NEWS PARTS JEEP & 4x4 ATV & UTV

Milage Upgrades?

514 Views 19 Replies 4 Participants Last post by CJDave, Feb 24, 2000

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Discussion Starter · Feb 22, 2000

Hey folks. I am rebuilding my 87 258. Gas in BC costs me 65.9 cents a litre and my Jeep swallows a lot of it. I am putting in an RV cam with the rebuild, so what are any other (fairly inexpensive) upgrades to get more milage out of my Jeep? Thanks again

1987 YJ Laredo
Rylan D.

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Discussion Starter · #2 · Feb 22, 2000

what kind of milage were you getting? i can handle metric! i dont have an answer to a gas saving device other than the obvious tune up and carb adjust. good luck on the rebuild!
steve

291

· #3 · Feb 22, 2000

I have seen a wheel alignment / balance / pressure check add 1mpg, which is about .425 Km/Liter (if that's the way y'all do your gas mileage?)

/wwwthreads_images/icons/cool.gif Big Ed
'88 YJ, 4" susp,3" body,33's,283 Chevy V8,TH350,4.11's,D30,D35c

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G

Discussion Starter · #4 · Feb 22, 2000

It's a Jeep not too much you can do. Keeping it tuned up is about the best you can do aside from looking at tires and gears. What ever you modify for better or worse, something else will either benefit or suffer. I've heard K&N air filters can add some mpg as well. Watch the weight of your foot and keep an eye on your shift points if you have a std trans, that might help a bit too. Let's see, what else can we take a stab at...wind resistance, top, no-top, doors, no doors,etc. that might make a slight difference as well. The guys in pickup trucks put their gate down for less wind drag. How about lighter rims? Don't worry about it too much, it takes away from the fun of having a jeep! Besides, if you didn't have to stop and get gas, you wouldn't be able to have an excuse for buying lottery tickets, news paper, cokes, beer, beef jerky, chewing gum, breakfast tacos, potato logs, ice, or any other impulse items.

G

Discussion Starter · #5 · Feb 22, 2000

Having rebuilt a couple of 258's...there is a lot you can do to improve the horsepower...but horsepower means more gas. As for the engine, there is not much mechanicaly you can do to improve gas mileage. About the only sure fire method is to go with the Mopar FI setup. If this is more bucks than you want to spend, then going with a Weber (provided Canada does not do smog inspections) and with the HEI dist. Other gains can be made by going with synth oils in the transmission, transfer case and diff. It will really make a difference in the winter time.....which for you is a good % of the time.

Realistly, you can expect about 15-17 MPG (imperial gallon)....I have heard it hit 18-20 with the Mopar FI....

One side not on your rebuild...go back and do a search on some of the old posts...at least 3 months back. We had several threads going about mods to the 258.

Good Luck

John......southern CA
84CJ7, 3"lift, 32"BFG, 4.10's, ARB Locker, Solid Axle's, Durabak

034

· #6 · Feb 22, 2000

I think synthetic fluids in your engine/tranny/t-case and differentials will get you a bit of mpg...

Tim
"The_Sandman_454"
/wwwthreads_images/icons/cool.gif '79 Suburban 4x4 454, 6" lift, 35x12.5s & '85 GMC S15 4x4

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13337

· #7 · Feb 22, 2000

Fuel Injection will add a considerable amount of milage to the old Jeep if you use the correct cam to work with FI.
Bringing your ignition up to snuff will insure you are burning all of that liquid gold that's going into the tank.

Mounting a vacuum gauge in the cockpit where you can see it will teach you how to drive in a hurry!
The higher the vacuum reading, the better the fuel economy you are getting...
Watching the gauge while you are driving, and shifting, and pulling out will be a real eye opener!!!
It's cheap, and it's very effective!

If Chris Columbus "Discovered" America (with 25 million already here), Can I Go "Discover" Florida?

G

Discussion Starter · #8 · Feb 22, 2000

I've got a vacuum gauge and if you keep it over 10 or so you will notice an improvement in the mileage...it basiclly teaches you to be a little lighter on the pedal than you normally would

80 CJ-7 Laredo 304v8 TF999 3.73's BFG M/T's

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Discussion Starter · #9 · Feb 23, 2000

My experience with a cagle fuel reg has gotten me upto 19 set at 2.5 and still runs great. I think is saves on the sloshing. Ken

http://members.home.net/nosweat/

G

Discussion Starter · #10 · Feb 23, 2000

On the fuel regulator idea, what should it be set at? I had a CJ5 with a V6 a long time ago and we had a carb flooding problem, after a couple of kits we determined we needed a fuel reg to cut down on the gas flow. When we did it,it was trial and error. Should there be a min/max flow setting?

G

Discussion Starter · #11 · Feb 23, 2000

Where would I hook up the vacuum gauge's sending unit?

