1981 Jeep CJ7 lose power in 4th gear

Tiny
JASON11673
  • MEMBER
  • 1981 JEEP CJ7
  • 6 CYL
  • 4WD
  • MANUAL
  • 21,000 MILES
Engine runs fine in 1-3 gears. When I shift to 4th and get to my max speed as of now (55) engine has no pickup and loses power. Shift down to 3rd and power shows up again, but at high rpm's. Things I have done and found. Changed oil and filter. Changed fuel filter. Put new air cleaner on. Checked timing. Put new fuel in. Pulled valve cover off and found 2 push rods off replaced and put new valve cover gasket on. Also shifter has 2h-4h-n-4l just got jeep and cant find anything to tell me where the 4x4 shifter should be at highway driving. I cant put it into 2H. Is that where it needs to be? Please help!
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Monday, November 8th, 2010 AT 4:08 PM

9 Replies

Tiny
CJ MEDEVAC
  • EXPERT
See my profile,

Jason this could be involved, I want you to sorta "SWIM" around at this Link, see if there is something that might help.

I can see by your mileage, your Jeep is finally about to get "Broke In"!

I know this may not completely be your deal, but there is much good info here, if you can understand my "rambling"

http://www.2carpros.com/forum/1984-jeep-cj7-84-cj-7-stalls-when-it-idols-vt522698.html?highlight=

Return with questions to this location at "reply to question"

I will help you all I can...please bear with me!.... Having some Family issues now, This is my Hobby, Really try what you can, that I mention, in the other posts, that maybe you overlooked.....We will get you going, hang with me!

Preventative Maintenance (stuff you should do regularly) is important..... Found in Repair manuals.......YOU MUST HAVE AT LEAST ONE...I HAVE MANY, JUST FOR MY JEEPS ALONE!

If you have a Dana 300 transfer case---check your fluid level....Do you have a repair manual?

Dana 300 has 4 positions...Closest rear is 4 HIGH, then 2 HIGH, then NEUTRAL, all the way forward is 4 LOW.....You sometimes have to rock your Jeep...FWD-REV over and over while attempting to push Transfer Case Stick.....Insure your Transfer Case linkage is lubricated to Specs

You explain well in detail---do not leave anything out that I should know!

Did you watch all push rod operation, while running, while the cover was removed, and you had 'em all installed?

Your Turn

The Medic
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Monday, November 8th, 2010 AT 8:59 PM
Tiny
JASON11673
  • MEMBER


http://www.2carpros.com/forum/automotive_pictures/590543_afghan_pics_017_1.jpg


http://www.2carpros.com/forum/automotive_pictures/590543_afghan_pics_018_1.jpg



http://www.2carpros.com/forum/automotive_pictures/590543_afghan_pics_019_1.jpg



http://www.2carpros.com/forum/automotive_pictures/590543_afghan_pics_020_1.jpg



I had a friend come over that used to own a jeep and we figured out the tranfer position, previous owner must have put on a different knob. but that didn't fix the problem. I did run check it when i put the push rods on and all is working fine, boy did it throw radiator fluid.lol. friend told me that the cat converter might be stopped up. what do you think? thank you for replying and i know this thing will run just hope it doesn't cost a fortune to get it there. I sent some pics of the engine. I dont think it is the original engine due to so much not being hooked up and the valve cover it has is not the one for that engine.
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Tuesday, November 9th, 2010 AT 9:54 AM
Tiny
CJ MEDEVAC
  • EXPERT
Are you in one of those Emission tested places?

'Round here....not yet anyway!

Some of the smaller Ma and Pop type shops say they cannot remove them, So once I Hack 'Em off (on non-computer OBD controlled rigs) CJs are in the Hack 'Em Off Catagory, They will straight pipe them!.......Personally, I cannot see keeping something on my rig that could affect driving and DAMAGE MY ENGINE!

When/ if they should check 'em here....they might "Grandfather In" stuff already done......Or (I hope not) Put it back to specs for that year........Needless to say, I will CHEAT as long as I can!

Usually take them to them with a Header Installed, needing the rest of the exaust system.......Might check in advance! Tell 'em somebody stole it to get the scrap value!

To VERIFY your thoughtsIf its YOUR CONVERTER---It will demonstrate the same SYMPTOMS (Holding Back, not wanting to go) at a lower gear, at maybe a higher RPM

Is my other crap aiding you in getting your Jeep to SIMPLE COMBUSTION ENGINE SPECS?

