in place)
Now start the rest of the bolts.
Snug all bolts up being careful that intake manifold and header set flush on gasket and head.
Tighten and torque them as best you can.
I suggest you torque one or 2 with torque wrench and then using a wrench, feel how much it takes to get that amount of torque. Then use your feel to torque them all. There is no way to get at most of them with a torque wrench.
Tighten the 2 header to exhaust bolts. \
Inspect the injector “O” rings and replace as needed. (I just put in all new ones and lube with vaseline)
Install the injector rail. (be careful of the “O” rings)
Install the throttle body and connect the cables and wires to it.
Install the power steering mount with pump and serpentine belt.
Now you can go ahead and route your vacuum lines and wiring to intake manifold.
Here’s my finished install of plumbing and wiring all hooked up. I did not have to re-set the transmission cable or throttle cable. I had to move some fittings around, splice in some hose and shorten some to get everything hooked up, but it was not a big deal.
I also did not reset the computer for engine and transmission because I was not in a “normal driving” environment. This did not seem to be an issue. Performance and mileage were good from the first crank of the key. It probably took a few hundred miles to adjust itself, but that is what it takes if you wipe computer memory anyway.
Final Performance Review
After I spent 3 days wheeling in Death Valley, I can say it works well. I got 18.5 mpg driving 70 - 80 mph on my 97 going to and from the park. Mileage when wheeling was less of course. Roads to and from have grades of 7-8% and power from 99+ intake and Banks look-alike combined with the lift and tires feels like it did with stock intake and exhaust on stock tires and no lift. Trip was on 265/75 MTs. As you know, the more aggressive the tread design, the more mileage is lost. I’m guessing that the MTs caused a lose of at least 1 – 2 mpg from what it would have been with a highway tread.
Then I drove from SoCal to central Montana following a loaded trailer average 60 mph and 22.9 mpg for 1400 miles on stock wheels and 235/75r15 street tires.
Before doing the F>R lift and changing to 99+ intake and Banks look-alike header and driving under same conditions, I got 21 mpg. Most of the time these kind of changes don't have reasonable A - B testing. Even mine is not a controlled environment, but is best I could do. Throttle body, injectors, spark plugs, wires, cat, muffler, etc. are all unchanged.
I was very careful NOT make any other changes in engine! Only other mod for trip with 22.9 mpg was 3" F>R lift. (If anything, the lift should hurt and no way it could improve mileage) Keep in mind, following an 84' Suburban with a 350 pulling a 7000 lb trailer means much more economical driving for ZJ then most drivers drive. The 22.4 mpg includes 2 hours of being stuck in traffic in Mojave Desert moving 10 miles too... and idling when stopped every hour to check trailer and stretch. (cruise control on suburban died)
I've studied this extensively and reports are mixed. A few have said they actually lost mileage. Some say little or no difference. Some say they got an improvement.
Bottom line from what I've found is that biggest improvement is in cruising speed torque. You can hold speed on grades easier in the 1800-2500rpm range. Marcus is an Australian driving an XJ with 99+ intake with exhaust mods and does lots of Outback driving. He got same kind of low end power improvement I got.
I would like to thank Marcus for his great website and articles. They can be seen at http://go.jeep-xj.info His 99+ install and exhaust for torque write-ups were lots of help.. gojeep is his user name on
and JeepsUnlimited. He has done many great write-ups.
I would also like to thank DJJordache for all his great work and write-ups: http://www.mallcrawlin.com/forum/showthread.php?t=6355 is a great write-up complete with dyno runs. Dyno runs were at 3000+ rpm because he couldn’t get shop to run from lower rpm. They were afraid it would jump off of the roller when shifting. DJJordache has a great job on his rig and documented it very well! It would be nice to know what the dyno would say from idle to 3000 rpm. That’s where we do most of our driving.
I would also like to thank Dino for all his great work. His site has all kinds of good info. He has extensive information on building strokers and performance modification. http://www.jeep4.0performance.4mg.com/index.html
There are many others who contributed information I read on the forums that I can’t remember now. I apologize for not giving them credit here too.
Good luck!