1987 YJ Laredo
Rylan D.

13337

· #12 · Feb 24, 2000

It is a cheap vacuum hose to the gauge. About $0.10 a foot.
Hook it to any of the unused vacuum ports on the intake manifold or carb base plate.
Don't hook it in with the PCV line.
Cheap, easy to hook up, and will teach you a lot.
Use it to set your idle mixture if you don't live in an emissions testing area, that might help you gain a few tenths of a mile to the gallon...

If Chris Columbus "Discovered" America (with 25 million already here), Can I Go "Discover" Florida?

G

Discussion Starter · #13 · Feb 24, 2000

what exactly is a vacum gauge? and where does it plug in to? if it is the carb
will it work if u have a after market carb? can u use the gauge other reasons if so what?

13337

· #14 · Feb 24, 2000

A 'Vacuum' gauge is a device that samples a low pressure area, and gives you a reading on a scale (gauge face) of that low pressure area.

In the hands of someone in the know, a vacuum gauge will tell you if you have bad valves, and in what head, or even what part of the head, It can set your idle fuel mixture, it will tune your carb, it can tell if you have vacuum leaks, and where they are, it can tell if you cam, lifters, rocker arms, or valve springs have gone bad. It can be used to test fuel pressure, fuel volume, and tune transmission shift points.

It is mandatory for tuning any carb, ignition system with vacuum advance, transmission with vacuum input, and diagnosing most fuel injection problems.

Most of the younger guys prefer to skip over the basics of the old school in favor of the Strap-On sex toy and engine analyser. They have no idea of how the engine works, or how it's supposed to work, so a set of basic tools won't do them any good anyway. If it doesn't throw a trouble code, have a flashing light and wave a red flag, they are lost...

There are only about a dozen laws of nature that allow an internal combustion engine to operate, and once you really understand them, the rest is a piece of cake, (but I prefer pecan pie!).
I don't know how many trade school and collage educated kids we go through here that can't tell you what basic principal a common bolt works off of, or why gear lube seeps out of cracks above the liquid line.
They can recite the most complex test procedures in the world, but can't figure out why putting a low restriction air cleaner on their DZMB-5000 Super ZX whatever motorcycle made it run like crap... Or how to fix it...

When you ask about the 'Hall effect', or 'Venturi effect', or 'Load Sheer', you get a blank look, and then find out that in two to four years in collage or trade school the principals were never discussed, or at least not enough the kids understand them...

But I digress...
Get a good vacuum AND pressure gauge. Sears used to make a pretty decent one for under $30. Large face, easy to read markings, real glass lens, metal case, and adaptors.

If Chris Columbus "Discovered" America (with 25 million already here), Can I Go "Discover" Florida?

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G

Discussion Starter · #15 · Feb 24, 2000

can the vaccum gauge be spliced into the vaccum advance hose? Also, how can I read my gauge to see how my carb is set?

1987 YJ Laredo
Rylan D.

G

Discussion Starter · #16 · Feb 24, 2000

What engine speeds will you travel at most? Consider that, your gearing and tire size, use synthetic fluids throughout, although wait until your engine is broken in before using syn, and consider building for lowend torque rather than horsepower. I'm no expert but it has worked for me in the past. Good luck.

CJDave

· #17 · Feb 24, 2000

4

/wwwthreads_images/icons/tongue.gif Rylan.....if your engine is like most, there are a few taps into the log section of the intake manifold for full-vacuum items like shifters and so forth. Those are the ports you want to use to feed the vacuum gauge. You can get a "Street Tee" in brass at the auto parts and the little brass hose barb fitting for the hose that goes to the gauge. That setup should get you the full vacuum outlet that you need. You can't use spark advance vacuum for this job. Try to install the gauge in a place where you can see it without taking your attention away from the road. And try not to run over or into anything while you are driving the Jeep and watching the "Tromp Meter".(vacuum gauge)./wwwthreads_images/icons/crazy.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.

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13337

· #18 · Feb 24, 2000

Do NOT splice into the vacuum advance line.
That is 'Ported' vacuum from higher up on the carb if everything is hooked up correctly.
Any port on the base plate of the carb, and any of the intake manifold ports except the PCV.

If Chris Columbus "Discovered" America (with 25 million already here), Can I Go "Discover" Florida?

G

Discussion Starter · #19 · Feb 24, 2000

On my intake, there is a few tapped holes where sensors go into. Is there a fitting that I can buy that will just transorm this into a vaccum port? The CTO valve has about 5 lines coming out of it, but I just want to do away with that. The only other vaccum is for the heater actuator that goes through the firewall.

1987 YJ Laredo
Rylan D.

CJDave

· #20 · Feb 24, 2000

4

/wwwthreads_images/icons/tongue.gif Hmmmm...... My most experienced moonguy; actually he is my Chief of Repair; says that if it were him, he would buy a plastic "tee" at Joe's Auto Parts and pop the tee in the heater actuator line./wwwthreads_images/icons/wink.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.

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