All of that extra Vacuum lines and the wiring to the VAC CRAP....does no more than adjust your Carbs Metering, This IS NOT FUEL INJECTION!!!.....Still using CARBUREATION(sp) from the 1910s! usually if you haven't rebuilt or replaced a carb that old---the METERING is not working anyway....Most of the time, over the years, "JIMBOB" has modified stuff, or failed in maintaining......You have gained no efficiency!.......Cut your losses, simplify your engine, replace with a 1979 BBD (last year, before crap started)...............Then you can use only needed vacuum lines, Bundle up the useless wiring (tape it away on the Jeep) Just in case they make you put it back!....Take pics of what you do, if you feel like you will forget where the stuff went to.

Come Back?

The Medic

See what you could look like?......Yours does have a aftermarket (better) valvecover.....My '77 had a Metal cover to begin with, why did they change to worse????!!!


http://www.2carpros.com/forum/automotive_pictures/411289_100_0327_1.jpg



http://www.2carpros.com/forum/automotive_pictures/411289_100_0328_1.jpg

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Tuesday, November 9th, 2010 AT 10:59 AM
Tiny
JASON11673
  • MEMBER
Looked underneath and it has no cat converter. So that isn't the problem. New problem. Went to the store just a few minutes agao and whole damn thing started jumping lit it was a jack rabbit. Had to stop before I flew off the raod. Engine died. Was able to reastart though and make it home with no other problem. Could this be related. I do not live in one of those regulated states, at least I dont think so. I live in Louisiana and even if I will just play ignorant if the situation ever arrises. Like your jeep!
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Tuesday, November 9th, 2010 AT 12:31 PM
Tiny
CJ MEDEVAC
  • EXPERT
Roger, Thanks for the Jeep Compliment!

I'm back at the Hospital (my shift) while Pap, hopefully recovers enough to go home, Laptopping right now---keep me busy with your Jeep, Please!

I'm sure you are having related issues.

Do you have tune-up tools? Know your way around under the hood?

Have you tried any reconfiguring and capping off unnecessary lines, as in the "STALLS WHEN HOT" (or something like that) CJ 7 w/14 responses. On down the list, in the CJ 7 forum

If you would---cap off all I show unnecessary. Keep the 3 or so, I show as critical. This will eliminate A LOT OF POSSIBLE VACUUM LEAKS!

How is/ did it idle?

DETAIL WITH ALL, IS BENEFICIAL

Are you ready to start "GUT RIPPING". Is what others say I do to theirs!

Your Turn

The Medic
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Tuesday, November 9th, 2010 AT 1:15 PM
Tiny
JASON11673
  • MEMBER
I know how it is in the hospital. I spent a week there when my dad was diagnosed with pancratic cance. Thanfully they got it and he is doing well. Hope your dad gets to go home soon. I know as they say, enough to keep a good car running, but am very mechanicly inclined. I am a small engine mechanic and can doo the small stuff. I do not have tune up tool and dont even know what they are. I will go cap all those lines now. Wife just got home so might take some time, but I will get back with you as soon as I can. Once again thanks.
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Tuesday, November 9th, 2010 AT 2:09 PM
Tiny
CJ MEDEVAC
  • EXPERT
I am assuming your bucking and jumping ride was the engine? Please let me know if you had Grinding, Metal to metal sounds (I hope you meant it was just engine out of calibration bucking etc!)........Do, as I told the other guy, tighten your carb body screws and also the nuts holding it to the carb to the intake.........might as well "torque" the intake/ exaust bolts and studs that holds both onto the engine head too.

We must sorta systematically get all vacuum leak possibilities...out of the equation

If you would, to make it EZer, for me to PONDER (others reading this too!).....maybe numerically list (Short and Sweet) Your Findings/ tests/ Symptoms.......Maybe do one to up to this point now.......EXAMPLE

1) Have a Chiltons repair manual----I can now understand some of the items you are telling me to mess with!

2) I now have the Distributor/ power brake booster/ and the other 2 lines hooked up----all else is capped off----I HAVE NO DOUBT THEY ARE HOOKED UP IDENTICAL TO THE OTHER POST...."Explodes in Garage" page 2, 3rd/4th/and 5th pic......I do not uderstand paragraph 12,345...below pic of Rabid Monkey, explain?

3) I know, I really need tune up devices, in order to do anything else to my rig, otherwise I will be pizzing in the wind! I have this that this that.....will they work?

I really think you can put the important stuff in, like that, the discussions just continue in paragraph form, like now, EXAMPLE: I do not understand your Military lingo, I have been confused from the beginning....your jumping all over the place is pizzing me off, I would kick your donkey if I had a closer address to find you!

