1976 Jeep DJ5 emissions

Tiny
MBALEDA
  • MEMBER
  • 1976 JEEP DJ5
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 10,000 MILES
This mail jeep will not pass emission at idle, loaded tests well below requirements. Idle is at 2x limits. We have replaced distributor, plugs, fuel pump, EGR, wires, every vacuum line, set and reset timing. Changed out all filters, rebuilt carb, pretty much all I can think of. It does have a small catalytic converter, which I believe was added after it became a private car. Would a bigger, better converter help? Any suggestions? Thank You.
Mike
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Monday, October 18th, 2010 AT 1:06 PM

6 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
How many miles are on it? Has compression been checked? What readings are failing it?

Let me know.

Joe
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Monday, October 18th, 2010 AT 1:46 PM
Tiny
MBALEDA
  • MEMBER
100000 miles or so. Compression checked out, within 1% of each other. The car passes both hydrocarbons and CO loaded, but fails both at idle. Both about 2x the limit for Arizona. HC reads 495, while CO reads 5.89. I don't remember the compression test reading offhand, but I do recall just over 100 in all cylinders, so did nothing with the valves or rings at this point. It has electronic ignition, replaced it to be safe. Thanks
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Monday, October 18th, 2010 AT 2:40 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
It sounds like you have done everything, and although the compression sounds a little low, it's isn't bad. The last thing you could try is a new converter. Keep in mind, the vehicle wasn't designed to have one, but if you get a universal one, it may help.

One last question, for the reading to be that high, I would think the engine is running rich. Have you tried everything as far as adjusting the carb?
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Monday, October 18th, 2010 AT 8:22 PM
Tiny
CJ MEDEVAC
  • EXPERT
Sorta Late here,

Whatta bout Tweaking the mixture screws "leaner" or upping the Idle on that 258 or 232 up from 6-700 up to 800 or 850. This is probably a YF or BBD Carb, What about PCV? Replace/clean/ increase to a larger size

Maybe that would allow more combustion air at Idle.

Just a thought

The Medic
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Thursday, November 18th, 2010 AT 2:01 AM
Tiny
MBALEDA
  • MEMBER
Thanks CJ Medevac. That is exactly what I did, except for checking PCV. It did pass, but just barely. I readjusted it so it would run correctly for her. But I would still like to solve the real problem. I will try the PCV and let you know. Thanks, Mike
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Thursday, November 18th, 2010 AT 1:19 PM
Tiny
CJ MEDEVAC
  • EXPERT
I have '77 CJ 5 258, used to be a 1bbl, now after many years of upgrading its flourished into a rebuilt engine (Several years back) and more. Built now to '79 specs w/ 2 bbl cam, and now a Holley 4bbl 390 CFM.

When I had 1st got him ("Mr. Jeep") Had a YF 1bbl, the entrance of the PCV steel line into the intake was MEGA RESTRICTED with grey hard carbon (almost looked like it was metal!)---I took apart and cleaned everything in that vicinity.

Now that the air was coming thru good, I had to re-tweak my carb, cause mix was wrong at idle--from previous Tweak to make it idle.I do not know what you do with your Jeep, But I LOVE BOTH OF MINE! If you investigate CJ 5 & CJ 7 Forums (if you still can, with this new Site Retrofit) See a CJ 7 from months ago, Its something like this, "1985 CJ 7 STALLS WHEN HOT"---If you can pick thru and De-cypher my Country-boy fixin' it might aid you in some way---maybe even get idle speed back to normal and "Off the Mains"--and back on the Idle Circuit again----should you be on them now. If you hit my username link and reply back with a Message there, that stuff may help some with other stuff too!

Here if you ever need me

The Medic
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Thursday, November 18th, 2010 AT 10:12 PM

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