Lloyd
with Banks Lookalike Header
EDIT: I posted complete word .doc with pictures, but pictures do not show. If you can repost this with the pictures, let me know. It's pretty worthless without the pictures, so I'll delete this if we can't get the pictures up too.
This is a pretty simple install. There are several good write-ups of this already, so you might want to search on the forums and read them too. I will use some of their information and pictures for this write-up. I recommend reading the shop manual procedure. Best manual is the Factory Service Manual. It is expensive, but worth every penny. Haynes and Chilton are better then nothing… sometimes, but don’t have the real detailed information often needed.
Differences between early and late 4.0 intake manifolds.
Jeep changed intake manifold designs in 99. These were fitted to XJ's, TJ's and ZJ's from mid 1999 to the end of 4.0 production. You can use one from any of these models. Jeep engineers had to come up with a way to bring the power back up after new emission changes cost them 15 hp. (Smaller exhaust ports and twin catalytic converters plus software changes among the changes). That’s why they developed the new manifold.
The new 1999 style intake manifold is on the right. Note the length and volume differences of individual runners. The 99+ manifold has individual runners of near equal length and volume. Notice that the 99+ runners are far more curved leading to the ports without the harsh right angled bends that the earlier ones have. You can also see that the plenum chamber under where the throttle body bolts on is much larger.
Notice that the plenum chamber which sits right under the throttle body is much deeper.
The old intake manifold holds 2600 cc and the new one holds 4300 cc. A throttle body spacer only adds 76 cc. There’s much more volume this new manifold is. (Some text and all pictures above are borrowed from http://www.go.jeep-xj.info/HowtoIntakeManifold1.htm ) Lots of good info on Marcus’s site. He has done some great write-ups of mods on his XJs.
Clearancing 99+ Intake for Banks Look-alike Header
If you are using a stock exhaust header this should not be a problem. Notice how much deeper the 99+ is. Make sure it clears your exhaust manifold / header before tightening it onto head! On my install, I had interference on the #6 intake manifold casting and #6 exhaust tube... I clearanced for about 1/8"+ space between them with my die grinder for about 1/16"+ on bottom of intake and flattened exhaust tube about same using a 1 1/2" socket and hammer on exhaust tube in 3 places about 3/8" apart. (Pictures at: http://www.wiedenman.com/pub/intake/ )
Lower right of picture is #6 intake.
Detail of clearancing of #6 on intake manifold.
Detail to show amount removed. Keep in mind that it is only about 1/16”. It looks like more because tape measure in not tight against manifold.
Measurement for header tube #6
Side view of flat spot in header
99+ and look-alike fit to gasket to check clearance. You can use gasket to position intake and exhaust to see what you have for clearance. You can buy this look-alike at: http://www.autopn.com/store/pc/viewPrd.asp?idProduct=20009
Detail of clearance. You can see how small the flat is on exhaust.
And how little was removed from intake manifold.
Power steering pump modifications for pre 1996 install
During the 1996 model year, Jeep changed the mounting bracket, power steering pump, and idler pulley for the power steering pump arrangement. For all ’91 –‘96 and some ‘96 Jeeps this meant getting new parts and a new power steering pump to match the new manifold. I suggest getting the needed parts from a salvage yard.
This is a copy of the parts needed at the jeep dealer or junk yard to convert a pre 1996 Jeep to use the new intake manifold. Note, # 8, 9, and 2 are not necessary. You can reuse the old parts.
Part Numbers for the steering portion of the intake swap for pre 96 4.0L’s
Part number Dealer name for part Price at my dealer
4. 34202029 bolt-hex f 136c 2.95
5. 33002201 bushing-id 114b 3.35
6. 4792112 pulley 116e 20.50 (Normal ZJ idler pulley)
7. 6503230 spacer-bel 2.70
8. 53010148 bracket 15.50
9. 53010149 sleeve-ten 5.60
10. 6503198 bolt 8.75
11. Reuse yours or hardware store
Total for the power steering parts if purchased at dealer: $59.35
This new bracket becomes the way to adjust the belt tension. You will also need to get a new serpentine belt I think part number 4060922 / 6PK2345 Goodyear Gatorback.
