gutless YJ

[sicnik]

my 93 YJ is gutless in 5th gear specially going up an incline I know its a 4 banger but this is pitiful. I changed all the wires, plugs, dist cap and rotor have K&N air filter which seems to have improved it somewhat but 5th gear still needs someone to get out and push. any suggestions?

 

[Junkpile]

What size tires are you running and what is your differential gear ratios. If you have added taller tires and haven't regeared that is the reason fifth is useless. The 2.5l doesn't have any lowend torque, and the overdrive is almost too tall of gearing for the factory tires. Taller ones make overdrive useless unless you go to a higher(numerically) axle gear to get the engine back into it's operating range.

If it's all factory and you still aren't satisfied.......it's a four banger, what do you expect? Do the normal high flow filter, header, free flowing exhaust, and 4.0 TB to add a few more ponies. There are roller rockers and more aggressive camshafts out there, along with several other "next step" parts if you want to get serious and spend some money. Those engines respond well to head porting and shaving too, especially if you do the other listed mods. You want to enhance upper rpm breathing and get used to spinning it all the way to the redline if you want to get anything out of it because that engine will never have any real lowend torque, no matter what you do.

 

[Tug-n-pull]

OMG Spank them kids 2 (TWO)

That is the only down fall to the 4 banger in a Jeep. There are some things that people do to help but there is nothing short of getting a bigger motor or spending major bucks to make the little engin that can seem bigger. Other than letting it breath via the intake and exaust, you can install an electric fan and remove the clutch fan to free up what ever ponies turn the fan. there are several other benies that come with this mod. I have heard of folks building an external flywheel enertia ring to incress the torque but you would have to do a search on that one. Be kinda like the one you see on the front of a big deseil engin.

Even then it is all for the high gears on the road cause once you little 4 banger gets into its zone that being off road it is a beast for it's size. I am one of the folks that love the little engin. Off road they are my choice for the type of riding I enjoy in my area. Good luck and remember it's just little so be nice to it. tug

 

[mud4feet]

any suggestions?

Stay in 4th - works for me. Can't remember the last time I used 5th in my '03 4banger ('tho I know it had to be on a downhill grade!). I really don't enjoy drivin' the highways, anyway, and, like Tug says, those li'l 4bangers do just fine off road.

 

[Special_K]

When you are going up an incline in 5th gear, have some in the passenger seat to push on the dash. :lol:

Seriously though, I think that's the problem with 4 bangers. I had a roommate some years back who had one. Same problem. I even tried pushing on his dash when we were going up an incline but it only succeeded in pissing him off more. :lol:

The most complete solution might be to put trade up to a cool 6 cyl or do an engine transplant to finally give it some guts.

 

[Bounty__Hunter]

The inertia ring does nothing to increase torque, it merely helps the 2.5L stay spinning between power strokes of each cylinder, helps at low rpm when crawling.

I run a 2.5L 5spd, stock 4.11 gears, and can turn my 33x12.5 TSL Radials at around 80 on the interstate, but that's in 4th. I can use 5th on the flat if conditions are right, but I've done a lot of power mods.

4.0L TB and spacer, airtube, Flowmaster muffler, electric fan, Mopar Performance Stage II cam (256*/.450"), performance valve springs. I'll eventually regear to 5.38 when the D44's are done being built.

 

[Special_K]

I can use 5th on the flat if conditions are right...

If conditions are right? Does that mean a very, very strong tail wind...like when you have a tornado or hurricane right behind you. :lol:

I'm sorry I couldn't resist. Bad me. No offense intended.

 

[hi_c]

You cry babies! At least you have MPFI. I have 2.5L with TBI, which is like 20hp weaker. You need to start losing weight, ie., chunk heavy rocker guards, remove your backseat (and hence, any passengers), get skinnier tires (I have 33x10.50, not 12's), get better air flow (K&N, exhaust mods), and get rid of A/C (if you got it). Otherwise, you'll have to dip into the wallet to get 5th back like it was stock (new motor, new gears, etc.). Personally, I just live with it. I can only do 65 on flat roads.... in any gear! '89 YJ with 168K miles. I figure when I start breaking axles and have to get new ones, I'll invest in some new gears. (keep the D30, and upgrade to 8.8 with matching 4.88 gears.)

