Topic: 89' 2.5 - Stock for now

[codyman]

Hello.  I'm new to this site but I'm glad to be here... its tough finding a support group for the 2.5 in a world that seems to be dominated by 4.0's  :(

I have an 89' 2.5 that's completely stock except for rims (actually really nice chrome ones that the previous owner bought) and some bigger tires (can't remember dementions but belive they are 30's -- they need to be replaced though, they're aging and are nearly bald), sound bar / stereo, and nicer replacement front seats.  The condition of the vehicle (appearance whise) is flawless.  Its original paint (white) yet has not a single dent, swirl, discoloration, etc etc (I'm pretty sure this wrangler has NEVER seen dirt... I'll try to change that  :D ).  The interior is also flawless.  Now for the bad news: The exhaust is pretty rusted and the bolt on the exhaust manifold backs off about once a month (I hear you should use loc tite on it??)... that's ok cause I want to put something custom in to free up power anyways.

This is not my daily driver, its more of my weekend / cruise with the friends vehicle.  Somewhere down the line I might want to take it on a very mild trail but I don't plan on traversing rocks etc etc.

I live in a small but hilly town on the Southern California coast... I want to boost the performance of the 2.5 because of the hills.. we're talking 2nd gear and stepping on it to get it up these things... So far here are my plans (please add any suggestions)

1.  Exhaust (maybe even new cat??)
2.  Tune Up (Plug wires, plugs, air filter, cap rotor, fuel filter etc etc)
3.  Tires (Probably go with the same 30's, just milder sidewall)

I wish I could do something like the 4.0 poweraid tb spacer, but unfortunately its an 89' with tbi...

So, what else is there for me to do to add power?  (Note: I want to stay away from changing gear ratios.... long story....)

Thanks for reading my long jabbering....  :shock:

[87AMC_YJ]

Codyman...I feel your pain.  I have an '87 that I purchased in SoCal a couple of years ago with 118K on it.  In between deployments to the Persian Gulf waters I work on it.  I located a K&N filter for a good price ($20 or so) at TURBO CITY (web site) and listed in their close out section.  Also, change out all the vacume hoses you can get your hands on.  They are the source of a lot of trouble/lost performance on a TBI YJ.  A while back I think I saw a $300+ header shown on a "Clifford Performance" site. They specialize in 4 and 6 cylinder hop ups.  I haven't seen any other sources for headers for the 150 c.i. engines.  If you know of one, please let me know.   I purchased a MSD Series 6A ignition system on line the other night (I'm at sea now), but it will March before I'm home again and can install it.  I'll let you know how it works out.  Having my TBI injector professionally cleaned helped also.  Becareful tightening up the exhaust bolts.  I had one break off with hardly any pressure on it and that exhaust leak is messing with the TBI vacuum settings.  If you are on a budget (like me), check out High Tec Retread tires.  I got a great set of OTR MUD tires for about $300 (29" tall) to replace my dry rotted 215  series stock tires.  They have worked great in the muddy forrests of WA state, but maybe not what you need in SoCal.  Anyway...good luck.

[codyman]

Thanks for all the info.  I'm DEFINATEL'Y on a budget as well considering I'm a senior in high school.... I got this car for free because I "adopted" it from my dad who lost interest in fixing it up.

I will look into replacing the vacuum hoses becaus I need to do that anyways since when I shift into 4wd, the 4wd light does not come on and it doesn't engage (It has worked in the past but I believe a vacuum line tot he transfer case is either bad / loose).

With your suggestions, right now I'm going to focus on:
1.  Tune Up w/ K&N Filter
2.  Exhaust System (Cat-Back + Fix Exhaust Manifold Leak)
3.  Tires
4.  Clean TB
5.  Replace Vacuum Hoses
6.  Maybe MSD Ignition (Tell me how it goes)

On another note, stay safe out there at sea.  Both my Grandpa and Uncle served in the navy along with another Grandpa in the airforce during WW2 so I understand the sacrafices it takes to serve our country.  You should be proud at what you're doing and you have my utmost respect.  Saying that you bought the wrangler in SoCal.. I'm assuming around Camp Pendleton maybe?? (I live in San Clemente, 1st town North of base).

Take Care + God Bless America and Our Service Men
  - Cody

[shotgun]

I filed this in the back of my head. Rusty's has an 87-89 Throttle body spacer. They say it's for  XJ and YJ 4.0L engines. I recall the XJ had a short run of NON-H.O. injected engines. But the yj stayed carburated till 91.

http://rustysoffroad.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=rustys&Product_Code=TBS25&Category_Code=PER_AIR

I can't say that it will fit. I just filed it as a look into it further later item.

[codyman]

hmm.. looks interesting.  I wonder if it has ever been tested / adapted to the 87-90 2.5?  Don't want to spend $60 bucks and find it doesn't work but maybe I'll email rusty's and get the dementions of it and compare it to the tb of my 2.5??

[Jeffy]

Well, I'll start off with some damage control.  The '87-'90 2.5L's were not carburated.  They were just not MPFI.  The 4.0L's that the XJ's used from '87-'90 used a Renix Fuel Injection system.  YJ's never got the early 4.0L's but rather the 4.2L from the CJ's.  This system has a computer controlled Carter BBD.