Do you have a near-by "Harbor Freight"? This KIT is under $40 (cool thing is, everything is compact and all stored in one location, sorta cheaper than purchasing everything separately),.............for now, this, and small your Regular small engine tooling, 0-150lbs (click type for now) torque wrench (available at H.F. too)..........a Repair Manual ($30) WILL HAVE YOU FIXIN 90% of the Entire Jeep!(available at popular auto parts stores).......Once you start "Jeep CJ Fixin", Things are very simple compared to these newer cars!


http://www.2carpros.com/forum/automotive_pictures/411289_HARBOR_FREIGHT_1.jpg



"WILLY" my '46 Willys--- Built from the Ground up--by myself!........Basically, He's a Big Lawn Mower or a Older Small Garden Tractor!


http://www.2carpros.com/forum/automotive_pictures/411289_YOU_WISH_YOU_HAD_A_REAL_JEEP_006_1.jpg



Can you comply with the Tune Up tooling?.....Vacuum Gauge, Dwell/Tach, Timing light,...........Even a Digital Cheap Voltmeter ($3-$5 at H.F.)...............You will soon be the "Sought After" Neighborhood Mechanic Dude, after 2 hours of Hands On!

You have 2 PMs (private messages) at the index waiting on you!!!!!!!!!!!!!

After all of this....You'll probably see me on T.V. as the Harbor Freight "Spokes-Model"......Yeah, I you don't have confidence in yourself, who will???!!

The Medic......AKA, 1st/ 75th Ranger Battalions' "The Battalion Stallion".............I still Hold this title, even to this day!.......Along with being a "Self Certified Rear Lawn Automotive Technician" (SCRLAT)
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Tuesday, November 9th, 2010 AT 3:25 PM
Tiny
JASON11673
  • MEMBER
Wife came home while putting vaccume hoses the way you show in you other post and she is wanting to spend time with me a for I am on vacation and have already spent three days on this jeep and the later it gets the more beer I drink. So might take morrow off and spend with her. Thanks for your help and will be back with ou in a day or two. Once again I hope your dad is doing fine.
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Tuesday, November 9th, 2010 AT 6:21 PM
Tiny
CJ MEDEVAC
  • EXPERT
Roger,

I appreciate you "complying" with my requests on Narrowing down your problem.

I get few responses. Never know if I helped a lot of the time. Maybe they think I'm Stupid. Regardless, my Jeeps' run well! I know what to do in troubled times!

You will not be sorry, this will make your Baby, very happy in the end. Referring to your Jeep. It will drive a lot better, even if we locate something else causing this issue, along the way.

Sounds as though He ( a strong, manly pronoun, for a "Manly Vehicle". Please don't give HIM a Sissy name) Has been Neglected for some time!

Pap is doing better, . Than before. Having a Blood clot filter installed tomorrow, so they can take him off of blood thinners.

I see you haven't picked up your PMs (Private Messages) I can tell, when they go into my "Sent Box"

You will see where to click for them, beside "View Your Posts"---"Search"--"Register"--"Log Out"

Keep up the work----let me know when "Mama" gets back from Harbor Freight with your tools

Are you CONFIDENT in doing all of this? DEFINITELY ANSWER THIS ONE!

Sometimes I make the mistake, in thinking people have already done the Basic Checking of stuff

Before we go on, Does your Jeep run decent, from the beginning, and then start messing up? The reason I'm asking this now is, if its always bucking and such. Have you VERIFIED your FIRING ORDER IS CORRECT?

Do you know how to do this? I will help you with that, NOW, This is very important, and if this is your WHOLE PROBLEM, I will still talk you thru the rest, if you want to continue!

I will Talk you thru what you have. And what you should have. IF YOU ARE UNSURE. IF YOU ARE CONFIDENT, 100% SURE THAT IT'S RIGHT, I WILL NOT TAKE THE TIME TO RUN THRU IT (this could also account for bent push rods)

Not only could the wires be on the wrong positions, but the distributor could be installed (incorrectly) as not to allow for ENOUGH "SPINNAGE" to time it correctly (bottoms out before it gets to the marks), or the UNIT ITSELF, be worn to the point of not turning (in a smooth circle) and jumping about erratically!

I'm gonna re-read your stuff and make a list of what you have done thus far. Then make a list of whats next

How is my "RAMBLING" so far, in this and other posts. Are you able to Keep up with/ "Decipher" my "CRUDE" Explanations?

You might also review my answering in this post, I have sorta went back and edited here and there!

I'm SORRY.I know my stuff, I could Show you much EZer.I do not do this on a Daily Basis.I have Fixed Every Jeep in my Area, so I'm sorta sitting around like the "Maytag Man"!

Happy Vacation!---Stay warm with Baby #2.(That would be # 3 in my case!)

The Medic
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Wednesday, November 10th, 2010 AT 12:31 AM

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