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Post by Scoutpilot on Nov 8, 2019 10:47:56 GMT -5
F4-134
Idling nicely at 700RPM
Vacuum at 20hG
Dwell at 40º
Since my motors idle a lot, I decided to squirt some MMO down the carb to break up some of the carbon buildups.
Rev to about 2500.
Hear a ping.
Vacuum suddenly drops to 15, steady.
The motor is now idling rough as if it dropped a cylinder.
Adjustment won't bring vacuum back up.
While idling, I start pulling spark plug wires.
#1. Idle drops a bit then perks back up with reconnection.
#2. Idle drops a bit then perks back up with reconnection.
#3. Motor quits immediately. Reconnect, restart.
#4. Motor quits immediately.
Water temp 170º
Oil pressure steady at 35PSI.
Broken valve spring??
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gmcjr
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Post by gmcjr on Nov 8, 2019 12:28:07 GMT -5
Or maybe got luck and a piece of carbon or something under a valve?
Compression test?
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Post by Scoutpilot on Nov 8, 2019 12:42:06 GMT -5
Tomorrow I’ll run a compression test...
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Deleted
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Post by Deleted on Nov 8, 2019 12:44:47 GMT -5
Should be labeled “Murphy Mystery Oil” 😂😂😂 I would go with the carbon deposit lodged in the valve seat, or you lost a butterfly scar and bent a valve 😮 Shit happens, mostly to us 😮
Lee😉
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Post by brucew on Nov 8, 2019 13:00:27 GMT -5
I’d say the problem is in #1 or 2, but I’m sure you already know that. I agree a chunk of carbon (hopefully) or some other foreign object could be holding a valve open. An exhaust valve not closing will disable that cylinder, but an intake not closing will upset other cylinders on the same intake runner. If #2 intake was hanging open it would blow air back into the manifold just as #1 is trying to inhale. B-dubya
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oilleaker1
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Post by oilleaker1 on Nov 8, 2019 18:19:02 GMT -5
Old mechanic trick to burn out the carbon is to hang a soup can over the carb with the engine running at a strong idle and up to operating temperature. Poke a small hole in the can bottom so it drips water slowly into the running engine.
Marvel Mystery oil would dislodge carbon also. Essential Lube another. Water doesn't smoke or foul plugs like oil does.
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Post by rickg on Nov 8, 2019 20:25:12 GMT -5
Just like I advised the Cap'n.. Put a solex on it.. don't forget to whine about carb leakage before you throw bandaid money at a regulator.. Oh and replace the condenser.. Hope this helps.. Shit-Sorry Boss..  |
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Post by rickg on Nov 8, 2019 20:27:41 GMT -5
No shit tho-the Professor, Cap'n, BW and Oilly spoke good advice.. Me, i'm just clownin..
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Post by m38mike on Nov 9, 2019 4:55:31 GMT -5
Just like I advised the Cap'n.. Put a solex on it.. don't forget to whine about carb leakage before you throw bandaid money at a regulator.. Oh and replace the condenser.. Hope this helps.. Shit-Sorry Boss.. Muley, you funny guy.  |
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Post by rickg on Nov 11, 2019 12:44:09 GMT -5
Any updates Boss? Wouldn't it be cool to have dedicated L and F134s on stands in the shop, ready to run, exhaust routed outside to do your testing on?..
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Post by Scoutpilot on Nov 11, 2019 14:34:03 GMT -5
Any updates Boss? Wouldn't it be cool to have dedicated L and F134s on stands in the shop, ready to run, exhaust routed outside to do your testing on?.. |
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Post by Scoutpilot on Dec 5, 2019 14:56:08 GMT -5
UPDATE: The problem turned out to be simultaneous multiple spark plug failures. Autolite 295's. Numbers 1 AND 2 went toes up. I replaced all four.
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oilleaker1
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Post by oilleaker1 on Dec 5, 2019 16:44:47 GMT -5
UPDATE: The problem turned out to be simultaneous multiple spark plug failures. Autolite 295's. Numbers 1 AND 2 went toes up. I replaced all four. My Willys pickup is putting steady in the exhaust. Seems to be # 2 when I pull wires on and off. If valves look good/not tight, plugs are next. Carb adjustment makes no difference either. We all get tested with our Jeeps. |
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