There was a guy on the mailing list who was making TBI spacers for under $50.  He was a CNC guy doing it in his off time.  I'm not sure if he's still around though.

Honestly, thoughwith 30" tires you can't be that hard up on power unless something else is wrong.  Here's what I'd do though.

I'd do a complete Cat-back and cat.  The Jeep is old and so is the cat so it's a good time to replace it all.  Personally, I like Carsound's Hi-flow cat.  It's a lot smaller then the OEM, too.  As for the rest of the exhaust, I'd go with a stainless steel system.  I like bolt-on kits since I'm able to install it and fix it without having to cut or weld.  A lifetime warranty is pretty common for the larged companies.  This means if something breakes like the muffler or hangers, you usually send in that piece after they send you the replacement.  This is another reason why I don't weld it.

Honestly, unless you're going to do some major intake work, you probably won't gain much from a header.  Depending on the design, you may actually loose low-end torque for high-end horsepower which isn't good.  Clifford is ok but you're going to have to get a crossover pipe made.  Borla and Banks also make desent headers.  Although if yours is fine, then I'd probably leave it.

I'd also consider upgrading the ignition.  A MSD is nice but you can go simplier with something like a hoter coil and better plug wires for less.  This will help you get a more efficent burn which may help the torque out a bit.

As for the K&N, some guy's like them while others don't.  I went back with the standard paper filter.  The problem with K&N's is that unless you run a prefilter which defeates the whole purpose of running a K&N, you will probably see dust in the intake.  This is more common in dustier area like the desert around Socal then someplace back east.

One thing you haven't said is if you have a manual or automatic.  That makes a huge difference.  As for gearing, 30" isn't really worth it.

[shotgun]

Sorry Jeff, I could/should  have made this clearer.

I filed this in the back of my head. Rusty's has an 87-89 Throttle body spacer. They say it's for  XJ and YJ 4.0L engines. I recall the XJ had a short run of NON-H.O. injected engines. But the yj stayed carburated till 91.

http://rustysoffroad.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=rustys&Product_Code=TBS25&Category_Code=PER_AIR

I can't say that it will fit. I just filed it as a look into it further later item.

The rusty's spacer says it is for xj and yj 4.0L engines. I had remembered this item because I recalled the 87-90 XJ cherokee and MJ commache had a non high output  injected engine(Ie. the Renix system) I knew it could not be for any 87-90 6 cylinder yj as you pointed out they were actually 4.2 Liters and carburated.

I was anticipating that the Throttle body used  for the 87-90 XJ and MJ was close enough to the same setup as the 2.5L, to be of use. In the true spirit of Jeep, I was hoping to adapt a part for my use although it was intended for another application.

Once again I apologize for any confusion my post may have caused.

[Jeffy]

What you'll want to do is go to the auto parts store and look up the gasket for your TBI, then look up the gasket for the 4.0L.  That's how we figured out if the 4.0L TBS would work on the 2.5L. (This was way before the 4.0L swap)

[codyman]

For the record I have a 5 speed.

Do you think you could track down the guy that was making tb spacers?  I don't know where the mailing list is....

Do auto parts stores carry tb gaskets for 4.0 / 2.5 (Reason I ask is because honestly no matter what vehicle I clean the throttle body (dodge / ford / anything) I always either have to make my own tb gasket or get it from the stealership....

[rojogordo]

I also have an '89 4-banger. The thing that degrades power the most in mine is weak spark. I'm going to DUI & livewires asap.

rojogordo

[Guardian7]

I also have an 89 4banger, the TB spacer on Rusty's site is nothing like my 89 has which is rectangular with 4 bolts, I have a friend who makes them for  me at his machine shop.

[Got Wood?]

Hey guardian, do you have a noticeable difference with the spacer?Is it worth it to have? thanks

[Guardian7]

We are still testing prototype designs, my 1st test has a parabolic curve in the bore which reduced the total CFM as the bore size grows smaller towards the bottom causing restriction. This has improved mileage but we want to increase power and torque so next we will machine the bore straight and retest which is what Jeffy suggested to me.
http://www.4bangerjp.com/forums/viewtopic.php?t=1047

[superman1456]

it all depends on how big your money tree is lol  :D  if you what power then go for power if you whant good mpg then go for that but then agan i am more of a 4.0 person myslef as i own 2 of them a 1994 2wd cherokee with the 4.0 ho in it and a 1999 grand cherokee but when it comes to power think of it this way your engin is like you the easer you can breathe the hepper you are  :D so my advice is exaust intake Ignition and head work but as you sad you are on a budjet so go easy start small and work your way up maby one day you will put a 4.0 in it who knows but for now worry about thoues things i just said and good luck and let me know what you do

[Guardian7]

I agree with Superman, "exaust, intake, Ignition" those are best things we can do for more power unless you have lots of money which most of us dont. And 4bangers need every little bit of power we can sqeeze from those 2.5L engines especially when running larger tires needed to hardcore wheelin. I hope to make my next purchase a performance distributors ignition system like the unit reviewed in Nut & Bolts section.