On the 93-95 ZJ’s the idler pulley on the new power steering bracket replaces the pulley that was below the air conditioner compressor, and the belt routing changes slightly but it was no big deal. When you remove the pulley below the AC make sure you put the bolt back in, it holds the AC bracket.
(Pics and info from; http://www.mallcrawlin.com/forum/showthread.php?t=6355&highlight=intake+manifold ) DJJordache
has spent lots of time modding his I-6.
Fuel injection modifications
(Picture from http://www.mallcrawlin.com/forum/showthread.php?t=6355&highlight=intake+manifold )
I apologize, but I don’t know who supplied this picture.
The bracket to secure the fuel lines as they pass under the manifold uses a different bolt pattern on the earlier manifold. Trim and re-drill the bracket to bolt to the 99+ manifold. You need this bracket because it holds the fuel lines away from exhaust and keeps them from vibrating.
The stock injector rail can be reused on ‘91-‘98 installs. On ’96-’98 installs you can use the 99+ injectors if you want.
“Now I scored with my intake that I bought a full set of injectors that looked like they had only done a few kms before being written off. It seemed a shame not to use them as mine had done over 110,000 kms and even though I run premium now a days and fuel injector cleaner every 5,000, they still showed a little build up. The newer ones also are completely different in construction and weighing probably only a third of the old ones. This could also mean quicker response to the electrical pulses as you always hope things get better with development! The only problem was that the old plugs do not fit onto the new injectors as the mount differently. To get around this I ground down the two tags you can see on the left new one in the picture until the overall width was the same as the old one ( 17 mm ). This then allowed the old plug the slide over the new injector but nothing to hold it there. So as you can see in the right picture I just used a nylon tie to hold them in place. Make sure the plugs still face the same way as before with the curved cut out section facing the fuel rail and that you push them all the way down engaging the pins fully. I found that when I first started that one had not seated completely so ran rough until I found which one it was and pushed it home and tighten the tie and no problems since.”(From Marcus’s Go Jeep website: http://go.jeep-xj.info/HowtoIntakeManifold2.htm )
The following is a list of the injectors used on the 4.0L since 1987 along with their rated static flow:
Model Year, ...Part #, ......Color, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, ...Black, ........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-'06, ........04854181, ...Blue tip, .....49psi, .................22.5lb/hr
As you can see, the rail pressure went up in ’96.
(From Dino’s site http://www.jeep4.0performance.4mg.com/tech_specs.html ) Lots of good info on Dino’s site.
Stock injection system is working good on my ’97. The 99+ injectors flow less fuel/hour, so may give better mileage. In the future I plan to install my 99+ injectors and see if there is an improvement.
Removal and Install of Intake and Exhaust
I suggest spraying all bolts and nuts with PB Breaker several times in the week before you do this job.
If you have a digital camera, take several pictures of wiring, cables and vacuum lines. Anything that you are not sure of remembering exactly how it was before it was taken apart.
Disconnecting battery is recommended.
(All radio presets, etc will be lost along with computer memory.)
Remove the air intake and filter box.
Disconnect throttle cable, cruise control cable and transmission cables from throttle body.
Disconnect wiring from throttle body, fuel rail and intake manifold.
Unbolt fuel rail and lay it on top of valve cover. (You do not need to remove fuel line from rail)
Remove throttle body from intake and set aside.
Loosen serpentine belt and unbolt power steering pump. Lay it where the air box normally sets.
Make sure all wiring and cables are unhooked and out of the way.
Remove bolts from exhaust manifold to header pipe.
Remove bolts from head that hold intake and exhaust on.
Now you should be able to remove them from vehicle.
(from http://www.autopn.com/products/pdf/20009_install.pdf )
Cover the exhaust pipe so nothing falls into it.
Clean old gasket off of head and put new one in place on alignment dowls.
Install the donut gasket on exhaust output.
Set the new header or exhaust manifold in place and support it with loosely installed bolts 3,6, & 7.
Start bolts 4, 2, 1, & 5 about ½ turn.
Now set the intake into place behind the washers on these bolts and on the indexing dowels in head.
