No power when starting on a hill

[hogelectra]

OK this is interesting. Took the MJ out the first time on a medium level trail and learned a lot about the jeep.

What I learned:

 

1. The rear lower shock mounts are in the wrong place - moving them up off the axle

2. Skid plates for the transmission and transfer case are worth their effort

3. Rock sliders are also worth the effort

 

Now the problem. After 5 hours I finally got to a point where I no longer need 4Low and switch to 4H. I was on a very slighjt hill and when I let the clutch out it felt like I had the parking break on and the engine would die. Even tried 2H and got the same response. It would work as long as I was on level ground. Switched back to 4Low and it works.

 

The guys on the run with me suggested a vacuum leak - so I tracing that down.

 

Any thoughts

[MiNi Beast]

What are your stats my man? other than in your sig like what tire size and gears?

 

I have to be in 4low to climb any hill, but I have a stock 4.0-4.10 gears but running 37" tires so not enough gear to power ratio but that's my setup.

[hogelectra]

good idea

 

engine 2.5

transmission 4 speed

gears - I think 3.55

ties - 30x9.50

[MiNi Beast]

Don't no to much on the 2.5 as far a vacum and leaks, but know if you no have enough power to turn the tires then 4 hi sucks. So maybe the 2.5 is tired. :dunno:

[JeepcoMJ]

welcome to the 4 cylinder clan.

 

you have the classic "4 cylinder=no balls" disease.

 

options to fix?

 

deeper gears

smaller tires

upgrade motor.

 

 

those are your issues more likely than not. how is it on the streets doing similar activity? how does it perform on the road in normal situations?

[Eagle]

You have a 2.5L 4-speed. Unless you have re-geared, your axle ratio is only 3.55:1. The 2.5L is a good engine, but it's not a powerhouse, and it does NOT make low-end torque like the in-line 6 does. The 2.5L needs to be up above 3,000 RPM to be making much power or torque. That's tough on a clutch.

 

The reason it didn't feel like it had any power is simply that it doesn't have any power.

[hogelectra]

I was afraid that it might be the 4cyl was not enough. Well I finding myself a DANA 44 rear end to replace my DANA 35. So I'll add re-gearing to 4.56.

 

I assume replacing the gears requires special tools or experience?

[deziped]

Smash it to the floor & pop the clutch in ist gear. If it's more than a 3 % hill don't expect to shift to 2nd. Thats the nature of the 2.5, they gutless. The easy cure to alleviate this problem is use it as trading material to upgrade to a 4L MJ. It's usually less expensive than spending cash on gears or engine swaps.

[JeepcoMJ]

Smash it to the floor & pop the clutch in ist gear. If it's more than a 3 % hill don't expect to shift to 2nd. Thats the nature of the 2.5, they gutless. The easy cure to alleviate this problem is use it as trading material to upgrade to a 4L MJ. It's usually less expensive than spending cash on gears or engine swaps.

 

true enough, but you must remember, that his is an 86. unfortunately, unlike the 87+ 4 cylinder MJ's and XJ's, his 86 doesn't share the common 4.0 radiator support.

 

so, in order for him to do the swap he'd have to do some fabrication.

 

and at that point I would just suggest a camaro 3.4 motor...it's almost up there with a 4.0, a hell of alot better than a 2.5 liter, and it shares a common bellhousing with the 2.5 and 2.8 liters.

 

 

 

 

btw to the OP...you will be wanting 4.88's with that thing is my bet. if you want, we can work out something on a 5 speed trans from a 94 xj 4 cylinder.

[Pete M]

I assume replacing the gears requires special tools or experience?

 

Yup. :( It's one of the few things I would gladly leave in the hands of the pros.

[BLHTAZ]

I assume replacing the gears requires special tools or experience?

 

Yup. :( It's one of the few things I would gladly leave in the hands of the pros.

Absolkutely...gear jobs are NOT a DIY project.

[bigd44889]

were u located

the local 4x4 shop will do the gears for $800 out the door

labor and parts

as for the 2.5 off road is a 4 low area

i can run 4 high if i stay out of deep mud but mine is board 40 over and camed up

2.5

4 speed

31x10.5x15

stock gears been told should be 3:55

[hogelectra]

Lots of information and some bad choices maybe

 

First I must admit that the 4Low did get me where I needed to go with no issues - so I guess I could stay in the 3.55 gear range and just live in Low off road - maybe do some things to increase power like fan conversion to electric

 

At $800 (is that one axle or both) is more then I was hoping - I could buy a used Cherokee for parts with the right gears for that much and pickup an engine and transfer case as well

 

My long range plan (maybe in a couple of years - unless it breaks sooner) was to get a Cherokee for parts with the 4.0 engine, 5sp and better DANA and gears

 

Now that I know there is nothing wrong with my MJ maybe I'll address the other issue - more traction - Maybe I'll just put the Aussie in the front for now.

