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Dieseling question

Discussion in 'Early CJ5 and CJ6 Tech' started by PierreDnepr, May 29, 2014.

  1. PierreDnepr

    PierreDnepr Member

    Hi,

    I search the forum in regards to dieseling because my F134 is starting to do this occasionally specially after a good long drive. The consensus was too hot, fast idle, carb too lean and timing.

    I did my carb with a vacuum gauge I was getting 18 but it was jumping a bit between 17.5-18 at idle (700-800 rpm) - it was ok when off idle. When I did the valve, I took the plug out and they were sooty... so I'm thinking... should I Seafoam the heads? Also, the timing was done with a timing light and its dead on spec at 5BTDC should I retarde it a bit due to engine wear? As for overheating, I didn't look at the thermostat so I may as well change it - what is the recommended temp setting for a F134 in Canada (25-28 degree C in summer and -15 C in Winter in my area)?

    One more thing - I change the oil and then took the jeep on its first long ride highway ride (120 km) and the rear main seal that was previously dropping a spoonful of oil was now dropping about 5 of them when I parked it. I gather that due to the hotter than usual oil temperature. Any hoot it looks like I'll be getting oil in my face soon enough. In the meantime did any of you use a product called "no leak" on a temporary basis??

    Thanks for your help.

    BTW- I am writing a PDF document with pictures based on the excellent video on UTUBE in regards to the valve adjustment - I'll post it as soon as I'm done.

    Pierre
     
  2. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Thermostat should be 165ºF type.

    A cause of dieseling can be the throttle not shutting completely or an intake air (vacuum) leak. Same idea as a fast idle situation. Carbon/burnt oil deposits in the combustion chambers or on the plugs may contribute, so they say.

    Is your PCV valve and system clean and functioning correctly? Possibly a leak in that might explain the oil loss and the dieseling. Just a wild guess.
     
  3. PierreDnepr

    PierreDnepr Member

    PCV valve is clean and operating properly - at least the little ball can be heard when sacking from side to side. A mechanic did a smoke test on my jeep about 3 months ago and no leak. I'll sea foam it fist to clean out the top end.

    I also did some investigating on the web in regards to the "no leak" product and I decided not to chance it. Some people reported sealing the rear main temporarily and softening all other "good" seals at the same time. I'm better off grabbing the bull by the horn and get it done properly.