the lack of fwy speed

[Whynotcj7]

Can I get some advice on how I can get my 84 cj7 on the freeway in a manner in which the big 16 wheelers aren't passing me? Is it the gearing, the motor, what? I got the jeep from a English couple who didn't know too much about what was done to the jeep when they bought it. Honestly, can someone give me some specs by these pictures, cuz I have no clue.

 

[steady.foot]

I noticed that you have an aftermarket weber carburator. Is it hooked up right? Is the cable adjusted so it gives you all the throttle that it has? are the jets adjusted right? Do have a tachometer? What is it reading when your going as fast as it will go? Maybe your gearing is too low but even with 4.11 gears i would imagine you could travel at highway speeds. And as far as those big trucks go, They've got a lot more power now days than they used to. They can maintain highway speeds plus easier than most cars. And, they've got 18 wheels not 16. How would you like to kick all of them to make sure one is not flat before you can start work in the morning.

 

[TLCJ5]

What transmission do you have? A 4spd?5spd?auto? Also what size tires? They look like 31"s ,but it's hard to tell from a picture. What speed are you topping out at & is the engine whinning or just loping along? As Steadyfoot said you have a Webber carb....it is possible that your 4cyl is over-carbed.

 

[TerryMason]

I had an 85 cj7 with the 6 cylinder and I was constantly getting passed on the highway, especially when it was hilly.

Let us know more info about your jeep like
Top speed (if you know it)
What rpms are you running on the highway
Tire size.

It very well could be that your jeep isn't tuned properly, however a 26 year old jeep is not going to be a speed demon.

Sent from my DROID2 using the Jeepz.com app

 

[Poop3000]

4.0 head swap is a popular upgrade, as is MPI fuel injection. depending on what you're willing to spend.

 

[TerryMason]

4.0 head swap is a popular upgrade, as is MPI fuel injection. depending on what you're willing to spend.

The picture's kind of blurry, but I think that's a four banger.

 

[superj]

I think it is also. I would say make sure carb is set up right and upgrade the gears if you got bigger tires

 

[Chip01TJ]

I think if you take a moment to appreciate the ability your Jeep has off road it will be easier to forgive it for not performing on the freeway.

 

[Gennybro]

I think if you take a moment to appreciate the ability your Jeep has off road it will be easier to forgive it for not performing on the freeway.

Yup, the machine was not intended for asphalt,just feed it mud,rocks rivers and gullys.

 

[steady.foot]

In the picture, the valve cover looks like a 6 cylinder(The angle of the picture is decieving) but if you look at the distributor it looks like there aren't very many spark plug wires. And it looks like one or more may be missing. The U in the serial number indicates that it is a 150 four cylinder. Can we get another picture of the side of the engine and the distributor. Does anyone else see the empty wire socket on the distributor cap?

 

[Poop3000]

The picture's kind of blurry, but I think that's a four banger.

absolutely. my bad. my brain is also blurry, after a day with the youngin'.

 

[Poop3000]

and yeah, at best tune on that setup, you'll still have issues keeping up with tractor trailers a lot of places. not saying there aren't things that could be fixed, but not keeping up at highway speeds on that four-banger is not necessarily a sign of something not working as designed.

 

[Whynotcj7]

My top speed is at 60, and i dont have an rpm gauge. It Doesn't sound like tHe 4 cylinder motOr is being over worked when I'm on the fwy. It's a 5 speed and i notice 4th and 5th gear feels the same when I step on the gas. No speed increase when I'm in 5th gear. As for the carb, I havent touched or checked it, so I will soon. I'll make sure its properly adjusted. Hopefully that will help. I'm not trying to race the tractor, just need to be able to get/go places on time. I thought feeding it mud would help, but all the mud that flew inside the jeep just weighed me down more. Yes, I played in a little mud with the top down, doors off.... Sigh, I have so much to learn... But Damn that was thrilling! Thanks again for helping everyone. Once I get her strong, I'm going places!

 

[PoliceMonkey161]

Hello,
I'm new to this forum, but not new to Weber carbs. I had similar issues. Start simple! As the other gent recommended, check for free linkage/ full travel. After that, the number 1 problem is vacuum leaks. You also need to regulate the fuel pressure to 4psi. Lastly, rebuild after installing a quality tachometer, pay close attention to the float level.

Sounds like your secondaries are not opening. If you need more help, please get in touch with me. I have all sorts of references for you to use. Don't give up on that Weber. Once you understand them, there is nothing like them.

 

[superj]

And those older 4bangers really have a hard time on the highway anyways. I had a 4 cylinder commanche a number of years back and it did ok on the highway till I put 31's on it. Then that poor truck was done at 65ish and 14mpg was Max. It had the fuel injected 4 cylinder and a three inch lift. Good truck but no power and bad gas mileage.

 

[Whynotcj7]

thanks steady.foot, here is a better picture of the side of the engine. hopefully you can tell me more about it. I'm running on tires sized 32x11.5x15.

In the picture, the valve cover looks like a 6 cylinder(The angle of the picture is decieving) but if you look at the distributor it looks like there aren't very many spark plug wires. And it looks like one or more may be missing. The U in the serial number indicates that it is a 150 four cylinder. Can we get another picture of the side of the engine and the distributor. Does anyone else see the empty wire socket on the distributor cap?

 

[steady.foot]

Yup thats the 4 banger. Funny how it looked longer in the other picture. Even tho all 4 spark plug wires look to be in place, It looks like there's an empty socket on the distributor cap. I've never had a 4 cylinder so i'm not sure if it's what i think i'm seeing.:shades: Not sure how high an rpm that that engine runs well at but maybe with the larger tires a lower set of gears might help with more power and keep up with traffic too. The 4 cylinder guys will have to chime in on that. Keep it tuned up to the best that you can. You're working with a small engine.

 

[Bounty__Hunter]

Most of it is likely your axle gear ratio, too tall of gears for the oversized tires and undersized engine. Determine what your axle gear ratio is and we'll go from there. Look for metal tags beneath a diff cover bolt and post the numbers. If no tags, pull a diff cover and look for the numbers on the side of the ring gear.

 

[Jester32]

Or jack rear wheels up and count how many times you have to turn the driveshaft to get one rotation of the tired.

 

[azyjjk]

When I look at the distributor cap I see 5 wires so to me nothing is missing.