1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

High altitude

Discussion in 'Early CJ5 and CJ6 Tech' started by navy67, Oct 8, 2006.

  1. navy67

    navy67 It's a Jeep thing!

    For someone thats been driving there Jeep in San Diego for the last 3 years, I don't think its been 500" above sea level for 5 years. This coming weekend I will be visiting the San Bernardino Mtns for some camping. My question is where we are camping is 7000-8000 feet, is there anythink I need to consider?
     
  2. scott milliner

    scott milliner Master Fabricator

    Take a coat. It's cold up there.R)

    I don't think you should have any problems. If it's running good down at 500ft then you should be ok.
     
  3. Vanguard

    Vanguard Take Off! Staff Member

    I've seen some jeeps need to be leaned out to run properly at the higher altitudes due to thinning air. My F-134 was fine, but we had to lean out a V-6 powered flatty and a 350 powered CJ-5 the last time.
     
  4. Patrick

    Patrick Super Moderator Staff Member

    Yup, probably run a tad rich..... Mine is a "tad" rich at 7500, but ran ok at Tellico (2500 or so IIRC).
     
  5. TigerShark

    TigerShark Sponsor

    I didn't make any changes to the 225 when we went to Colorado, while it ran a little rich, it was fine even at 10,000 feet.

    Jim
     
  6. barry

    barry Inquisitive Member

    I live in Big Bear and have no trouble with any of my Jeeps. Where are you going to camp? Maybe we can hook up.
     
  7. navy67

    navy67 It's a Jeep thing!

    Not sure yet. Maybe Crabflats. BTW do you know if I need a campfire permit?
     
  8. Project71-5

    Project71-5 BACON

    I'm at 7500 and rejetted down to a .048" jet. Runs great now....
     
  9. mpc

    mpc Member

    If you're at one of the camprounds you don't need a separate permit, it comes with your campsite.
     
  10. mtruckstuff

    mtruckstuff Held captive in Detroit..

    Rule of thumb....1 degree advance for each 1000 ft in elevation. You may experience some detonation and lack of power under load with sea level (or 500 Elev. settings). I'd advance about 4 degrees over base and adjust as I felt necessary.

    Paul
     
  11. panzer

    panzer Super Mod Staff Member

  12. tommy b

    tommy b Member

    :iagree:

    In the 60's I ran a Ford 1/2 Ton with a cabover camper on it out of Los Angeles. It ran fine until I took it up to 6000 ft. Then it just died, even in low gear, from lack of power. Of course, it had a big load (camper) and a small (292c.i.) engine, which made the problem worse. I wouldn't rejet unless you're going to be at altitude for a long time. If your vehicle is light (CJ5), you might not notice a lack of power. If you do, a little timing advance should solve the problem. Don't forget to retard the timing back to normal when you go back to sea level or the detonation could blow holes in the top of your pistons, depending on how much you had to advance it. FWIW.

    tommy b
     
  13. mtruckstuff

    mtruckstuff Held captive in Detroit..

    We lived above Fort Collins for 6 years at about 7500 ft. Even the 2500 ft difference was noticeable. I ended up putting an MSD unit with a timing control on my '82 Scrambler to make it easier, because I had to make trips into town a couple times a week.
    Paul
     
  14. Project71-5

    Project71-5 BACON

    Right now my timing is the same as it was at 500', roughly 4-6*. Seems to run great, I do get some slight detonation but that I really can't tell if its just bad gas, not enought rpms, etc... Think that advancing it a few degrees would make a noticeable difference?
     
  15. tommy b

    tommy b Member

    Try it. You might be surprised. It's easy enough to turn the dizzy back if you go too far.

    tommy b