 

I remember in another track before buying you MJ make sure you know what your getting into - I didn't but still love the truck. Learning and doing all of this mechanical work is great for me - being a college professor in computers this is definitely outside my normal endeavor. But I must remember to pick the recently welded part up with the hand that has the glove on it. Some reason I can't seem to remember that for more then two weeks before I forget again.

 

Again thanks for everyone advice and help.

[BLHTAZ]

I would imagine that the $800 is for both. That would be a little high for one axle, but it's a great price to do both including parts :thumbsup:

 

You are correct that it would be less expensive to find a donor vehicle and get the axles from it with the gears you want. You could probably find 4.10's without a lot of trouble, but finding 4.56 will be a bit tough to do...although not impossible.

[bigd44889]

yes that is both and u would have new gears not used ones and if u want to up grade to an 8.8 he has them laying around to

http://onandoffroad4x4.com

i'm not affiliated with him but he does good work for a good price

[1974CJ5]

Learning and doing all of this mechanical work is great for me - being a college professor in computers this is definitely outside my normal endeavor.

:agree:

I think sometimes the guys on here are so car savvy they are burned out on the discovery part of the conversion processes! I am a graphic designer and all day I am looking at images, and working with computers and walking to printer, and putting up with latté drinkin' types. Don't get me wrong I love my work but, there is something about getting greasy and making things better than they were before and accomplishing things that are so foreign to me that really makes my weekend.

 

Now if I could just weld and fabricate! Don't mean to highjack, just glad that someone has the same perspective I have.

[Pete M]

I designed and built my bumpers/suspension/crossmembers/rollbar/rockerguards/etc mostly with just a 4.5" grinder and a drill. I only paid a pro to do the welding and the tube bending. Maybe in the future I'll get a nice welder.

I'm just sayin', don't let the lack of welder keep you from the fun of Jeep building. :thumbsup: Start small, build up your confidence and tool collection, and you'll be well on your way to tackling the tough stuff. :clapping:

[hogelectra]

If your a MJ owner you have to build your capability to handle problems and enhancement

 

That's what owning an MJ is all about - I bought one so I could finally use my 4 year old mig welder

[MiNi Beast]

If your a MJ owner you have to build your capability to handle problems and enhancement

 

That's what owning an MJ is all about - I bought one so I could finally use my 4 year old mig welder

 

 

You don't need a MJ for that... you can come over to my house and weld up all you want on my XJ I got plenty for you to do. :rotf:

[hogelectra]

For those in my area I have made that offer - just help me gas & wire costs

 

And be able to use a 4 1/2 angle grinder

[hogelectra]

Would a 2.8 with a 5 speed offer me much more power?

 

Would my transfer case match up?

 

Would need to move over wiring? What else?

 

Same year as mine but a 2wd

[Pete M]

The 2.8 is an inferior power plant.

[Eagle]

Would a 2.8 with a 5 speed offer me much more power?

 

Would my transfer case match up?

 

Would need to move over wiring? What else?

 

Same year as mine but a 2wd

The 2.5L and 2.8L share the same bell housing bolt pattern and use the same transmissions. On paper the 2.8L puts ot a bit more power, but in real life it is (as Pete wrote) an inferior engine. It is absolutely not worth the effort of replacing a 2.5L with the 2.8L. The 2.5 is an inherently superior engine, and can be tweaked to put out more power than the 2.8L.

[mvusse]

The 2.8 makes barely more HP, not enough of a difference to notice, hardly any more torque (again, not enough to be able to tell without a dyno) and uses twice as much gas doing it.

 

The only reason for people buying a new Jeep with that engine was that it was the cheapest engine option. I also believe it was discontinued in Jeep in 1987.

 

But since a 2.8 fits, a 3.4 out of a Camaro should also fit, and mounts to the same bellhousing. Same block, more power, fuel injected.

[JeepcoMJ]

it's very simple to drop a 3.4 liter in your truck, you'll just need a 4.0 liter fuel pump, a set of comanche 2.8 liter exhaust manifolds and y-pipe, 2.8 liter oil pan and timing cover, and a bit of wiring to lay it in.

 

you'd just run the 3.4 as a piggyback system to your 2.5 liter harness.