(This is much easier then trying to install them after intake is in place)
Now start the rest of the bolts.
Snug all bolts up being careful that intake manifold and header set flush on gasket and head.
Tighten and torque them as best you can.
I suggest you torque one or 2 with torque wrench and then using a wrench, feel how much it takes to get that amount of torque. Then use your feel to torque them all. There is no way to get at most of them with a torque wrench.
Tighten the 2 header to exhaust bolts. \
Inspect the injector “O” rings and replace as needed. (I just put in all new ones and lube with vaseline)
Install the injector rail. (be careful of the “O” rings)
Install the throttle body and connect the cables and wires to it.
Install the power steering mount with pump and serpentine belt.
Now you can go ahead and route your vacuum lines and wiring to intake manifold.
Here’s my finished install of plumbing and wiring all hooked up. I did not have to re-set the transmission cable or throttle cable. I had to move some fittings around, splice in some hose and shorten some to get everything hooked up, but it was not a big deal.
I also did not reset the computer for engine and transmission because I was not in a “normal driving” environment. This did not seem to be an issue. Performance and mileage were good from the first crank of the key. It probably took a few hundred miles to adjust itself, but that is what it takes if you wipe computer memory anyway.
Final Performance Review
After I spent 3 days wheeling in Death Valley, I can say it works well. I got 18.5 mpg driving 70 - 80 mph on my 97 going to and from the park. Mileage when wheeling was less of course. Roads to and from have grades of 7-8% and power from 99+ intake and Banks look-alike combined with the lift and tires feels like it did with stock intake and exhaust on stock tires and no lift. Trip was on 265/75 MTs. As you know, the more aggressive the tread design, the more mileage is lost. I’m guessing that the MTs caused a lose of at least 1 – 2 mpg from what it would have been with a highway tread.
Then I drove from SoCal to central Montana following a loaded trailer average 60 mph and 22.9 mpg for 1400 miles on stock wheels and 235/75r15 street tires.
Before doing the F>R lift and changing to 99+ intake and Banks look-alike header and driving under same conditions, I got 21 mpg. Most of the time these kind of changes don't have reasonable A - B testing. Even mine is not a controlled environment, but is best I could do. Throttle body, injectors, spark plugs, wires, cat, muffler, etc. are all unchanged.
I was very careful NOT make any other changes in engine! Only other mod for trip with 22.9 mpg was 3" F>R lift. (If anything, the lift should hurt and no way it could improve mileage) Keep in mind, following an 84' Suburban with a 350 pulling a 7000 lb trailer means much more economical driving for ZJ then most drivers drive. The 22.4 mpg includes 2 hours of being stuck in traffic in Mojave Desert moving 10 miles too... and idling when stopped every hour to check trailer and stretch. (cruise control on suburban died)
I've studied this extensively and reports are mixed. A few have said they actually lost mileage. Some say little or no difference. Some say they got an improvement.
Bottom line from what I've found is that biggest improvement is in cruising speed torque. You can hold speed on grades easier in the 1800-2500rpm range. Marcus is an Australian driving an XJ with 99+ intake with exhaust mods and does lots of Outback driving. He got same kind of low end power improvement I got.
I would like to thank Marcus for his great website and articles. They can be seen at http://go.jeep-xj.info His 99+ install and exhaust for torque write-ups were lots of help.. gojeep is his user name on
and JeepsUnlimited. He has done many great write-ups.I would also like to thank DJJordache for all his great work and write-ups: http://www.mallcrawlin.com/forum/showthread.php?t=6355 is a great write-up complete with dyno runs. Dyno runs were at 3000+ rpm because he couldn’t get shop to run from lower rpm. They were afraid it would jump off of the roller when shifting. DJJordache has a great job on his rig and documented it very well! It would be nice to know what the dyno would say from idle to 3000 rpm. That’s where we do most of our driving.
I would also like to thank Dino for all his great work. His site has all kinds of good info. He has extensive information on building strokers and performance modification. http://www.jeep4.0performance.4mg.com/index.html
There are many others who contributed information I read on the forums that I can’t remember now. I apologize for not giving them credit here too.
Good luck!
Lloyd
Last edited:
