More Power?????
06-29-2008, 12:15 AM
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Model: Cherokee
More Power?????
I just got a late 80s jeep cherokee 4 door, it has 2.5 liter throttle body injection,way gutless! any ideas on how to get a little more horses without a new motor???
06-29-2008, 11:15 AM
#3
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The best be other than motor swap on the 2.5L is to cross ref. what car motor it's based on than start looking at tuner parts..
Just as a ref. the 2.4L in the '04 and new TJ's is right out of the Neon so all Neon tuner parts work also on the TJ's.
I do think the older XJ 2.5's was based on the "Iron Duke" from the CJ days. If that's the case there should be some torq add-ons. I also think there are a few cams for it.
The other good way to gain some power is to regear, you should have 4.10 gears if your running stock tires I'd say 4.56 gears would be better. I hope this help you a bit. If you give some more details on year of your Xj and options I can do a search and find some more details out about your motor..
Nick
Just as a ref. the 2.4L in the '04 and new TJ's is right out of the Neon so all Neon tuner parts work also on the TJ's.
I do think the older XJ 2.5's was based on the "Iron Duke" from the CJ days. If that's the case there should be some torq add-ons. I also think there are a few cams for it.
The other good way to gain some power is to regear, you should have 4.10 gears if your running stock tires I'd say 4.56 gears would be better. I hope this help you a bit. If you give some more details on year of your Xj and options I can do a search and find some more details out about your motor..
Nick
06-29-2008, 11:22 AM
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The AMC I4 first appeared in 1984 with the new XJ Cherokee. It was produced through 2002 for the Jeep Wrangler, as well as for the Dodge Dakota pickup that also used the AMC/Jeep designed four since 1996.
06-29-2008, 12:21 PM
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Year: 90
Model: Cherokee
Engine: 4.0
I do think the older XJ 2.5's was based on the "Iron Duke" from the CJ days. If that's the case there should be some torq add-ons. I also think there are a few cams for it.
The other good way to gain some power is to regear, you should have 4.10 gears if your running stock tires I'd say 4.56 gears would be better. I hope this help you a bit. If you give some more details on year of your Xj and options I can do a search and find some more details out about your motor..
Nick
Nope.. no relation between the two motors.. Jeep ditched the Iron Duke in CJ's in favor of the AMC/Jeep 2.5l...
There were some power parts though..
A handful of cams.. the ubiqutious Throttle Body Spacer(on his motor it will actually do something)... IIRC they used a GM-style injector so there were hi-flow injectors available. And of course high-energy ignition.
But the quickest way to squeeze more power from those little ponies is more air and OUT of your engine.. a hi-flow exhaust and cold air intake will help....
06-29-2008, 03:59 PM
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The best be other than motor swap on the 2.5L is to cross ref. what car motor it's based on than start looking at tuner parts..
Just as a ref. the 2.4L in the '04 and new TJ's is right out of the Neon so all Neon tuner parts work also on the TJ's.
I do think the older XJ 2.5's was based on the "Iron Duke" from the CJ days. If that's the case there should be some torq add-ons. I also think there are a few cams for it.
The other good way to gain some power is to regear, you should have 4.10 gears if your running stock tires I'd say 4.56 gears would be better. I hope this help you a bit. If you give some more details on year of your Xj and options I can do a search and find some more details out about your motor..
Nick
Just as a ref. the 2.4L in the '04 and new TJ's is right out of the Neon so all Neon tuner parts work also on the TJ's.
I do think the older XJ 2.5's was based on the "Iron Duke" from the CJ days. If that's the case there should be some torq add-ons. I also think there are a few cams for it.
The other good way to gain some power is to regear, you should have 4.10 gears if your running stock tires I'd say 4.56 gears would be better. I hope this help you a bit. If you give some more details on year of your Xj and options I can do a search and find some more details out about your motor..
Nick
Ok its a 86 cherokee 4dr 2.5liter throttle body,make is AMER style is 4W and model is CHK it has a three speed auto,,,, does anyone know what model the trans would be in that???
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06-29-2008, 07:25 PM
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does anyone have pictures of how the cooling lines hook up to that trans,picked up the jeep last week for 150 dollars,it looks like the previous owner cut the cooling lines and threw in rubber hoses,they seem to be leeking,leaves a trail whever you accelerate,everything thing is covered in grime i want to be able to go straight to the hook up and replace the lines.....pictures would be awesome??????
06-30-2008, 05:35 AM
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Year: 1996
Model: Cherokee
Engine: 2.5L I-4
As soon as I saw the title of this thread, I knew somebody must've bought a 4-banger. 
Like BlueXJ said, I'm running the 2.5L as well, and there are plenty of ways to squeeze some power out of it.
First off, get a throttle body spacer and swap your throttle body with one from a 4.0L. The 2.5 and 4.0 engines come with the same diameter throttle intake, but the 2.5 throttle body is a few millimeters tighter, choking the engine of much needed air.
Swap your enclosed air filter element for a K&N style cone filter and hard-bent air tube (cold air intake).
Also, I assume it has a clutch-style fan like mine. The clutch fan robs 12-14 hp just to run it, so swap it for an electric fan. Any auto parts store will sell you a 16" electric fan, and you can use 1/8" aluminum to bend up a fan shroud. Or you can go junkyard diving for a fan from a Ford Taurus.
You'll see night and day differences if you do these simple things. Re-gearing will also help, but it won't put any more power through the engine, it just won't have to work as hard.
Hope this helps.
Like BlueXJ said, I'm running the 2.5L as well, and there are plenty of ways to squeeze some power out of it.
First off, get a throttle body spacer and swap your throttle body with one from a 4.0L. The 2.5 and 4.0 engines come with the same diameter throttle intake, but the 2.5 throttle body is a few millimeters tighter, choking the engine of much needed air.
Swap your enclosed air filter element for a K&N style cone filter and hard-bent air tube (cold air intake).
Also, I assume it has a clutch-style fan like mine. The clutch fan robs 12-14 hp just to run it, so swap it for an electric fan. Any auto parts store will sell you a 16" electric fan, and you can use 1/8" aluminum to bend up a fan shroud. Or you can go junkyard diving for a fan from a Ford Taurus.
You'll see night and day differences if you do these simple things. Re-gearing will also help, but it won't put any more power through the engine, it just won't have to work as hard.
Hope this helps.
Last edited by TrueBlueXJ; 06-30-2008 at 05:40 AM.
06-30-2008, 09:04 AM
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Year: 1996
Model: Cherokee
Engine: 2.5L I-4
Just happy to be of some use around here.
Now I'm not entirely sure that throttle body trick will work on the pre-91 2.5s, but I could be wrong.
The biggest thing for these motors, though, is air flow. A cold air intake and an aftermarket cat-back exhaust are going to give you the most improvements on that front. I run the Dynomax Super-Turbo cat-back system, and I noticed an immediate difference after the install. Since then I've added a throttle body spacer, and am awaiting the funds to purchase a 4.0 TB and cold air intake. Once I get the proper air flow going through this thing, the electric fan swap is next on the list.
Here are some write-ups on the mods I've mentioned:
2-speed electric fan swap
2.5 to 4.0 throttle body swap
Now I'm not entirely sure that throttle body trick will work on the pre-91 2.5s, but I could be wrong.
The biggest thing for these motors, though, is air flow. A cold air intake and an aftermarket cat-back exhaust are going to give you the most improvements on that front. I run the Dynomax Super-Turbo cat-back system, and I noticed an immediate difference after the install. Since then I've added a throttle body spacer, and am awaiting the funds to purchase a 4.0 TB and cold air intake. Once I get the proper air flow going through this thing, the electric fan swap is next on the list.
Here are some write-ups on the mods I've mentioned:
2-speed electric fan swap
2.5 to 4.0 throttle body swap
06-30-2008, 09:15 AM
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Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
Good read even for a 4.0L guy like myself. The same kind of improvements work with many different engines. I view an engine as an air pump. The more air in and out the more efficient and powerful they become. Just a rule of thumb in most cases but a rule nonetheless.
06-30-2008, 09:55 AM
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As soon as I saw the title of this thread, I knew somebody must've bought a 4-banger.
Like BlueXJ said, I'm running the 2.5L as well, and there are plenty of ways to squeeze some power out of it.
First off, get a throttle body spacer and swap your throttle body with one from a 4.0L. The 2.5 and 4.0 engines come with the same diameter throttle intake, but the 2.5 throttle body is a few millimeters tighter, choking the engine of much needed air.
Swap your enclosed air filter element for a K&N style cone filter and hard-bent air tube (cold air intake).
Also, I assume it has a clutch-style fan like mine. The clutch fan robs 12-14 hp just to run it, so swap it for an electric fan. Any auto parts store will sell you a 16" electric fan, and you can use 1/8" aluminum to bend up a fan shroud. Or you can go junkyard diving for a fan from a Ford Taurus.
You'll see night and day differences if you do these simple things. Re-gearing will also help, but it won't put any more power through the engine, it just won't have to work as hard.
Hope this helps.
Like BlueXJ said, I'm running the 2.5L as well, and there are plenty of ways to squeeze some power out of it.
First off, get a throttle body spacer and swap your throttle body with one from a 4.0L. The 2.5 and 4.0 engines come with the same diameter throttle intake, but the 2.5 throttle body is a few millimeters tighter, choking the engine of much needed air.
Swap your enclosed air filter element for a K&N style cone filter and hard-bent air tube (cold air intake).
Also, I assume it has a clutch-style fan like mine. The clutch fan robs 12-14 hp just to run it, so swap it for an electric fan. Any auto parts store will sell you a 16" electric fan, and you can use 1/8" aluminum to bend up a fan shroud. Or you can go junkyard diving for a fan from a Ford Taurus.
You'll see night and day differences if you do these simple things. Re-gearing will also help, but it won't put any more power through the engine, it just won't have to work as hard.
Hope this helps.