I like the light weight.

corey

 

[Bounty__Hunter]

Ditto on the light weight, I do as much as possible to keep it light short of removing the cage and rocker skids.

hi_c brought up another good point on tires. Tall is fine, but consider the narrower tires when running the 2.5L, less rotating mass to get moving and keep moving. Less wind resistance but that gain is mimimal compared to weight. I'll probably end up with the 34x9.5 when I switch to my 6-lug rims, too bad I can't afford aluminum wheels.

 

[sicnik]

Ok, so I guess I am going to have to find some dirt/mud roads to take to work and stay off the highway.. that may make going to work more fun.
I changed all the wires, rotor, dist cap, plugs, and changed the ignition coil today, plus cleaned my K&N. Its doing great as long as I dont go over 65 mph. I think im going to invest in a new exhaust, my catastrophic converter is plugged and my O2 sensor is probably shot, so my new question is this, can I straight pipe my exhaust cut out the cat, and not effect the O2 readings? the sensor is up by the oil pan..

 

[Tug-n-pull]

By all means if you do not have a state inspection get rid of that cat and put yourself a good quality free flowing muffler on that puppy. Go for a series 30 Flowmaster and you will not believe the sound you get out of that little 4banger not to mention the extra power and mpg. Now granted the 30 is not the quiest muffler on the market but man does it sound low and throaty on the little engin. If your cat is shot that may be your biggest problem anyway. tug

 

[sicnik]

so dropping the cat wont mess up the O2? My cat currently has a nice screwdriver hole in it...hehehehe! sonds nice and rough.

 

[sicnik]

sounds......hell you think a HS education I could at least spell!... must be the beer.

 

[Tug-n-pull]

MOpe it is only on there to make you life hard. get ride of it! tug

 

[berettajeep]

By all means if you do not have a state inspection get rid of that cat and put yourself a good quality free flowing muffler on that puppy.

Tampering with the emissions is illegal :roll:

 

[sicnik]

Reverse Lights

Not in kansas, if so who cares.......I guess that is not very greenpeace of me is it........lmao......yeah right who am i kidding.

 

[Bounty__Hunter]

You won't affect the o2 sensor or computer since the sensor is upstream from the catalytic converter. You will likely fail emissions if testing is required in your area. And yes it violates federal emissions law, but it's your choice.

 

[Junkpile]

Yeah, I forget to mention that part, keeping the rig lightweight is the most important thing to living with the 2.5. I had a 2.5L YJ too, 93 model. I stripped it completely down. Nothing on the interior that wasn't required to drive the vehicle. No winch, no heavy bumpers or skidplating, everything under the hood was gone except what it took to drive. Aluminum wheels, and anything else I could replace with aluminum or plastic was gone. No spare, and no jacks or tools. I raced mine alot, and the lighter weight not only made it faster, it helped keep drivetrain components from breaking. Even with 36x12.50 Swampers it weighed 2920lbs.(maybe 2980, I can't remember.....) . It would run over 100 and was actually pretty quick up to about 50, but I don't think I could hold fifth over about 70 with the factory gearing......and that was on flat land with no headwinds.

 

[beachjeep]

Health Insurance

Hey Bounty - Mopar Performance Stage II cam (256*/.450") - what kind of performance push does this give and how much $ are we talking about? Just curious more than anything.

 

[sicnik]

I know its illegal, and should'nt be done but the fed's dump more crap in the atmosphere than my jeep ever will......how ever I do not want o be a part of the problem and if I can fit it into my budget I will replace the catastrophic convert, to keep the world safe from my green house gasses....but anyway thanks to you all for your help, I will probably end up replacing everything in my jeep anyway........helps pass the time ya know + it pisses the 1/2 off.